feat: new module for interacting with Raspberry Pi GPIO outputs

src/python/otsim/rpi_gpio/rpi_gpio.py

@@ -0,0 +1,100 @@
+from __future__ import annotations
+
+import json, logging, signal, sys, threading, typing
+
+import otsim.msgbus.envelope as envelope
+import xml.etree.ElementTree as ET
+
+from otsim.msgbus.envelope   import Envelope
+from otsim.msgbus.subscriber import Subscriber
+
+import RPi.GPIO as GPIO
+
+
+class RPiGPIO:
+  def __init__(self: RPiGPIO, pub: str, pull: str, el: ET.Element):
+    # map tags --> pin number
+    self.outputs: typing.Dict[str, int] = {}
+
+    self.name = el.get('name', default='ot-sim-rpi-gpio')
+    mode      = el.get('mode', default='BOARD')
+
+    if mode.upper() == 'BOARD':
+      GPIO.setmode(GPIO.BOARD)
+    elif mode.upper() == 'BCM':
+      GPIO.setmode(GPIO.BCM)
+    else:
+      print(f"unknown GPIO mode '{mode}' - defaulting to 'BOARD' mode")
+      GPIO.setmode(GPIO.BOARD)
+
+    pub_endpoint    = el.findtext('pub-endpoint', default=pub)
+    self.subscriber = Subscriber(pub_endpoint)
+
+    for o in el.findall('output'):
+      pin = int(o.get('pin'))
+      tag = o.findtext('tag')
+
+      self.outputs[tag] = pin
+      GPIO.setup(pin, GPIO.OUT)
+
+    self.subscriber.add_update_handler(self.handle_msgbus_update)
+
+
+  def start(self: RPiGPIO):
+    self.subscriber.start('RUNTIME')
+
+
+  def stop(self: RPiGPIO):
+    self.subscriber.stop()
+
+
+  def handle_msgbus_update(self: RPiGPIO, env: Envelope):
+    update = envelope.update_from_envelope(env)
+
+    if update:
+      for point in update['updates']:
+        tag = point['tag']
+
+        if tag in self.outputs:
+          GPIO.output(self.outputs[tag], point['value'])
+
+
+def main():
+  logging.basicConfig(level=logging.ERROR)
+
+  if len(sys.argv) < 2:
+    print('no config file provided')
+    sys.exit(1)
+
+  tree = ET.parse(sys.argv[1])
+
+  root = tree.getroot()
+  assert root.tag == 'ot-sim'
+
+  mb = root.find('message-bus')
+
+  if mb:
+    pub  = mb.findtext('pub-endpoint')
+    pull = mb.findtext('pull-endpoint')
+  else:
+    pub  = 'tcp://127.0.0.1:5678'
+    pull = 'tcp://127.0.0.1:1234'
+
+  devices: typing.List[RPiGPIO] = []
+
+  for gpio in root.findall('rpi-gpio'):
+    device = RPiGPIO(pub, pull, gpio)
+    device.start()
+
+    devices.append(device)
+
+  waiter = threading.Event()
+
+  def handler(*_):
+    waiter.set()
+
+  signal.signal(signal.SIGINT, handler)
+  waiter.wait()
+
+  for device in devices:
+    device.stop()

src/python/setup.py

@@ -8,13 +8,15 @@
   'pandas',
   'pyzmq',
   'requests',
+  'RPi.GPIO',
   'windpowerlib',
 ]
 
 ENTRIES = {
   'console_scripts' : [
     'ot-sim-ground-truth-module = otsim.ground_truth.ground_truth:main',
     'ot-sim-io-module = otsim.io.io:main',
+    'ot-sim-rpi-gpio-module = otsim.rpi_gpio.rpi_gpio:main',
     'ot-sim-wind-turbine-anemometer-module = otsim.wind_turbine.anemometer.anemometer:main',
     'ot-sim-wind-turbine-power-output-module = otsim.wind_turbine.power_output.power_output:main',
   ]