serialOM.py : easy ObjectModel access for Python and microPython

EasyTarget

Hi all; this is something I have been working on to power my PrintEYE replacement but it took on a life of it's own and I'd like to get it out of my system.. so here goes.

serialOM.py is a self-contained python class that connects to the OM on a RRF device via USB or UART, and provides a local copy of the OM that can be periodically updated.

https://github.com/easytarget/serialOM

The readme there does a proper TL;DR but the highlights are:

Python3/microPython cross-compatible with both PySerial and the mpy UART support
Keys to be fetched can be specified on a per-mode basis and the 'seqs' key is used to only do verbose fetches when needed.
Controller reboots and mode changes are handled appropriately. soft failures (timeouts) are tolerated and detectable. Hard (comms port) errors trigger a custom exception.
more.. see readme.

Basic use can be as simple as:

from serialOM import serialOM
from serial import Serial

rrf = Serial('/dev/ttyACM0',57600)
OM  = serialOM(rrf, {'FFF':[],'CNC':[],'Laser':[]}, quiet=True)
print('state: ' + OM.model['state']['status']
     + ', up: ' + str(OM.model['state']['upTime']) + 's')

There is an associated printPy program that implements a robust logging / console info loop. It reconnects as USB ports change etc. and logs human-readable print/CNC/Laser status, value and progress data to the console and an optional file.

I consider the CPython side of this 'done' (unless bugs.. quite likely because I'm no Pythonista), it runs well from a Pi3 with a USB connection to my Duet2 WiFi.

There is a work in progress microPython version of this loop; printMPy which can do the same console output, but also has RGB 'mood/activity' light control and button/status controls being implemented.

Both of the print*Py loops use a separate output class. currently the same 'TXT' demo works on both. This is a template for my in-progress I2C output class can be run in a thread to allow screen animations independent of the serial comms.

T3P3Tony

@EasyTarget thanks for posting this here and sharing the code with the community!

berniej

@EasyTarget This is really useful tool! Thank you!

EasyTarget

@berniej Thankyou! I'm glad if this is useful for others.

Please note that I have just done some tweaks to the response reading and sequence processing that address a couple of concerns I had, it should be less liable to briefly de-syncing when console (or json) status messages arrive.

There is a new release, v1.1.0 in the repo, the changes are all internal, usage has not changed.

Finally; I got to do some gc.mem_free() data gathering at various points in the loop under micropython; I max out at about 24K total additional RAM consumed by the serialOM loop; even when I have cycled the controller through three modes and run a simulation in each to fully populate the local OM with typical data.
I'm pretty happy with this, better than I expected.

EasyTarget

A quick note that I just published a small update as release: v1.2.0

This removes the need to have a the separate compatLib.py library present; all the cross-python handling is now done in serialOM.py itself. Nothing else is changed.