ikea_vindriktning_pico_v1.py

# MicroPython code for the Raspberry Pi Pico to read the Ikea Vindriktning
# PM1006 Air Quality Sensor
# http://www.jdscompany.co.kr/download.asp?gubun=07&filename=PM1006_LED_PARTICLE_SENSOR_MODULE_SPECIFICATIONS.pdf
#
# Signal    PM1006      Pico
#  +5V       +5V         VSYS
#   GND      GND         GND
#   TX       REST        GP1 (UART0 RX)


# NOTE: Please add a favicon.ico to the root of the raspberry Pi if you want an Icon shown for the web interface

import _thread
import network
import socket
import time
from machine import Pin
from machine import UART

threadlocker = _thread.allocate_lock()

vindriktning_readings = "none available"

# vindriktning - data bit: 8, Stop bit: 1, Check bit: none, Baud rate: 9600bps 
uart0 = UART(0, baudrate=9600, tx=Pin(0), rx=Pin(1))

# WIFI Setup
ssid = "mySSID"
password = "mySecurePa33w0rd"

def vindriktning_validpacket(data):
    validpacket = True
    if not data: # Packet is none - just exit
        validpacket = False
    elif len(data) != 20:  # Packet must be 20 bytes long
        print(f"WARNING: Invalid PM1006 Packet Length of {len(data)}")
        validpacket = False
    elif not vindriktning_checksum(data):
        print(f"WARNING: PM1006 Checksum Invalid")
        validpacket = False
    elif not vindriktning_headerok(data):
        print(f"WARNING: PM1006 Header Does not match")
        validpacket = False
    return validpacket

def vindriktning_headerok(d):
    # First 3 Bytes must be 0x16,0x11,0x0b
    headerValid = (d[0] == 0x16 and d[1] == 0x11 and d[2] == 0x0B)
    return headerValid

def vindriktning_checksum(data):
    # Last byte is the checksum of the previous 19 bytes
    cs = 0
    for x in range (len(data) - 1):
        cs += data[x]
        if cs > 256:
            cs = cs - 256
    cs_ok = ((256 - cs) == data[19])
    # if not cs_ok:
    #     print(f"Calculated Checksum = {cs}, data checksum = {data[19]}")
    #     print(f"DATA={str(data)}")
    return cs_ok

def vindriktning_decode(data):
    json_pm = {}
    # json_pm['pm010'] = int((data[9] << 8) | data[10]) / 10  # Not officially supported
    json_pm['pm025'] = int((data[5] << 8) | data[6]) / 10
    # json_pm['pm100'] = int((data[13] << 8) | data[14]) / 10  # Not officially supported
    json_pm['status'] = vindriktning_trafficlights(json_pm['pm025'])
    return json_pm

def vindriktning_trafficlights(pm25):
    # These are based on the Ikea VINDRIKTNING Manual
    if pm25 <= 3.5:
        tl = "Green"
    elif pm25 <= 8.5:
        tl = "Amber"
    else:    
        tl = "Red"
    return tl

def wifi_connect():
    global ssid
    global password
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(ssid, password)
    max_wait = 6
    while max_wait > 0:
        if wlan.status() < 0 or wlan.status() >= 3:
            break
        max_wait -= 1
        print("INFO: WIFI Waiting for connection...")
        time.sleep(2)
    if wlan.status() != 3:
        raise RuntimeError("INFO: WIFI Connection failed")
    else:
        status = wlan.ifconfig()
        print(f"INFO: WIFI connected - IP={status[0]}")
    addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1]
    wifi_socket = socket.socket()
    wifi_socket.bind(addr)
    wifi_socket.listen(1)
    print(f"INFO: WIFI Listening on port {str(addr[1])}")
    return wifi_socket

def serve_file(client, filename):
    with open(filename, 'rb') as f:
        while True:
            c = f.read(1024)
            if len(c) == 0:
                break
            client.sendall(c)

def wifi_thread():
    global vindriktning_readings
    global wifi_socket
    print("INFO: Starting Wifi Thread")
    while True:
        try:
            cl, addr = wifi_socket.accept()
            request = cl.recv(1024)
            print(f"INFO: Client connected from {str(addr)}")
            request = str(request).split()
            # reading = request.find('/reading')
            path = ""
            if len(request) > 2:
                path = request[1]
            if path == "/reading":
                stateis = str(vindriktning_readings)
                response = stateis
                cl.send('HTTP/1.0 200 OK\r\nContent-type: application/json\r\n\r\n')
            elif path == "/favicon.ico":
                cl.send('HTTP/1.0 200 OK\r\nContent-type: image/icon\r\n\r\n')
                serve_file(cl,"favicon.ico")
            else:
                cl.send('HTTP/1.0 200 OK\r\nContent-type: text/html\r\n\r\n')
                response = "use /reading to obtain information"
            cl.send(response)
            cl.close()
        except OSError as e:
            cl.close()
            print('INFO: Connection closed')

def uart_thread():
    # Thread - Serial Reading and processing
    global vindriktning_readings
    print("INFO: Listening to PM1006 Sensor")
    while True:
        data = uart0.read()
        if vindriktning_validpacket(data):
            vindriktning_readings = vindriktning_decode(data)
            print(vindriktning_readings)


# Thread 1 = Wifi Connectivity
wifi_socket = wifi_connect()

# thread = _thread.start_new_thread(wifi_thread,(ssid, password))
# wifi_thread(ssid, password)

thread = _thread.start_new_thread(uart_thread,())
wifi_thread()