Pi Pico W Expansion Board: Basic Emon CMS Client API Call

[VincentSaelzler]

Is this line just a sample/placeholder, or is it actually supposed to send valid requests to Emon CMS?

req = "https://emoncms.org/input/post?apikey=apikey&node=emontx4pico&data="+data

Link to File

I am asking because it seems to send back a 200 response with the content being ok regardless of whether I send the correct or incorrect API key.

I am working on a more robust micropython client, and have gotten to the point of actually making the API call to Emon CMS.

from machine import UART, Pin
from time import sleep

# UART configuration ---------------------------------------------------------
# default timeout for uart.any() to decide if a new line is coming is 0 (ms).
# increase to 1 (ms) to give emon time to send the next line.
# sending output to uart1 is optional - for debugging
# required to debug because if the micro-usb cable is plugged to pico
# the power cannot simultaneously be connected to emon (3.3V vs 5V)

uart0 = UART(0, timeout=1) # pins GP0/GP1
uart1 = UART(1)  # pins GP4/GP5


def blink_led(times_to_blink):
    # assumptions
    led = Pin('LED', Pin.OUT)
    a_brief_moment = .1
    # start with the led off
    led.value(0)
    for _ in range(times_to_blink):
        # turn on and wait
        led.toggle()
        sleep(a_brief_moment)
        # turn back off and wait
        led.toggle()
        sleep(a_brief_moment)


def process_line():
    line = read_line()
    trimmed_line = line.strip()

    # for now just write output to console and outgoing uart
    uart1.write(line)
    print(trimmed_line)

    # trimmed line looks something like:
    # MSG:540,Vrms:240.00,P1:2,P2:6,P3:6,P4:5,P5:5,P6:4,E1:3,E2:10,E3:10,E4:8,E5:8,E6:7,pulse:0
    # TODO: Make a correct API call
    
def read_line():
    try:
        # get input until a newline character is reached (or the uart's configured timeout_char expires)
        incoming_line = uart0.readline()

        if incoming_line is None:
            # blink thrice to signal an error
            blink_led(3)
            return('Readline Error: No Input')
        
        # return the line in string format
        return incoming_line.decode('utf-8')
    
    except UnicodeError:
        # blink thrice to signal an error
        blink_led(3)
        return('Unicode Error: '+ str(incoming_line))


def main():
    while True:
        
        # if one or more lines of incoming data are available
        if uart0.any():
            # while there is still data available
            while uart0.any():
                # process the next line of data
                process_line()
            
            # blink once to signal that line(s) came in
            blink_led(1)
        else:
            # blink twice to signal that nothing came in
            blink_led(2)

        # wait a few seconds
        sleep(2)