keyhole-comm 1.15.0

Low-effort serial/pipe communication, e.g. for talking to devices that use the Arduino-IDE Keyhole library, or to other processes via stdin/stdout

This module provides the Keyhole class, which allows easy line-by-line text communication over a serial port, or through a stdin/stdout pipe. It is particularly useful for implementing the computer’s side of the interaction when talking to a microcontroller that has been programmed using the Arduino-IDE Keyhole library. In that case, exposed sketch variables can be accessed as attributes of a Keyhole instance in Python.

The Arduino side:

#include "Keyhole.h"
Keyhole k;

void setup()
{
    Serial.begin(9600);
}
void loop()
{
    static float foo = 1.23;
    static String bar = "hello";

    // insert main sketch logic here (use foo and bar to do whatever is so important)

    if(k.begin()) // expose the variables
    {
        k.variable("foo", foo);
        k.variable("bar", bar);
        k.end();
    }
}

The Python side:

from keyhole import Keyhole

# k = Keyhole('COM4')                 # windows example
k = Keyhole('/dev/cu.usbmodem[0-9]*') # macos example (globbing is OK if the match is unique)

print( k.bar ) # queries an exposed sketch variable
k.foo = 4.56   # assigns to an exposed sketch variable and makes the .variable() call return true

print( k() )  # get all exposed variables

In Python, you can also communicate similarly with a process on the local computer, exchanging messages in the same format over stdin/stdout. To do this, initialize your Keyhole instance via the pipe argument instead of the port argument:

from keyhole import Keyhole

k = Keyhole( pipe='python -m keyhole.pipe' ) # running the `keyhole.pipe` submodule
                                             # provides a toy example
print( k.spam )
k.eggs = 12
print( k() )