Dear Andrew, no problems at all, sorry and sad for those wild fires, worst ever I think? Terrible, really.
I took some time to write a small python script that you can test when time and if you like. It is rather straight forward, it connects to a mqtt broker (I assumed in the same Pi, otherwise you have to edit the ip). It loads the pifacecad python library, writes a welcome message to the lcd. When you press a button you should see it's number on the lcd and receive a mqtt message in Node-RED
To make it happen:
- install the pifacecad python library, see here http://piface.github.io/pifacecad/installation.html
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install python{,3}-pifacecad
- Install paho mqtt client (if you do not have it already)
sudo pip install paho-mqtt
- Create a new file piFaceCAD.py in /home/pi/ with the following content (and change ip if necessary)
# coding: utf-8
import pifacecad
import time
import paho.mqtt.client as mqtt
def update_pin_text(event):
event.chip.lcd.set_cursor(13, 0)
event.chip.lcd.write(str(event.pin_num))
send_mqtt_message("pifacecad", "You pressed button:"+str(event.pin_num))
def send_mqtt_message(topic, msg):
for i in range(5):
try:
result, mid = client.publish(topic, msg, 0)
#print ('result', result)
if result == 0:
break
except:
print ("retrying...")
def on_connect(client, obj, flags, rc):
client.subscribe("cmds", 0)
def on_subscribe(client, userdata, mid, granted_qos):
print ('Subscribed:', userdata, mid, granted_qos)
print ('We are here, waiting for commands...')
def on_message(mosq, obj, msg):
global abort
try:
event = msg.payload.decode("utf-8").split('.')
#print (event)
if event[0] == 'abort':
listener.deactivate()
abort = True
except:
pass
abort = False
client = mqtt.Mosquitto()
client.on_connect = on_connect
client.on_message = on_message
client.on_subscribe = on_subscribe
client.connect("127.0.0.1", 1883, 60)
client.loop_start()
cad = pifacecad.PiFaceCAD()
cad.lcd.write("Welcome to your piFaceCAD! You pressed: ")
listener = pifacecad.SwitchEventListener(chip=cad)
for i in range(8):
listener.register(i, pifacecad.IODIR_FALLING_EDGE, update_pin_text)
listener.activate()
while not abort:
time.sleep(0.5)
client.loop_stop()
client.disconnect()
del client
exit(0)
To try it out, you can import/use the following flow. To start or abort the script, just click on the buttons. To make it "visible" the script is started on the display nbr 0. I hope it works (not able to test with the piface), if so, you should see the messages in the NR debug window
[{"id":"d4ed32d4.b091a","type":"exec","z":"ae89c6f4.025a58","command":"export DISPLAY=:0 && lxterminal -e python /home/pi/piFaceCAD.py","addpay":false,"append":"","useSpawn":"false","timer":"","oldrc":false,"name":"","x":700,"y":100,"wires":[[],[],[]]},{"id":"e5597030.9c372","type":"inject","z":"ae89c6f4.025a58","name":"Start script","topic":"","payload":"true","payloadType":"bool","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":250,"y":100,"wires":[["d4ed32d4.b091a"]]},{"id":"9f5a12c4.c3359","type":"inject","z":"ae89c6f4.025a58","name":"Abort script","topic":"","payload":"abort","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":260,"y":180,"wires":[["2b2c9050.0d932"]]},{"id":"2b2c9050.0d932","type":"mqtt out","z":"ae89c6f4.025a58","name":"","topic":"cmds","qos":"","retain":"","broker":"75eba16c.094f9","x":500,"y":180,"wires":[]},{"id":"d1ff0302.d0d1a","type":"mqtt in","z":"ae89c6f4.025a58","name":"","topic":"pifacecad","qos":"0","datatype":"auto","broker":"75eba16c.094f9","x":250,"y":260,"wires":[["e16edbaf.068c18"]]},{"id":"e16edbaf.068c18","type":"debug","z":"ae89c6f4.025a58","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":520,"y":260,"wires":[]},{"id":"75eba16c.094f9","type":"mqtt-broker","z":"","name":"","broker":"127.0.0.1","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]
