Wireless multimeter over UDP

main.py

# Using an ESP32 (Super Mini C3)
#
# How it works:
#   The latest ADC voltage value is sent over UDP
#
# Usage:
#   Connect over netcat port 33
#
#   $> nc <ip> 33
from network import WLAN
from machine import Pin, ADC, idle
from time import sleep_ms

import socket

SSID = "<ssid>"
PASSWORD = "<wifi password>"
ADC_PIN = 1

pin = Pin(ADC_PIN, Pin.IN)
adc = ADC(pin, atten=ADC.ATTN_11DB)

def start_wlan():
  wlan = WLAN(WLAN.IF_STA)
  wlan.active(True)
  wlan.connect(SSID, PASSWORD)

  while not wlan.isconnected():
    idle()
    sleep_ms(100)

  ip = wlan.ipconfig('addr4')
  print(f'wlan connected {ip}')

def start_udp_server():
  sock = socket.socket(socket.SOCK_DGRAM)
  sock.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
  sock.bind(('0.0.0.0', 33))
  sock.listen()

  print(f'listening on 0.0.0.0:33')

  while True:
    client, addr = sock.accept()
    print(f'client connected {addr}')

    while True:
      voltage = adc.read_uv() / 1_000_000.0

      try:
        buf = client.send(f"{voltage}v\n")
      except: # FAFO
        break
      finally:
        sleep_ms(500)

    print(f'client closed {addr}')
    client.close()

start_wlan()
start_udp_server()