uart-commandes.py
A mini command server on UART0 (GP0/GP1): classic serial modules (GPS, cellular modem, another microcontroller) can toggle the LED, read the temperature or poll the board with simple text lines.
Hardware
A generic RP2350 (dual Cortex-M33) board programmed with MicroPython. A 3.3 V serial module or a USB-serial cable to test (never exceed 3.3 V on RX/TX).
Wiring
TX (GP0) to module RX, RX (GP1) to module TX, common grounds. Power the module at 3.3 V or add a level shifter.
How it works
uart.any() reports received bytes without blocking; the buffer is split on lines. Each command returns one reply line, a format that is easy to extend.
Running it
Flash the « RP2350 » MicroPython build via BOOTSEL (.uf2), then copy the script to the drive. The user LED pin varies by manufacturer: check the board documentation.
Variants
Raise the baud rate (921600) for data streams, or move to UART1 (GP4/GP5) to keep the MicroPython shell on USB.
uart-commandes.py
# Serveur de commandes sur UART0 (GP0 = TX, GP1 = RX) a 115200 bauds.
# Permet de dialoguer avec un module serie (GPS, modem, autre carte).
from machine import UART, Pin
import machine
import time
uart = UART(0, baudrate=115200, tx=Pin(0), rx=Pin(1))
led = Pin(25, Pin.OUT)
buffers = b""
print("UART0 pret : 'l' bascule, 't' temperature, 's' etat")
def temperature():
adc = machine.ADC(4)
v = adc.read_u16() * 3.3 / 65535.0
return 27.0 - (v - 0.706) / 0.001721
while True:
if uart.any(): # octets disponibles ?
buffers += uart.read(uart.any())
while b"
" in buffers: # decoupage en lignes
ligne, buffers = buffers.split(b"
", 1)
cmd = ligne.strip().decode("utf-8", "ignore").lower()
if cmd == "l":
led.value(not led.value())
uart.write("LED=%d
" % led.value())
elif cmd == "t":
uart.write("T=%.1f
" % temperature())
elif cmd == "s":
uart.write("OK uptime=%d
" % (time.ticks_ms() // 1000))
time.sleep_ms(10)