Controller Remote Access Protocol (CRAP)

Kotlin multiplatform client library used to do remote procedure calls (RPC) to microcontrollers.

Features

• Arduino Uno support
  • USB serial communication
    • Minimal bytes are transferred
    • Fast sketch flow control. Uses array of lambdas instead of if-else-switch-cases.
    • Sketch uses 45 % of storage and 37 % of memory on Uno.
    • jSerialComm JVM implementation.
• Arduino Relay Shield support
• 1-wire support with following devices:
  • Dallas Digital Temperature Sensor e.g. DS18B20
• Basic actuators: switch, relay

Examples

Examples are located at src/jvmTest/kotlin/arduino directory.

Blink

fun main() = Uno(1)                    // Connects Arduino Uno on 2nd serial.
        .setup { led.output() }        // Sets built-in LED pin to output mode.
        .loop { led.high = !led.high } // Changes its state on every second (by default).

Switch

fun main() = Uno("COM3").setup {          // Uno is on COM3.
    switch(d3).onChange {                 // Attaches switch to pin 3.
        println("Switch changed to $it.") // Prints every state changes.
    }
}()                                       // Start's the loop

Dallas Temperature Sensor

fun main() = Uno().setup {                         // Connects default port.
    dallasTemperature().onChange {                 // Set up 1-wire on first free pin (D2)
            old, new -> println("$old -> $new °C") // Prints when temperature changes.
    }
}()

Relays

fun main() = object : Uno(1) {                       // Uno can also be extended.
    val relays = relayShield().relays                // Attaches 4 relay shield.
    override fun loop() { relays.random().change() } // Change state on random relay.
}()                                                  // Start's the loop

Roadmap / Limitations

• Better logging.
• Packages aren't published to Maven Central yet.
• Interrupt Service Routines can't be used, because they leave the connection in asynchronous state (now) and procedure pool is quite full.
• Interrupts can't be disabled because they don't compile inside lambda.

How to use

1. Clone this repository using git clone https://github.com/jpink/crap.git.
2. Publish it to your local Maven using ./gradlew publishToMavenLocal.
3. Edit your project's build.gradle.kts file:
   1. Add mavenLocal() to your repositories.
   2. Add implementation("fi.papinkivi:crap:2.1.0") to your main or jvmMain dependencies.
4. Install Arduino IDE.
   1. Ensure that OneWire and DallasTemperature libraries are installed.
   2. Open src/assembly/Uno3/Uno3.ino sketch and upload it to your microcontroller.