Useful Tips and Tricks for the Raspberry Pi Pico

Question

The Raspberry Pi Pico is a versatile and affordable microcontroller that opens up a world of possibilities for hobbyists and developers. Here are a few practical tips and tricks to help you get the most out of your Raspberry Pi Pico.

1. Dual-Core Programming with MicroPython

The Raspberry Pi Pico's RP2040 chip has two cores, which you can utilize for parallel tasks. In MicroPython, you can run separate functions on each core using the _thread module. For example, one core can handle sensor readings while the other manages a display.

import _thread
import time

def core1_task():
    while True:
        print("Running on Core 1")
        time.sleep(1)

def core0_task():
    while True:
        print("Running on Core 0")
        time.sleep(1)

_thread.start_new_thread(core1_task, ())
core0_task()

Tip: Ensure shared resources (like GPIO pins) are managed carefully to avoid conflicts between cores.

2. Power-Saving with Sleep Modes

To save power in battery-powered projects, use the Pico’s sleep modes. You can put the Pico into a low-power state using MicroPython’s machine.lightsleep() or machine.deepsleep(). For example:

import machine
import time

# Enter light sleep for 5 seconds
machine.lightsleep(5000)

Tip: Use deep sleep for ultra-low power consumption, but note that it resets the program unless you save state to RTC memory.

3. Using PIO for Custom Protocols

The Pico’s Programmable Input/Output (PIO) system is a powerful feature for creating custom communication protocols or handling precise timing. For instance, you can use PIO to drive WS2812B (NeoPixel) LEDs without taxing the CPU.

from machine import Pin
from rp2 import PIO, StateMachine
from rp2.asm_pio import asm_pio

@asm_pio(sideset_init=PIO.OUT_LOW)
def ws2812():
    T1 = 2
    T2 = 5
    T3 = 3
    wrap_target()
    label("bitloop")
    out(x, 1)               .side(0)    [T3 - 1]
    jmp(not_x, "do_zero")   .side(1)    [T1 - 1]
    jmp("bitloop")          .side(1)    [T2 - 1]
    label("do_zero")
    nop()                   .side(0)    [T2 - 1]
    wrap()

# Example: Send RGB data to a NeoPixel
sm = StateMachine(0, ws2812, freq=8000000, sideset_base=Pin(0))
sm.active(1)

Tip: Study the RP2040 datasheet for PIO instructions to create custom protocols like I2S or custom serial interfaces.