HomeServerIOExt/ioext/ioext.py

#!/usr/bin/python3 -u
#
import serial
from time import sleep
import os
import sys
import paho.mqtt.client as mqtt
import json

# --- CONFIGURATION ---

# timeout in s to end script when nothing is received (will be restarted by systemd then)
# must be higher than getStatusInterval 
quitOnNoReceiveTimeout = 75

# status file - on ramdrive (/tmp on RasPi by default)
# is "touched" every time a serial message comes in so that working communication can be monitored easily
statusFile = '/tmp/ioext_running'

# serial port config
serialPort = '/dev/serial/by-id/usb-1a86_USB_Serial-if00-port0'
serialBaud = 57600
serialTimeout = 1 # should be 1 as above interval/timeout relies on it

# MQTT config
mqtt_server = "mqtt.lan"
mqtt_port = 1883
mqtt_user = "user"
mqtt_password = "password"

mqtt_base_topic = "T5/HomeSvrIOExt"

mqtt_topic_tuerkontakt = "T5/Wohnungstuer/Tuerkontakt"
mqtt_topic_pir1 = "T5/VZ/PIR1"
mqtt_topic_pir2 = "T5/VZ/PIR2"
mqtt_topic_out_temp = "T5/Abstr/Sensors/temp"
mqtt_topic_out_hum = "T5/Abstr/Sensors/hum"

# --- END CONFIGURATION ---



# --- GLOBAL VARS ---
noReceiveCount = 0  # increase everytime the serial readline times out (1s timeout)
#getStatusCount = 0  # used as heartbeat, get status every 30s
verbose = False
debug = False
quiet = True


lastState_tk = None
lastState_pir1 = None
lastState_pir2 = None

# --- END GLOBAL VARS ---

if len(sys.argv) >= 2:
    if sys.argv[1] == "-q":
        verbose = False
        debug = False
        quiet = True
        #print("VERBOSE=ON")
    elif sys.argv[1] == "-v":
        verbose = True
        debug = False
        quiet = False
        #print("VERBOSE=ON")
    elif sys.argv[1] == "-d":
        verbose = True
        quiet = False
        debug = True
        #print("DEBUG=ON")


def on_connect(client, userdata, flags, rc):
    if not quiet:
        print("MQTT connected with result code " + str(rc))
    #client.subscribe(mqtt_topic_cmd)
    
#def on_message(client, userdata, msg):    
#    if msg.topic == mqtt_topic_cmd:
#        payload = msg.payload.decode('ascii')
#        if payload == "status" or payload == "get conf" or payload == "clear" or payload == "open door" or payload.startswith("set prof ") or payload.startswith("set conf "):
#            if verbose:
#                print("serCmd: " + payload)
#            serCmd = payload + '\n'
#            ser.write(serCmd.encode('ascii'))
#        elif verbose:
#            print("unknown command:", payload)

def touch(fname, times=None):
    with open(fname, 'a'):
        os.utime(fname, times)

mqttc = mqtt.Client()
mqttc.on_connect = on_connect
#mqttc.on_disconnect = on_disconnect
#mqttc.on_message = on_message

mqttc.username_pw_set(mqtt_user, mqtt_password)
mqttc.connect(mqtt_server, mqtt_port, 60)

mqttc.loop_start()

ser = serial.Serial(port=serialPort,
    baudrate = serialBaud,
    parity=serial.PARITY_NONE,
    stopbits=serial.STOPBITS_ONE,
    bytesize=serial.EIGHTBITS,
    timeout=serialTimeout)
    


try:
    while True:
        ##ser.flushInput()        ## attention truncates incoming strings if there is little time between them 
        #read buffer until cr/lf
        serLine = ser.readline().strip()
        # catch exception on invalid char coming in: UnicodeDecodeError: 'ascii' codec can't decode byte 0xf4 in position 6: ordinal not in range(128)
        try: 
            serLine = serLine.decode('ascii')
        except:
            serLine = ""
        
        # if there came something in...
        if(serLine):
            noReceiveCount = 0
            touch(statusFile)
            #serLine = serLine.strip('\'')
            #serLine = serLine.strip('\r')
            #serLine = serLine.strip('\n')
            if verbose:
                print ('RX: ' + repr(serLine))    #Echo the serial buffer bytes up to the CRLF back to screen
            mqttc.publish(mqtt_base_topic + "/RX", str(serLine), qos=0, retain=False)
            
            # Tuerkontakt
            if serLine.startswith('P2='):
                newState = None
                if serLine == "P2=L":
                    newState = "OFF"
                elif serLine == "P2=H":
                    newState = "ON"
                    
                if newState is not None and lastState_tk != newState:
                    lastState_tk = newState
                    mqttc.publish(mqtt_topic_tuerkontakt, newState, qos=0, retain=False)
                    
            # PIR #1
            if serLine.startswith('P3='):
                newState = None
                if serLine == "P3=L":
                    newState = "OFF"
                elif serLine == "P3=H":
                    newState = "ON"
                    
                if newState is not None and lastState_pir1 != newState:
                    lastState_pir1 = newState
                    mqttc.publish(mqtt_topic_pir1, newState, qos=0, retain=False)
            
            # PIR #2
            if serLine.startswith('P4='):
                newState = None
                if serLine == "P4=L":
                    newState = "OFF"
                elif serLine == "P4=H":
                    newState = "ON"
                
                if newState is not None and lastState_pir2 != newState:
                    lastState_pir2 = newState
                    mqttc.publish(mqtt_topic_pir2, newState, qos=0, retain=False)
                   
            # DHT TH sensor
            # {"T":26.60,"H":36}
            if serLine.startswith('{"T":'):
                th = json.loads(serLine)
                t = round(float(th["T"]), 1)
                h = int(th["H"])
                if t >= -20 and t <= 50:
                    mqttc.publish(mqtt_topic_out_temp, str(t), qos=0, retain=False)
                if h >= 0 and h <= 100:
                    mqttc.publish(mqtt_topic_out_hum, str(h), qos=0, retain=False)
                
            
            ## publish MQTT messages
            #if serLine.startswith('EVENT_'):
            #    mqttc.publish(mqtt_topic_event, serLine, qos=0, retain=False)
            #    #os.system(os.path.dirname(os.path.realpath(__file__))+'/event_top5_klingel.py')
            #
            #elif serLine.startswith('OK'):
            #    mqttc.publish(mqtt_topic_cmdresponse, serLine, qos=0, retain=False)
            #    
            #elif serLine.startswith('{"'):
            #    mqttc.publish(mqtt_topic_cmdresponse, serLine, qos=0, retain=False)
            #    #os.system(os.path.dirname(os.path.realpath(__file__))+'/event_top5_klingel.py')
                
        # nothing came in this time...
        else:
            noReceiveCount += 1
            if debug:
                print("noReceiveCount=" + str(noReceiveCount))
            
            # quit script if nothing has been received for some time - will be restarted by systemd
            if noReceiveCount >= quitOnNoReceiveTimeout:
                quit()
            
        
        ## get status every [getStatusInterval] seconds
        #getStatusCount += 1
        #if getStatusCount >= getStatusInterval:
        #    getStatusCount = 0
        #    serCmd = 'status\n'
        #    ser.write(serCmd.encode('ascii'))
        #if debug:
        #    print("getStatusCount=" + str(getStatusCount))

            
except KeyboardInterrupt:
    print('\n')