sensors

Simple micropython libraries for various sensors

distance.py

Simple library which used for HC-SR04 ultrasonic distance sensor and Sharp GP2Y0A21YK (10-80cm range) infrared distance sensor. Source file: distance.py

WARNING: The Sharp infrared distance sensor can return a voltage as high as 2.6V above the maximum allowable input voltage for the AD pin on the ESP8266 (1V). This applies to all separate modules like ESP-12, ESP-07 and similar that do not have a onboard resistor voltage divider at the AD input. In this case a resistor divider with values of 220kohm and 100kohm should be used.

---

class hcsr04

---

Initialise pins used by sensor

hcsr04.init(echo_pin, trig_pin)

parameters:

• echo_pin - sensor ECHO pin
• trig_pin - sensor TRIGGER pin

---

Read measured distance in centimeters from sensor

hcsr04.distance_cm()

parameters: none

---

Read measured distance in meters from sensor

hcsr04.distance_m()

parameters: none

---

class sharp1080

---

Initialise sensor pin and reading board type. In case of ESP8266 pin number may be any number. It has only one AD input pin

sharp1080.init(pin, model)

Parameters:

• pin - number of pin connected to sensor.
• model - model type of board. Avialable values

1 or sharp1080.ESP8266 for esp 8266

2 or sharp1080.ESP32 for esp 32

3 or sharp1080.PICO for Raspberry Pi Pico

---

Read measured distance in centimeters from sensor.

sharp1080.distance_cm()

Parameters: none

---

Read measured distance in meters from sensor.

sharp1080.distance_m()

Parameters: none

---

example

# INFRARED SENSOR
# import library
from distance import sharp1080 as dist
# esp8266 case init
dist.init(0, dist.ESP8266)
# esp32 case init
dist.init(36, dist.ESP32)
# raspberry pi pico case init
dist.init(26, dist.PICO)
# read measured distance
print(dist.distance_cm())

---

# ULTRASONIC SENSOR
# import library
from distance import hcsr04 as dist
# init sensor
dist.init(4, 5)
# measure distance
print(dist.distance_m())

dallas.py

A simple library to support the dallas ds1820 and ds18b20 temperature sensor. Only conversion and temperature reading for one sensor per pin is implemented. Communication with the sensor is done bypassing the sensor address. Parasite power mode is not implemented. Source file: dallas.py

ds1820

Class for ds1820 temperature sensor with 9 bit resolution (temperature changes by 0.5°C).

---

class ds1820

---

Initialise and configure pins used by sensor.

dallas.ds1820.init(pin)

parameters:

• pin - sensor DQ pin

---

Send convert command to begin measure temperature

dallas.ds1820.convert(pin)

parameters:

• pin - sensor DQ pin

---

Send read command to read measurement temperature

dallas.ds1820.read(pin)

parameters:

• pin - sensor DQ pin

---

ds18b20

Class for ds18b20 temperature sensor with 12 bit resolution (temperature changes by 0.0625°C).

---

class ds18b20

---

Initialise and configure pins used by sensor.

dallas.ds18b20.init(pin)

parameters:

• pin - sensor DQ pin

---

Send convert command to begin measure temperature

dallas.ds18b20.convert(pin)

parameters:

• pin - sensor DQ pin

---

Send read command to read measurement temperature

dallas.ds18b20.read(pin)

parameters:

• pin - sensor DQ pin

---

example

# model ds18b20
import time
from dallas import ds18b20 as ds
ds.init(4)
ds.convert(4)
# wait 750ms to end of measure temperature
time.sleep(0.75)
print("temperature: " + str(ds.read(4)))