diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..fe3e0e7
Binary files /dev/null and b/.DS_Store differ
diff --git a/.gitignore b/.gitignore
index b8bd026..8970dbf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,3 +26,5 @@
 *.exe
 *.out
 *.app
+
+*.bin
diff --git a/README.md b/README.md
index 906807f..144b9b8 100644
--- a/README.md
+++ b/README.md
@@ -35,130 +35,6 @@ Connect according to the table below, and as seen in the figure below.
 
 ![Alphasense OPC-N2](https://github.com/dhhagan/opcn2/blob/master/opcn2-photon-wiring.png)
 
-# Documentation
 
-A brief overview of the functionality of this package follows below. For a more thorough overview,
-please check out the [python version of this code][1].
-
-### `class OPCN2(uint8_t chip_select)`
-
-> **chip_select**: Chip Select pin for SPI communication.
-
-> *Returns*: An instance of the OPCN2 class.
-
-#### `bool ping()`
-
-> Issues the `check_status` command and returns true if a connection is good.
-
-#### `bool on()`
-
-> Turn on the OPC laser and fan. Returns `true` if it works.
-
-#### `bool off()`
-
-> Turn off the OPC laser and fan. Returns `true` if it works.
-
-#### `bool write_config_variables( byte values[] )`
-
-> **NOT IMPLEMENTED (yet)**
-
-#### `bool write_config_variables2( byte values[] )`
-
-> **NOT IMPLEMENTED (yet)**
-
-#### `bool write_serial_number_string( byte values[] )`
-
-> **NOT IMPLEMENTED (yet)**
-
-#### `bool save_config_variables()`
-
-> Saves the configuration variables once changed. To be used in conjunction with
-> `enter_bootloader`.
-
-> *Returns:* boolean (true if successfull).
-
-#### `bool enter_bootloader()`
-
-> Enter into the bootloader to make permanent changes to configuration variables.
-> Use only if you know what you're doing!
-
-> *Returns:* boolean (true if successfull).
-
-#### `bool set_fan_power( uint8_t value )`
-
-> **value**: a uint8_t that corresponds to the desired fan power. Permitted values
-> are between 0 - 255.
-
-> *Returns:* boolean (true if successfull).
-
-#### `bool set_laser_power( uint8_t value )`
-
-> **value**: a uint8_t that corresponds to the desired laser power. Permitted values
-> are between 0 - 255.
-
-> *Returns:* boolean (true if successfull).
-
-#### `bool toggle_fan( bool state )`
-
-> **state**: true to turn the fan on, and false to turn it off.
-
-> *Returns:* boolean (true if successfull).
-
-#### `bool toggle_laser( bool state )`
-
-> **state**: true to turn the laser on, and false to turn it off.
-
-> *Returns:* boolean (true if successfull).
-
-#### `String read_information_string()`
-
-> Returns a String containing the OPC firmware version and serial number.
-
-#### `String read_serial_number()`
-
-> **Only available for firmware versions >= 18**
-
-> *Returns:* a String containing the serial number.
-
-#### `Firmware read_firmware_version()`
-
-> *Returns*: a structure containing: `Firmware.major` and `Firmware.minor`.
-
-#### `Status read_status()`
-
-> **Only available for firmware versions >= 18**
-
-> *Returns*: structure containing: `Status.fanON`, `Status.laserON`,
-> `Status.fanDAC`, and `Status.laserDAC`.
-
-#### `ConfigVars read_configuration_variables()`
-
-> *Returns:* the ConfigVars structure which contains: `ConfigVars.bb0` -
-> `ConfigVars.bb14`, `ConfigVars.bpv0` - `ConfigVars.bpv15`, `ConfigVars.bpd0` -
-> `ConfigVars.bpd15`, `ConfigVars.bsvw0` - `ConfigVars.bsvw15`, `ConfigVars.gsc`,
-> `ConfigVars.sfr`, `ConfigVars.laser_dac`, `ConfigVars.fan_dac`, and `ConfigVars.tof_sfr`.
-
-#### `ConfigVars2 read_configuration_variables2()`
-
-> **Only available for firmware versions >= 18**
-
-> *Returns:* the ConfigVars2 structure which contains: `ConfigVars2.AMSamplingInterval`,
-> `ConfigVars2.AMIntervalCount`, `ConfigVars2.AMFanOnIdle`, `ConfigVars2.AMLaserOnIdle`,
-> `ConfigVars2.AMMaxDataArraysInFile`, and `ConfigVars2.AMOnlySavePMData`.
-
-#### `PMData read_pm_data()`
-
-> **Only available for firmware versions >= 18**
-
-> *Returns:* the PMData structure containing: `PMData.pm1`, `PMData.pm25`, and `PMData.pm10`.
-
-#### `HistogramData read_histogram( bool convert_to_conc )`
-
-> **convert_to_conc:** (boolean) If true, the raw histogram is converted to concentration
-> (#/cm3) by dividing the raw value by the product of the sampling period and the sample flow rate.
-
-> *Returns:* the HistogramData structure containing: `period`, `sfr`, `bin0` - `bin15`,
-> `bin1MToF`, `bin3MToF`, `bin5MToF`, `bin7MToF`, `temp_pressure`, `checksum`,
-> `pm1`, `pm25`, and `pm10`.
 
 [1]: https://github.com/dhhagan/py-opc
diff --git a/doc/index.md b/doc/index.md
new file mode 100644
index 0000000..2bf7dc8
--- /dev/null
+++ b/doc/index.md
@@ -0,0 +1,125 @@
+# Documentation
+
+A brief overview of the functionality of this package follows below. For a more thorough overview,
+please check out the [python version of this code][1].
+
+### `class OPCN2(uint8_t chip_select)`
+
+> **chip_select**: Chip Select pin for SPI communication.
+
+> *Returns*: An instance of the OPCN2 class.
+
+#### `bool ping()`
+
+> Issues the `check_status` command and returns true if a connection is good.
+
+#### `bool on()`
+
+> Turn on the OPC laser and fan. Returns `true` if it works.
+
+#### `bool off()`
+
+> Turn off the OPC laser and fan. Returns `true` if it works.
+
+#### `bool write_config_variables( byte values[] )`
+
+> **NOT IMPLEMENTED (yet)**
+
+#### `bool write_config_variables2( byte values[] )`
+
+> **NOT IMPLEMENTED (yet)**
+
+#### `bool write_serial_number_string( byte values[] )`
+
+> **NOT IMPLEMENTED (yet)**
+
+#### `bool save_config_variables()`
+
+> Saves the configuration variables once changed. To be used in conjunction with
+> `enter_bootloader`.
+
+> *Returns:* boolean (true if successfull).
+
+#### `bool enter_bootloader()`
+
+> Enter into the bootloader to make permanent changes to configuration variables.
+> Use only if you know what you're doing!
+
+> *Returns:* boolean (true if successfull).
+
+#### `bool set_fan_power( uint8_t value )`
+
+> **value**: a uint8_t that corresponds to the desired fan power. Permitted values
+> are between 0 - 255.
+
+> *Returns:* boolean (true if successfull).
+
+#### `bool set_laser_power( uint8_t value )`
+
+> **value**: a uint8_t that corresponds to the desired laser power. Permitted values
+> are between 0 - 255.
+
+> *Returns:* boolean (true if successfull).
+
+#### `bool toggle_fan( bool state )`
+
+> **state**: true to turn the fan on, and false to turn it off.
+
+> *Returns:* boolean (true if successfull).
+
+#### `bool toggle_laser( bool state )`
+
+> **state**: true to turn the laser on, and false to turn it off.
+
+> *Returns:* boolean (true if successfull).
+
+#### `String read_information_string()`
+
+> Returns a String containing the OPC firmware version and serial number.
+
+#### `String read_serial_number()`
+
+> **Only available for firmware versions >= 18**
+
+> *Returns:* a String containing the serial number.
+
+#### `Firmware read_firmware_version()`
+
+> *Returns*: a structure containing: `Firmware.major` and `Firmware.minor`.
+
+#### `Status read_status()`
+
+> **Only available for firmware versions >= 18**
+
+> *Returns*: structure containing: `Status.fanON`, `Status.laserON`,
+> `Status.fanDAC`, and `Status.laserDAC`.
+
+#### `ConfigVars read_configuration_variables()`
+
+> *Returns:* the ConfigVars structure which contains: `ConfigVars.bb0` -
+> `ConfigVars.bb14`, `ConfigVars.bpv0` - `ConfigVars.bpv15`, `ConfigVars.bpd0` -
+> `ConfigVars.bpd15`, `ConfigVars.bsvw0` - `ConfigVars.bsvw15`, `ConfigVars.gsc`,
+> `ConfigVars.sfr`, `ConfigVars.laser_dac`, `ConfigVars.fan_dac`, and `ConfigVars.tof_sfr`.
+
+#### `ConfigVars2 read_configuration_variables2()`
+
+> **Only available for firmware versions >= 18**
+
+> *Returns:* the ConfigVars2 structure which contains: `ConfigVars2.AMSamplingInterval`,
+> `ConfigVars2.AMIntervalCount`, `ConfigVars2.AMFanOnIdle`, `ConfigVars2.AMLaserOnIdle`,
+> `ConfigVars2.AMMaxDataArraysInFile`, and `ConfigVars2.AMOnlySavePMData`.
+
+#### `PMData read_pm_data()`
+
+> **Only available for firmware versions >= 18**
+
+> *Returns:* the PMData structure containing: `PMData.pm1`, `PMData.pm25`, and `PMData.pm10`.
+
+#### `HistogramData read_histogram( bool convert_to_conc )`
+
+> **convert_to_conc:** (boolean) If true, the raw histogram is converted to concentration
+> (#/cm3) by dividing the raw value by the product of the sampling period and the sample flow rate.
+
+> *Returns:* the HistogramData structure containing: `period`, `sfr`, `bin0` - `bin15`,
+> `bin1MToF`, `bin3MToF`, `bin5MToF`, `bin7MToF`, `temp_pressure`, `checksum`,
+> `pm1`, `pm25`, and `pm10`.
diff --git a/firmware/examples/opcn2-examples.cpp b/examples/run-the-opc/opcn2-examples.cpp
similarity index 98%
rename from firmware/examples/opcn2-examples.cpp
rename to examples/run-the-opc/opcn2-examples.cpp
index 43b9d08..e5e1630 100644
--- a/firmware/examples/opcn2-examples.cpp
+++ b/examples/run-the-opc/opcn2-examples.cpp
@@ -6,7 +6,7 @@
   Written by David H Hagan, June 2016
 */
 
-#include "opcn2/opcn2.h"
+#include "opcn2.h"
 
 #define CS A2
 
diff --git a/firmware/examples/tests.cpp b/examples/tests/tests.cpp
similarity index 99%
rename from firmware/examples/tests.cpp
rename to examples/tests/tests.cpp
index 2cfdf67..f6bd539 100644
--- a/firmware/examples/tests.cpp
+++ b/examples/tests/tests.cpp
@@ -2,7 +2,7 @@
   Run tests for the entire OPC-N2 library.
 */
 
-#include "opcn2/opcn2.h"
+#include "opcn2.h"
 
 #define CS A2
 
diff --git a/firmware/opcn2.cpp b/firmware/opcn2.cpp
deleted file mode 100644
index ab9b58e..0000000
--- a/firmware/opcn2.cpp
+++ /dev/null
@@ -1,628 +0,0 @@
-#include "opcn2.h"
-
-OPCN2::OPCN2(uint8_t chip_select){
-    _CS = chip_select;
-
-    // Set up SPI
-    SPI.begin(_CS);
-    SPI.setBitOrder(MSBFIRST);
-    SPI.setDataMode(SPI_MODE1);
-    SPI.setClockSpeed(1000000);
-
-    // Set the firmware version
-    _fv = this->read_information_string().replace(".", "").trim().substring(24, 26).toInt();
-
-    if (_fv < 18) {
-      firm_ver.major = _fv;
-      firm_ver.minor = 0;
-    }
-    else {
-      firm_ver.major = 99;    // only temporarily...
-      Firmware tmp = this->read_firmware_version();
-
-      firm_ver.major = tmp.major;
-      firm_ver.minor = tmp.minor;
-    }
-}
-
-uint16_t OPCN2::_16bit_int(byte LSB, byte MSB){
-    // Combine two bytes into a 16-bit unsigned int
-    return ((MSB << 8) | LSB);
-}
-
-bool OPCN2::_compare_arrays(byte array1[], byte array2[], int length){
-    // Compare two arrays
-    bool result = true;
-
-    for (int i = 0; i < length; i++){
-        if (array1[i] != array2[i]){
-            result = false;
-        }
-    }
-
-    return result;
-}
-
-float OPCN2::_calculate_float(byte val0, byte val1, byte val2, byte val3){
-    // Return an IEEE754 float from an array of 4 bytes
-    union u_tag {
-        byte b[4];
-        float val;
-    } u;
-
-    u.b[0] = val0;
-    u.b[1] = val1;
-    u.b[2] = val2;
-    u.b[3] = val3;
-
-    return u.val;
-}
-
-uint32_t OPCN2::_32bit_int(byte val0, byte val1, byte val2, byte val3){
-    // Return a 32-bit unsigned int from 4 bytes
-    return ((val3 << 24) | (val2 << 16) | (val1 << 8) | val0);
-}
-
-bool OPCN2::ping(){
-    // Isse the check status command
-    byte resp[1];
-    byte expected[] = {0xF3};
-
-    digitalWrite(this->_CS, LOW);       // pull the pin low
-    resp[0] = SPI.transfer(0xCF);       // issue the command byte
-    digitalWrite(this->_CS, HIGH);      // pull the pin high
-
-    return this->_compare_arrays(resp, expected, 1);
-}
-
-bool OPCN2::on(){
-    // Turn ON the OPC
-    byte vals[2];
-    byte expected[] = {0xF3, 0x03};
-
-    digitalWrite(this->_CS, LOW);
-    vals[0] = SPI.transfer(0x03);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    vals[1] = SPI.transfer(0x00);
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(vals, expected, 2);
-}
-
-bool OPCN2::off(){
-    // Turn OFF the OPC
-    byte vals[2];
-    byte expected[] = {0xF3, 0x03};
-
-    digitalWrite(this->_CS, LOW);
-    vals[0] = SPI.transfer(0x03);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    vals[1] = SPI.transfer(0x01);
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(vals, expected, 2);
-}
-
-String OPCN2::read_information_string(){
-    String result = "";
-    String tmp;
-    byte vals[61];
-
-    digitalWrite(this->_CS, LOW);
-    SPI.transfer(0x3F);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(3);
-
-    // Iterate to read the entire string
-    digitalWrite(this->_CS, LOW);
-    for (int i = 0; i < 60; i++){
-        vals[i] = SPI.transfer(0x00);
-        result += String((char)vals[i]);
-        delayMicroseconds(4);
-    }
-
-    digitalWrite(this->_CS, HIGH);
-
-    return result;
-}
-
-struct Status OPCN2::read_status(){
-  // Read key status variables from the OPC-N2
-  // Only available with Alphasense OPC-N2 > firmware v18
-  Status data;
-  byte vals[4];
-
-  if (this->firm_ver.major < 18) {
-    data.fanON    = -999;
-    data.laserON  = -999;
-    data.fanDAC   = -999;
-    data.laserDAC = -999;
-  }
-  else {
-    // Read the status
-    digitalWrite(this->_CS, LOW);
-    SPI.transfer(0x13);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    // Send the read command and build the array of data
-    digitalWrite(this->_CS, LOW);
-    for (int i = 0; i < 4; i++){
-      vals[i] = SPI.transfer(0x13);
-      delayMicroseconds(4);
-    }
-
-    digitalWrite(this->_CS, HIGH);
-
-    // Calculate the values!
-    data.fanON    = (unsigned int)vals[0];
-    data.laserON  = (unsigned int)vals[1];
-    data.fanDAC   = (unsigned int)vals[2];
-    data.laserDAC = (unsigned int)vals[3];
-  }
-
-  return data;
-}
-
-struct Firmware OPCN2::read_firmware_version(){
-  // Only available with Alphasense OPC-N2 > firmware v18
-  Firmware res;
-
-  if (this->firm_ver.major < 18) {
-    res.major = -999;
-    res.minor = -999;
-  }
-  else {
-    // Read the Firmware version
-    digitalWrite(this->_CS, LOW);
-    SPI.transfer(0x12);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    res.major = (unsigned int)SPI.transfer(0x00);
-    delayMicroseconds(4);
-    res.minor = (unsigned int)SPI.transfer(0x00);
-    digitalWrite(this->_CS, HIGH);
-  }
-
-  return res;
-}
-
-bool OPCN2::write_config_variables(byte values[]){
-    // Write the configuration [NOT IMPLEMENTED]
-
-    return true;
-}
-
-bool OPCN2::write_config_variables2(byte values[]){
-    // Write the configuration [NOT IMPLEMENTED]
-    // Only available with Alphasense OPC-N2 > firmware v18
-
-    return true;
-}
-
-bool OPCN2::write_serial_number_string(byte values[]){
-  // NOT IMPLEMENTED
-  // Only available with Alphasense OPC-N2 > firmware v18
-
-
-  return true;
-}
-
-bool OPCN2::save_config_variables(){
-    // Save the config variables
-    byte resp[6];
-    byte commands[] = {0x43, 0x3F, 0x3C, 0x3F, 0x3C, 0x43};
-    byte expected[] = {0xF3, 0x43, 0x3f, 0x3c, 0x3f, 0x3c};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(commands[0]);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    for (int i = 1; i < (int)sizeof(commands); i++){
-        resp[i] = SPI.transfer(commands[i]);
-        delayMicroseconds(4);
-    }
-
-    digitalWrite(this->_CS, HIGH);      // Pull the pin high
-
-    return this->_compare_arrays(resp, expected, 6);
-}
-
-bool OPCN2::enter_bootloader(){
-    byte resp[1];
-    byte expected[] = {0xF3};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(0x41);
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(resp, expected, 1);
-}
-
-bool OPCN2::set_fan_power(uint8_t value){
-    byte resp[3];
-    byte expected[] = {0xF3, 0x42, 0x00};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(0x42);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    resp[1] = SPI.transfer(0x00);
-
-    delayMicroseconds(4);
-
-    resp[2] = SPI.transfer(value);
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(resp, expected, 3);
-}
-
-bool OPCN2::set_laser_power(uint8_t value){
-    byte resp[3];
-    byte expected[] = {0xF3, 0x42, 0x01};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(0x42);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    resp[1] = SPI.transfer(0x01);
-
-    delayMicroseconds(4);
-
-    resp[2] = SPI.transfer(value);
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(resp, expected, 3);
-}
-
-bool OPCN2::toggle_fan(bool state){
-    byte resp[2];
-    byte expected[] = {0xF3, 0x03};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(0x03);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    // turn either on or off
-    digitalWrite(this->_CS, LOW);
-    if (state == true){
-        resp[1] = SPI.transfer(0x04);
-    }
-    else {
-        resp[1] = SPI.transfer(0x05);
-    }
-
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(resp, expected, 2);
-}
-
-bool OPCN2::toggle_laser(bool state){
-    byte resp[2];
-    byte expected[] = {0xF3, 0x03};
-
-    digitalWrite(this->_CS, LOW);
-    resp[0] = SPI.transfer(0x03);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    if (state == true){
-        resp[1] = SPI.transfer(0x02);
-    }
-    else {
-        resp[1] = SPI.transfer(0x03);
-    }
-
-    digitalWrite(this->_CS, HIGH);
-
-    return this->_compare_arrays(resp, expected, 2);
-}
-
-struct ConfigVars OPCN2::read_configuration_variables(){
-    ConfigVars results;       // empty structure for the data
-    byte vals[256];
-
-    // Read the config variables
-    digitalWrite(this->_CS, LOW);
-    SPI.transfer(0x3c);
-    digitalWrite(this->_CS, HIGH);
-
-    delay(10);
-
-    digitalWrite(this->_CS, LOW);
-    for (int i = 0; i < 256; i++){
-        vals[i] = SPI.transfer(0x00);
-        delayMicroseconds(4);
-    }
-
-    digitalWrite(this->_CS, HIGH);
-
-    // Fill in the results
-    results.bb0 = this->_16bit_int(vals[0], vals[1]);
-    results.bb1 = this->_16bit_int(vals[2], vals[3]);
-    results.bb2 = this->_16bit_int(vals[4], vals[5]);
-    results.bb3 = this->_16bit_int(vals[6], vals[7]);
-    results.bb4 = this->_16bit_int(vals[8], vals[9]);
-    results.bb5 = this->_16bit_int(vals[10], vals[11]);
-    results.bb6 = this->_16bit_int(vals[12], vals[13]);
-    results.bb7 = this->_16bit_int(vals[14], vals[15]);
-    results.bb8 = this->_16bit_int(vals[16], vals[17]);
-    results.bb9 = this->_16bit_int(vals[18], vals[19]);
-    results.bb10 = this->_16bit_int(vals[20], vals[21]);
-    results.bb11 = this->_16bit_int(vals[22], vals[23]);
-    results.bb12 = this->_16bit_int(vals[24], vals[25]);
-    results.bb13 = this->_16bit_int(vals[26], vals[27]);
-    results.bb14 = this->_16bit_int(vals[28], vals[29]);
-
-    // Bin Particle Volumes
-    results.bpv0 = this->_calculate_float(vals[32], vals[33], vals[34], vals[35]);
-    results.bpv1 = this->_calculate_float(vals[36], vals[37], vals[38], vals[39]);
-    results.bpv2 = this->_calculate_float(vals[40], vals[41], vals[42], vals[43]);
-    results.bpv3 = this->_calculate_float(vals[44], vals[45], vals[46], vals[47]);
-    results.bpv4 = this->_calculate_float(vals[48], vals[49], vals[50], vals[51]);
-    results.bpv5 = this->_calculate_float(vals[52], vals[53], vals[54], vals[55]);
-    results.bpv6 = this->_calculate_float(vals[56], vals[57], vals[58], vals[59]);
-    results.bpv7 = this->_calculate_float(vals[60], vals[61], vals[62], vals[63]);
-    results.bpv8 = this->_calculate_float(vals[64], vals[65], vals[66], vals[67]);
-    results.bpv9 = this->_calculate_float(vals[68], vals[69], vals[70], vals[71]);
-    results.bpv10 = this->_calculate_float(vals[72], vals[73], vals[74], vals[75]);
-    results.bpv11 = this->_calculate_float(vals[76], vals[77], vals[78], vals[79]);
-    results.bpv12 = this->_calculate_float(vals[80], vals[81], vals[82], vals[83]);
-    results.bpv13 = this->_calculate_float(vals[84], vals[85], vals[86], vals[87]);
-    results.bpv14 = this->_calculate_float(vals[88], vals[89], vals[90], vals[91]);
-    results.bpv15 = this->_calculate_float(vals[92], vals[93], vals[94], vals[95]);
-
-    // Bin Particle Densities
-    results.bpd0 = this->_calculate_float(vals[96], vals[97], vals[98], vals[99]);
-    results.bpd1 = this->_calculate_float(vals[100], vals[101], vals[102], vals[103]);
-    results.bpd2 = this->_calculate_float(vals[104], vals[105], vals[106], vals[107]);
-    results.bpd3 = this->_calculate_float(vals[108], vals[109], vals[110], vals[111]);
-    results.bpd4 = this->_calculate_float(vals[112], vals[113], vals[114], vals[115]);
-    results.bpd5 = this->_calculate_float(vals[116], vals[117], vals[118], vals[119]);
-    results.bpd6 = this->_calculate_float(vals[120], vals[121], vals[122], vals[123]);
-    results.bpd7 = this->_calculate_float(vals[124], vals[125], vals[126], vals[127]);
-    results.bpd8 = this->_calculate_float(vals[128], vals[129], vals[130], vals[131]);
-    results.bpd9 = this->_calculate_float(vals[132], vals[133], vals[134], vals[135]);
-    results.bpd10 = this->_calculate_float(vals[136], vals[137], vals[138], vals[139]);
-    results.bpd11 = this->_calculate_float(vals[140], vals[141], vals[142], vals[143]);
-    results.bpd12 = this->_calculate_float(vals[144], vals[145], vals[146], vals[147]);
-    results.bpd13 = this->_calculate_float(vals[148], vals[149], vals[150], vals[151]);
-    results.bpd14 = this->_calculate_float(vals[152], vals[153], vals[154], vals[155]);
-    results.bpd15 = this->_calculate_float(vals[156], vals[157], vals[158], vals[159]);
-
-    // Bin Particle Sample Volumes
-    results.bsvw0 = this->_calculate_float(vals[160], vals[161], vals[162], vals[163]);
-    results.bsvw1 = this->_calculate_float(vals[164], vals[165], vals[166], vals[167]);
-    results.bsvw2 = this->_calculate_float(vals[168], vals[169], vals[170], vals[171]);
-    results.bsvw3 = this->_calculate_float(vals[172], vals[173], vals[174], vals[175]);
-    results.bsvw4 = this->_calculate_float(vals[176], vals[177], vals[178], vals[179]);
-    results.bsvw5 = this->_calculate_float(vals[180], vals[181], vals[182], vals[183]);
-    results.bsvw6 = this->_calculate_float(vals[184], vals[185], vals[186], vals[187]);
-    results.bsvw7 = this->_calculate_float(vals[188], vals[189], vals[190], vals[191]);
-    results.bsvw8 = this->_calculate_float(vals[192], vals[193], vals[194], vals[195]);
-    results.bsvw9 = this->_calculate_float(vals[196], vals[197], vals[198], vals[199]);
-    results.bsvw10 = this->_calculate_float(vals[200], vals[201], vals[202], vals[203]);
-    results.bsvw11 = this->_calculate_float(vals[204], vals[205], vals[206], vals[207]);
-    results.bsvw12 = this->_calculate_float(vals[208], vals[209], vals[210], vals[211]);
-    results.bsvw13 = this->_calculate_float(vals[212], vals[213], vals[214], vals[215]);
-    results.bsvw14 = this->_calculate_float(vals[216], vals[217], vals[218], vals[219]);
-    results.bsvw15 = this->_calculate_float(vals[220], vals[221], vals[222], vals[223]);
-
-    // Gain Scaling Coefficient
-    results.gsc = this->_calculate_float(vals[224], vals[225], vals[226], vals[227]);
-
-    // Sample Flow Rate (ml/s)
-    results.sfr = this->_calculate_float(vals[228], vals[229], vals[230], vals[231]);
-
-    // LaserDAC
-    results.laser_dac = (unsigned int)vals[232];
-    results.fan_dac = (unsigned int)vals[233];
-
-    // Time-of-Flight to Sample Flow Rate ratio
-    results.tof_sfr = (unsigned int)vals[234];
-
-    return results;
-}
-
-struct ConfigVars2 OPCN2::read_configuration_variables2(){
-    ConfigVars2 results;       // empty structure for the data
-    byte vals[9];
-
-    if (this->firm_ver.major < 18) {
-        results.AMSamplingInterval    = -999;
-        results.AMIntervalCount       = -999;
-        results.AMFanOnIdle           = -999;
-        results.AMLaserOnIdle         = -999;
-        results.AMMaxDataArraysInFile = -999;
-        results.AMOnlySavePMData      = -999;
-    }
-    else {
-        // Read the config variables
-        digitalWrite(this->_CS, LOW);
-        SPI.transfer(0x3D);
-        digitalWrite(this->_CS, HIGH);
-
-        delay(10);
-
-        digitalWrite(this->_CS, LOW);
-        for (int i = 0; i < 9; i++){
-            vals[i] = SPI.transfer(0x00);
-            delayMicroseconds(4);
-        }
-
-        digitalWrite(this->_CS, HIGH);
-
-        // Fill in the results
-        results.AMSamplingInterval    = this->_16bit_int(vals[0], vals[1]);
-        results.AMIntervalCount       = this->_16bit_int(vals[2], vals[3]);
-        results.AMFanOnIdle           = (unsigned int)vals[4];
-        results.AMLaserOnIdle         = (unsigned int)vals[5];
-        results.AMMaxDataArraysInFile = this->_16bit_int(vals[6], vals[7]);
-        results.AMOnlySavePMData      = (unsigned int)vals[8];
-    }
-
-    return results;
-}
-
-String OPCN2::read_serial_number(){
-    String result = "";
-    byte vals[60];
-
-    if (this->firm_ver.major < 18) {
-        result = "";
-    }
-    else {
-        digitalWrite(this->_CS, LOW);       // Pull the CS low
-        SPI.transfer(0x10);                 // Send the start command
-        digitalWrite(this->_CS, HIGH);       // Pull the CS High
-
-        delay(3);
-
-        // Iterate to read the entire string
-        digitalWrite(this->_CS, LOW);
-        for (int i = 0; i < 61; i++){
-            vals[i] = SPI.transfer(0x00);
-            result += String((char)vals[i]);
-            delayMicroseconds(4);
-        }
-
-        digitalWrite(this->_CS, HIGH);
-    }
-
-    result = result.trim();
-
-    return result;
-}
-
-struct PMData OPCN2::read_pm_data(){
-  // Read the PM Data and reset the histogram
-  PMData data;
-  byte vals[12];
-
-  if (this->firm_ver.major < 18) {
-      data.pm1  = -999;
-      data.pm25 = -999;
-      data.pm10 = -999;
-  }
-  else {
-      // Read the data and clear the local memory
-      digitalWrite(this->_CS, LOW);       // Pull the CS Low
-      SPI.transfer(0x32);                 // Transfer the command byte
-      digitalWrite(this->_CS, HIGH);
-
-      delay(12);                          // Delay for 12 ms
-
-      // Send commands and build array of data
-      digitalWrite(this->_CS, LOW);
-
-      for (int i = 0; i < 12; i++){
-          vals[i] = SPI.transfer(0x00);
-          delayMicroseconds(4);
-      }
-
-      digitalWrite(this->_CS, HIGH);      // Pull the CS High
-
-      data.pm1  = this->_calculate_float(vals[0], vals[1], vals[2], vals[3]);
-      data.pm25 = this->_calculate_float(vals[4], vals[5], vals[6], vals[7]);
-      data.pm10 = this->_calculate_float(vals[8], vals[9], vals[10], vals[11]);
-  }
-
-  return data;
-}
-
-struct HistogramData OPCN2::read_histogram(bool convert_to_conc){
-    HistogramData data;
-    byte vals[62];
-
-    // Read the data and clear the local memory
-    digitalWrite(this->_CS, LOW);       // Pull the CS Low
-    SPI.transfer(0x30);                 // Transfer the command byte
-    digitalWrite(this->_CS, HIGH);
-
-    delay(12);                          // Delay for 12 ms
-
-    // Send commands and build array of data
-    digitalWrite(this->_CS, LOW);
-
-    for (int i = 0; i < 62; i++){
-        vals[i] = SPI.transfer(0x00);
-        delayMicroseconds(4);
-    }
-
-    digitalWrite(this->_CS, HIGH);      // Pull the CS High
-
-    data.period = this->_calculate_float(vals[44], vals[45], vals[46], vals[47]);
-    data.sfr    = this->_calculate_float(vals[36], vals[37], vals[38], vals[39]);
-
-    // If convert_to_conc = True, convert from raw data to concentration
-    double conv;
-
-    if ( convert_to_conc != true ) {
-        conv = 1.0;
-    }
-    else {
-        conv = data.sfr * data.period;
-    }
-
-    // Calculate all of the values!
-    data.bin0   = this->_16bit_int(vals[0], vals[1]) / conv;
-    data.bin1   = this->_16bit_int(vals[2], vals[3]) / conv;
-    data.bin2   = this->_16bit_int(vals[4], vals[5]) / conv;
-    data.bin3   = this->_16bit_int(vals[6], vals[7]) / conv;
-    data.bin4   = this->_16bit_int(vals[8], vals[9]) / conv;
-    data.bin5   = this->_16bit_int(vals[10], vals[11]) / conv;
-    data.bin6   = this->_16bit_int(vals[12], vals[13]) / conv;
-    data.bin7   = this->_16bit_int(vals[14], vals[15]) / conv;
-    data.bin8   = this->_16bit_int(vals[16], vals[17]) / conv;
-    data.bin9   = this->_16bit_int(vals[18], vals[19]) / conv;
-    data.bin10  = this->_16bit_int(vals[20], vals[21]) / conv;
-    data.bin11  = this->_16bit_int(vals[22], vals[23]) / conv;
-    data.bin12  = this->_16bit_int(vals[24], vals[25]) / conv;
-    data.bin13  = this->_16bit_int(vals[26], vals[27]) / conv;
-    data.bin14  = this->_16bit_int(vals[28], vals[29]) / conv;
-    data.bin15  = this->_16bit_int(vals[30], vals[31]) / conv;
-
-    data.bin1MToF = int(vals[32]) / 3.0;
-    data.bin3MToF = int(vals[33]) / 3.0;
-    data.bin5MToF = int(vals[34]) / 3.0;
-    data.bin7MToF = int(vals[35]) / 3.0;
-
-    // This holds either temperature or pressure
-    // If temp, this is temp in C x 10
-    // If pressure, this is pressure in Pa
-    data.temp_pressure = this->_32bit_int(vals[40], vals[41], vals[42], vals[43]);
-
-    data.checksum = this->_16bit_int(vals[48], vals[49]);
-
-    data.pm1 = this->_calculate_float(vals[50], vals[51], vals[52], vals[53]);
-    data.pm25 = this->_calculate_float(vals[54], vals[55], vals[56], vals[57]);
-    data.pm10 = this->_calculate_float(vals[58], vals[59], vals[60], vals[61]);
-
-    return data;
-}
diff --git a/library.properties b/library.properties
new file mode 100644
index 0000000..73f14bb
--- /dev/null
+++ b/library.properties
@@ -0,0 +1,10 @@
+name=opcn2
+version=1.0.0
+license=MIT
+author=David H Hagan <dhagan@mit.edu>
+maintainer=David H Hagan <dhagan@mit.edu>
+sentence=A simple library to operate the Alphasense OPC-N2 from a Particle Photon/Electron
+category=Science
+url=https://github.com/dhhagan/opcn2
+repository=https://github.com/dhhagan/opcn2.git
+dependencies.opcn2=1.0.0
diff --git a/spark.json b/spark.json
deleted file mode 100644
index 9d38c8e..0000000
--- a/spark.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-  "name": "opcn2",
-  "author": "David H Hagan <david@davidhhagan.com>",
-  "license": "MIT",
-  "version": "0.4.0",
-  "description": "A simple library to operate the Alphasense OPC-N2 from a Particle Photon/Electron"
-}
diff --git a/firmware/keywords.txt b/src/keywords.txt
similarity index 100%
rename from firmware/keywords.txt
rename to src/keywords.txt
diff --git a/src/opcn2.cpp b/src/opcn2.cpp
new file mode 100644
index 0000000..8d0e690
--- /dev/null
+++ b/src/opcn2.cpp
@@ -0,0 +1,704 @@
+#include "opcn2.h"
+
+OPCN2::OPCN2(uint8_t chip_select)
+{
+  // Initiate an instance of the OPCN2 class
+  // Ex. OPCN2 alpha(chip_select = A2);
+  _CS = chip_select;
+
+  // Set up SPI
+  SPI.begin(_CS);
+  SPI.setBitOrder(MSBFIRST);
+  SPI.setDataMode(SPI_MODE1);
+  SPI.setClockSpeed(1000000);
+
+  // Set the firmware version
+  _fv = this->read_information_string().replace(".", "").trim().substring(24, 26).toInt();
+
+  if (_fv < 18) {
+    firm_ver.major = _fv;
+    firm_ver.minor = 0;
+  }
+  else {
+    firm_ver.major = 99;    // only temporarily...
+    Firmware tmp = this->read_firmware_version();
+
+    firm_ver.major = tmp.major;
+    firm_ver.minor = tmp.minor;
+  }
+}
+
+uint16_t OPCN2::_16bit_int(byte LSB, byte MSB)
+{
+  // Combine two bytes into a 16-bit unsigned int
+  return ((MSB << 8) | LSB);
+}
+
+bool OPCN2::_compare_arrays(byte array1[], byte array2[], int length)
+{
+  // Compare two arrays and return a boolean
+  bool result = true;
+
+  for (int i = 0; i < length; i++){
+    if (array1[i] != array2[i]){
+      result = false;
+    }
+  }
+
+  return result;
+}
+
+float OPCN2::_calculate_float(byte val0, byte val1, byte val2, byte val3)
+{
+  // Return an IEEE754 float from an array of 4 bytes
+  union u_tag {
+    byte b[4];
+    float val;
+  } u;
+
+  u.b[0] = val0;
+  u.b[1] = val1;
+  u.b[2] = val2;
+  u.b[3] = val3;
+
+  return u.val;
+}
+
+uint32_t OPCN2::_32bit_int(byte val0, byte val1, byte val2, byte val3)
+{
+  // Return a 32-bit unsigned int from 4 bytes
+  return ((val3 << 24) | (val2 << 16) | (val1 << 8) | val0);
+}
+
+bool OPCN2::ping()
+{
+  // Isse the check status command
+  // ex.
+  // $ alpha.ping();
+  // $ true
+  byte resp[1];
+  byte expected[] = {0xF3};
+
+  digitalWrite(this->_CS, LOW);       // pull the pin low
+  resp[0] = SPI.transfer(0xCF);       // issue the command byte
+  digitalWrite(this->_CS, HIGH);      // pull the pin high
+
+  return this->_compare_arrays(resp, expected, 1);
+}
+
+bool OPCN2::on()
+{
+  // Turn ON the OPC and return a boolean
+  // Ex.
+  // $ alpha.on()
+  // $ true
+  byte vals[2];
+  byte expected[] = {0xF3, 0x03};
+
+  digitalWrite(this->_CS, LOW);
+  vals[0] = SPI.transfer(0x03);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  vals[1] = SPI.transfer(0x00);
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(vals, expected, 2);
+}
+
+bool OPCN2::off()
+{
+  // Turn OFF the OPC and return a boolean
+  // Ex.
+  // $ alpha.off()
+  // $ true
+  byte vals[2];
+  byte expected[] = {0xF3, 0x03};
+
+  digitalWrite(this->_CS, LOW);
+  vals[0] = SPI.transfer(0x03);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  vals[1] = SPI.transfer(0x01);
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(vals, expected, 2);
+}
+
+String OPCN2::read_information_string()
+{
+  // Read the information string and return a string
+  // Ex.
+  // $ alpha.read_information_string()
+  String result = "";
+  String tmp;
+  byte vals[61];
+
+  digitalWrite(this->_CS, LOW);
+  SPI.transfer(0x3F);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(3);
+
+  // Iterate to read the entire string
+  digitalWrite(this->_CS, LOW);
+  for (int i = 0; i < 60; i++){
+    vals[i] = SPI.transfer(0x00);
+    result += String((char)vals[i]);
+    delayMicroseconds(4);
+  }
+
+  digitalWrite(this->_CS, HIGH);
+
+  return result;
+}
+
+struct Status OPCN2::read_status()
+{
+  // Read key status variables from the OPC-N2
+  // Only available with Alphasense OPC-N2 > firmware v18
+  // Ex.
+  // $ alpha.read_status()
+  Status data;
+  byte vals[4];
+
+  if (this->firm_ver.major < 18) {
+    data.fanON    = -999;
+    data.laserON  = -999;
+    data.fanDAC   = -999;
+    data.laserDAC = -999;
+  }
+  else {
+    // Read the status
+    digitalWrite(this->_CS, LOW);
+    SPI.transfer(0x13);
+    digitalWrite(this->_CS, HIGH);
+
+    delay(10);
+
+    // Send the read command and build the array of data
+    digitalWrite(this->_CS, LOW);
+    for (int i = 0; i < 4; i++){
+      vals[i] = SPI.transfer(0x13);
+      delayMicroseconds(4);
+    }
+
+    digitalWrite(this->_CS, HIGH);
+
+    // Calculate the values!
+    data.fanON    = (unsigned int)vals[0];
+    data.laserON  = (unsigned int)vals[1];
+    data.fanDAC   = (unsigned int)vals[2];
+    data.laserDAC = (unsigned int)vals[3];
+  }
+
+  return data;
+}
+
+struct Firmware OPCN2::read_firmware_version()
+{
+  // Only available with Alphasense OPC-N2 > firmware v18
+  // Ex.
+  // $ alpha.read_firmware_version()
+  Firmware res;
+
+  if (this->firm_ver.major < 18) {
+    res.major = -999;
+    res.minor = -999;
+  }
+  else {
+    // Read the Firmware version
+    digitalWrite(this->_CS, LOW);
+    SPI.transfer(0x12);
+    digitalWrite(this->_CS, HIGH);
+
+    delay(10);
+
+    digitalWrite(this->_CS, LOW);
+    res.major = (unsigned int)SPI.transfer(0x00);
+    delayMicroseconds(4);
+    res.minor = (unsigned int)SPI.transfer(0x00);
+    digitalWrite(this->_CS, HIGH);
+  }
+
+  return res;
+}
+
+bool OPCN2::write_config_variables(byte values[])
+{
+  // Write the configuration [NOT IMPLEMENTED]
+  return true;
+}
+
+bool OPCN2::write_config_variables2(byte values[])
+{
+  // Write the configuration [NOT IMPLEMENTED]
+  // Only available with Alphasense OPC-N2 > firmware v18
+  return true;
+}
+
+bool OPCN2::write_serial_number_string(byte values[])
+{
+  // NOT IMPLEMENTED
+  // Only available with Alphasense OPC-N2 > firmware v18
+  return true;
+}
+
+bool OPCN2::save_config_variables()
+{
+  // Save the configuration variables
+  // Ex.
+  // $ alpha.save_config_variables()
+  byte resp[6];
+  byte commands[] = {0x43, 0x3F, 0x3C, 0x3F, 0x3C, 0x43};
+  byte expected[] = {0xF3, 0x43, 0x3f, 0x3c, 0x3f, 0x3c};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(commands[0]);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  for (int i = 1; i < (int)sizeof(commands); i++){
+    resp[i] = SPI.transfer(commands[i]);
+    delayMicroseconds(4);
+  }
+
+  digitalWrite(this->_CS, HIGH);      // Pull the pin high
+
+  return this->_compare_arrays(resp, expected, 6);
+}
+
+bool OPCN2::enter_bootloader()
+{
+  // Enter into bootloader mode
+  byte resp[1];
+  byte expected[] = {0xF3};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(0x41);
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(resp, expected, 1);
+}
+
+bool OPCN2::set_fan_power(uint8_t value)
+{
+  // Set the fan power
+  // Value must be between 0-255
+  // Ex.
+  // $ alpha.set_fan_power(255);
+  byte resp[3];
+  byte expected[] = {0xF3, 0x42, 0x00};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(0x42);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  resp[1] = SPI.transfer(0x00);
+
+  delayMicroseconds(4);
+
+  resp[2] = SPI.transfer(value);
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(resp, expected, 3);
+}
+
+bool OPCN2::set_laser_power(uint8_t value)
+{
+  // Set the laser power
+  // Value must be between 0-255
+  // Ex.
+  // $ alpha.set_laser_power(255);
+  byte resp[3];
+  byte expected[] = {0xF3, 0x42, 0x01};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(0x42);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  resp[1] = SPI.transfer(0x01);
+
+  delayMicroseconds(4);
+
+  resp[2] = SPI.transfer(value);
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(resp, expected, 3);
+}
+
+bool OPCN2::toggle_fan(bool state)
+{
+  // Toggle the state of the fan
+  // Ex.
+  // $ alpha.toggle_fan(true); // turns fan on
+  byte resp[2];
+  byte expected[] = {0xF3, 0x03};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(0x03);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  // turn either on or off
+  digitalWrite(this->_CS, LOW);
+  if (state == true){
+    resp[1] = SPI.transfer(0x04);
+  }
+  else {
+    resp[1] = SPI.transfer(0x05);
+  }
+
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(resp, expected, 2);
+}
+
+bool OPCN2::toggle_laser(bool state)
+{
+  // Toggle the state of the laser
+  // Ex.
+  // $ alpha.toggle_laser(true);
+  byte resp[2];
+  byte expected[] = {0xF3, 0x03};
+
+  digitalWrite(this->_CS, LOW);
+  resp[0] = SPI.transfer(0x03);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  if (state == true){
+    resp[1] = SPI.transfer(0x02);
+  }
+  else {
+    resp[1] = SPI.transfer(0x03);
+  }
+
+  digitalWrite(this->_CS, HIGH);
+
+  return this->_compare_arrays(resp, expected, 2);
+}
+
+struct ConfigVars OPCN2::read_configuration_variables()
+{
+  // Read the configuration variables and return the structure
+  // Ex.
+  // $ alpha.read_configuration_variables();
+  ConfigVars results;       // empty structure for the data
+  byte vals[256];
+
+  // Read the config variables
+  digitalWrite(this->_CS, LOW);
+  SPI.transfer(0x3c);
+  digitalWrite(this->_CS, HIGH);
+
+  delay(10);
+
+  digitalWrite(this->_CS, LOW);
+  for (int i = 0; i < 256; i++){
+    vals[i] = SPI.transfer(0x00);
+    delayMicroseconds(4);
+  }
+
+  digitalWrite(this->_CS, HIGH);
+
+  // Fill in the results
+  results.bb0 = this->_16bit_int(vals[0], vals[1]);
+  results.bb1 = this->_16bit_int(vals[2], vals[3]);
+  results.bb2 = this->_16bit_int(vals[4], vals[5]);
+  results.bb3 = this->_16bit_int(vals[6], vals[7]);
+  results.bb4 = this->_16bit_int(vals[8], vals[9]);
+  results.bb5 = this->_16bit_int(vals[10], vals[11]);
+  results.bb6 = this->_16bit_int(vals[12], vals[13]);
+  results.bb7 = this->_16bit_int(vals[14], vals[15]);
+  results.bb8 = this->_16bit_int(vals[16], vals[17]);
+  results.bb9 = this->_16bit_int(vals[18], vals[19]);
+  results.bb10 = this->_16bit_int(vals[20], vals[21]);
+  results.bb11 = this->_16bit_int(vals[22], vals[23]);
+  results.bb12 = this->_16bit_int(vals[24], vals[25]);
+  results.bb13 = this->_16bit_int(vals[26], vals[27]);
+  results.bb14 = this->_16bit_int(vals[28], vals[29]);
+
+  // Bin Particle Volumes
+  results.bpv0 = this->_calculate_float(vals[32], vals[33], vals[34], vals[35]);
+  results.bpv1 = this->_calculate_float(vals[36], vals[37], vals[38], vals[39]);
+  results.bpv2 = this->_calculate_float(vals[40], vals[41], vals[42], vals[43]);
+  results.bpv3 = this->_calculate_float(vals[44], vals[45], vals[46], vals[47]);
+  results.bpv4 = this->_calculate_float(vals[48], vals[49], vals[50], vals[51]);
+  results.bpv5 = this->_calculate_float(vals[52], vals[53], vals[54], vals[55]);
+  results.bpv6 = this->_calculate_float(vals[56], vals[57], vals[58], vals[59]);
+  results.bpv7 = this->_calculate_float(vals[60], vals[61], vals[62], vals[63]);
+  results.bpv8 = this->_calculate_float(vals[64], vals[65], vals[66], vals[67]);
+  results.bpv9 = this->_calculate_float(vals[68], vals[69], vals[70], vals[71]);
+  results.bpv10 = this->_calculate_float(vals[72], vals[73], vals[74], vals[75]);
+  results.bpv11 = this->_calculate_float(vals[76], vals[77], vals[78], vals[79]);
+  results.bpv12 = this->_calculate_float(vals[80], vals[81], vals[82], vals[83]);
+  results.bpv13 = this->_calculate_float(vals[84], vals[85], vals[86], vals[87]);
+  results.bpv14 = this->_calculate_float(vals[88], vals[89], vals[90], vals[91]);
+  results.bpv15 = this->_calculate_float(vals[92], vals[93], vals[94], vals[95]);
+
+  // Bin Particle Densities
+  results.bpd0 = this->_calculate_float(vals[96], vals[97], vals[98], vals[99]);
+  results.bpd1 = this->_calculate_float(vals[100], vals[101], vals[102], vals[103]);
+  results.bpd2 = this->_calculate_float(vals[104], vals[105], vals[106], vals[107]);
+  results.bpd3 = this->_calculate_float(vals[108], vals[109], vals[110], vals[111]);
+  results.bpd4 = this->_calculate_float(vals[112], vals[113], vals[114], vals[115]);
+  results.bpd5 = this->_calculate_float(vals[116], vals[117], vals[118], vals[119]);
+  results.bpd6 = this->_calculate_float(vals[120], vals[121], vals[122], vals[123]);
+  results.bpd7 = this->_calculate_float(vals[124], vals[125], vals[126], vals[127]);
+  results.bpd8 = this->_calculate_float(vals[128], vals[129], vals[130], vals[131]);
+  results.bpd9 = this->_calculate_float(vals[132], vals[133], vals[134], vals[135]);
+  results.bpd10 = this->_calculate_float(vals[136], vals[137], vals[138], vals[139]);
+  results.bpd11 = this->_calculate_float(vals[140], vals[141], vals[142], vals[143]);
+  results.bpd12 = this->_calculate_float(vals[144], vals[145], vals[146], vals[147]);
+  results.bpd13 = this->_calculate_float(vals[148], vals[149], vals[150], vals[151]);
+  results.bpd14 = this->_calculate_float(vals[152], vals[153], vals[154], vals[155]);
+  results.bpd15 = this->_calculate_float(vals[156], vals[157], vals[158], vals[159]);
+
+  // Bin Particle Sample Volumes
+  results.bsvw0 = this->_calculate_float(vals[160], vals[161], vals[162], vals[163]);
+  results.bsvw1 = this->_calculate_float(vals[164], vals[165], vals[166], vals[167]);
+  results.bsvw2 = this->_calculate_float(vals[168], vals[169], vals[170], vals[171]);
+  results.bsvw3 = this->_calculate_float(vals[172], vals[173], vals[174], vals[175]);
+  results.bsvw4 = this->_calculate_float(vals[176], vals[177], vals[178], vals[179]);
+  results.bsvw5 = this->_calculate_float(vals[180], vals[181], vals[182], vals[183]);
+  results.bsvw6 = this->_calculate_float(vals[184], vals[185], vals[186], vals[187]);
+  results.bsvw7 = this->_calculate_float(vals[188], vals[189], vals[190], vals[191]);
+  results.bsvw8 = this->_calculate_float(vals[192], vals[193], vals[194], vals[195]);
+  results.bsvw9 = this->_calculate_float(vals[196], vals[197], vals[198], vals[199]);
+  results.bsvw10 = this->_calculate_float(vals[200], vals[201], vals[202], vals[203]);
+  results.bsvw11 = this->_calculate_float(vals[204], vals[205], vals[206], vals[207]);
+  results.bsvw12 = this->_calculate_float(vals[208], vals[209], vals[210], vals[211]);
+  results.bsvw13 = this->_calculate_float(vals[212], vals[213], vals[214], vals[215]);
+  results.bsvw14 = this->_calculate_float(vals[216], vals[217], vals[218], vals[219]);
+  results.bsvw15 = this->_calculate_float(vals[220], vals[221], vals[222], vals[223]);
+
+  // Gain Scaling Coefficient
+  results.gsc = this->_calculate_float(vals[224], vals[225], vals[226], vals[227]);
+
+  // Sample Flow Rate (ml/s)
+  results.sfr = this->_calculate_float(vals[228], vals[229], vals[230], vals[231]);
+
+  // LaserDAC
+  results.laser_dac = (unsigned int)vals[232];
+  results.fan_dac = (unsigned int)vals[233];
+
+  // Time-of-Flight to Sample Flow Rate ratio
+  results.tof_sfr = (unsigned int)vals[234];
+
+  return results;
+}
+
+struct ConfigVars2 OPCN2::read_configuration_variables2()
+{
+  // Read the additional configuration variables
+  // Only available on OPCN2's with firmware >v18
+  // Ex.
+  // $ alpha.read_configuration_variables2();
+  ConfigVars2 results;       // empty structure for the data
+  byte vals[9];
+
+  if (this->firm_ver.major < 18) {
+    results.AMSamplingInterval    = -999;
+    results.AMIntervalCount       = -999;
+    results.AMFanOnIdle           = -999;
+    results.AMLaserOnIdle         = -999;
+    results.AMMaxDataArraysInFile = -999;
+    results.AMOnlySavePMData      = -999;
+  }
+  else {
+    // Read the config variables
+    digitalWrite(this->_CS, LOW);
+    SPI.transfer(0x3D);
+    digitalWrite(this->_CS, HIGH);
+
+    delay(10);
+
+    digitalWrite(this->_CS, LOW);
+    for (int i = 0; i < 9; i++){
+        vals[i] = SPI.transfer(0x00);
+        delayMicroseconds(4);
+    }
+
+    digitalWrite(this->_CS, HIGH);
+
+    // Fill in the results
+    results.AMSamplingInterval    = this->_16bit_int(vals[0], vals[1]);
+    results.AMIntervalCount       = this->_16bit_int(vals[2], vals[3]);
+    results.AMFanOnIdle           = (unsigned int)vals[4];
+    results.AMLaserOnIdle         = (unsigned int)vals[5];
+    results.AMMaxDataArraysInFile = this->_16bit_int(vals[6], vals[7]);
+    results.AMOnlySavePMData      = (unsigned int)vals[8];
+  }
+
+  return results;
+}
+
+String OPCN2::read_serial_number()
+{
+  // Read the serial number of the OPC
+  // Only available on OPCN2's with firmware >v18
+  // Ex.
+  // $ alpha.read_serial_number();
+  String result = "";
+  byte vals[60];
+
+  if (this->firm_ver.major < 18) {
+    result = "";
+  }
+  else {
+    digitalWrite(this->_CS, LOW);       // Pull the CS low
+    SPI.transfer(0x10);                 // Send the start command
+    digitalWrite(this->_CS, HIGH);       // Pull the CS High
+
+    delay(3);
+
+    // Iterate to read the entire string
+    digitalWrite(this->_CS, LOW);
+    for (int i = 0; i < 61; i++){
+        vals[i] = SPI.transfer(0x00);
+        result += String((char)vals[i]);
+        delayMicroseconds(4);
+    }
+
+    digitalWrite(this->_CS, HIGH);
+  }
+
+  result = result.trim();
+
+  return result;
+}
+
+struct PMData OPCN2::read_pm_data()
+{
+  // Read the PM Data and reset the histogram, return the struct
+  // Only available on OPCN2's with firmware >v18
+  // Ex.
+  // $ alpha.read_pm_data();
+  PMData data;
+  byte vals[12];
+
+  if (this->firm_ver.major < 18) {
+      data.pm1  = -999;
+      data.pm25 = -999;
+      data.pm10 = -999;
+  }
+  else {
+      // Read the data and clear the local memory
+      digitalWrite(this->_CS, LOW);       // Pull the CS Low
+      SPI.transfer(0x32);                 // Transfer the command byte
+      digitalWrite(this->_CS, HIGH);
+
+      delay(12);                          // Delay for 12 ms
+
+      // Send commands and build array of data
+      digitalWrite(this->_CS, LOW);
+
+      for (int i = 0; i < 12; i++){
+          vals[i] = SPI.transfer(0x00);
+          delayMicroseconds(4);
+      }
+
+      digitalWrite(this->_CS, HIGH);      // Pull the CS High
+
+      data.pm1  = this->_calculate_float(vals[0], vals[1], vals[2], vals[3]);
+      data.pm25 = this->_calculate_float(vals[4], vals[5], vals[6], vals[7]);
+      data.pm10 = this->_calculate_float(vals[8], vals[9], vals[10], vals[11]);
+  }
+
+  return data;
+}
+
+struct HistogramData OPCN2::read_histogram(bool convert_to_conc)
+{
+  // Read the Histogram Data and reset the histogram, return the struct
+  // convert_to_conc can be set to true if you would like the result
+  // returned as concentrations (rather than raw counts) with units of
+  // particles per cubic centimeter [#/cc]
+  // Ex.
+  // $ alpha.read_histogram(true)
+  HistogramData data;
+  byte vals[62];
+
+  // Read the data and clear the local memory
+  digitalWrite(this->_CS, LOW);       // Pull the CS Low
+  SPI.transfer(0x30);                 // Transfer the command byte
+  digitalWrite(this->_CS, HIGH);
+
+  delay(12);                          // Delay for 12 ms
+
+  // Send commands and build array of data
+  digitalWrite(this->_CS, LOW);
+
+  for (int i = 0; i < 62; i++){
+      vals[i] = SPI.transfer(0x00);
+      delayMicroseconds(4);
+  }
+
+  digitalWrite(this->_CS, HIGH);      // Pull the CS High
+
+  data.period = this->_calculate_float(vals[44], vals[45], vals[46], vals[47]);
+  data.sfr    = this->_calculate_float(vals[36], vals[37], vals[38], vals[39]);
+
+  // If convert_to_conc = True, convert from raw data to concentration
+  double conv;
+
+  if ( convert_to_conc != true ) {
+      conv = 1.0;
+  }
+  else {
+      conv = data.sfr * data.period;
+  }
+
+  // Calculate all of the values!
+  data.bin0   = this->_16bit_int(vals[0], vals[1]) / conv;
+  data.bin1   = this->_16bit_int(vals[2], vals[3]) / conv;
+  data.bin2   = this->_16bit_int(vals[4], vals[5]) / conv;
+  data.bin3   = this->_16bit_int(vals[6], vals[7]) / conv;
+  data.bin4   = this->_16bit_int(vals[8], vals[9]) / conv;
+  data.bin5   = this->_16bit_int(vals[10], vals[11]) / conv;
+  data.bin6   = this->_16bit_int(vals[12], vals[13]) / conv;
+  data.bin7   = this->_16bit_int(vals[14], vals[15]) / conv;
+  data.bin8   = this->_16bit_int(vals[16], vals[17]) / conv;
+  data.bin9   = this->_16bit_int(vals[18], vals[19]) / conv;
+  data.bin10  = this->_16bit_int(vals[20], vals[21]) / conv;
+  data.bin11  = this->_16bit_int(vals[22], vals[23]) / conv;
+  data.bin12  = this->_16bit_int(vals[24], vals[25]) / conv;
+  data.bin13  = this->_16bit_int(vals[26], vals[27]) / conv;
+  data.bin14  = this->_16bit_int(vals[28], vals[29]) / conv;
+  data.bin15  = this->_16bit_int(vals[30], vals[31]) / conv;
+
+  data.bin1MToF = int(vals[32]) / 3.0;
+  data.bin3MToF = int(vals[33]) / 3.0;
+  data.bin5MToF = int(vals[34]) / 3.0;
+  data.bin7MToF = int(vals[35]) / 3.0;
+
+  // This holds either temperature or pressure
+  // If temp, this is temp in C x 10
+  // If pressure, this is pressure in Pa
+  data.temp_pressure = this->_32bit_int(vals[40], vals[41], vals[42], vals[43]);
+
+  data.checksum = this->_16bit_int(vals[48], vals[49]);
+
+  data.pm1 = this->_calculate_float(vals[50], vals[51], vals[52], vals[53]);
+  data.pm25 = this->_calculate_float(vals[54], vals[55], vals[56], vals[57]);
+  data.pm10 = this->_calculate_float(vals[58], vals[59], vals[60], vals[61]);
+
+  return data;
+}
diff --git a/firmware/opcn2.h b/src/opcn2.h
similarity index 98%
rename from firmware/opcn2.h
rename to src/opcn2.h
index b3b6873..03f4ad9 100644
--- a/firmware/opcn2.h
+++ b/src/opcn2.h
@@ -204,7 +204,7 @@ class OPCN2
     ConfigVars read_configuration_variables();
     ConfigVars2 read_configuration_variables2();
     PMData read_pm_data();
-    HistogramData read_histogram(bool convert_to_conc);
+    HistogramData read_histogram(bool convert_to_conc = true);
 };
 
 #endif