Python for Hardware

Using hardware interfaces with Python requires specific binary libraries. Thus, it is not as easily exchangeable among platforms as the hardware-aware part of the code. Below are some hardware-related samples for Python and Micropython.

The following code presents a sample Python application that flashes an LED connected to Raspberry Pi's GPIO pin 16. One must build a circuit (LED + resistor of a proper value) and connect it to the GPIO before running the code.
This example uses a dedicated GPIO handling library (specific for hardware): RPi.GPIO. For other IoT platforms, this may vary. For example, Micropython uses a Machine library instead—it covers all the microcontroller's hardware.

import RPi.GPIO as GPIO  
import time
 
def blink(pin):  
    GPIO.output(pin,GPIO.HIGH)  
    time.sleep(1)  
    GPIO.output(pin,GPIO.LOW)  
    time.sleep(1)  
    return  
 
GPIO.setmode(GPIO.BCM)  
GPIO.setup(16, GPIO.OUT)  
 
for i in range(0,5):  
    blink(16)  
GPIO.cleanup()

A code equivalent for the above algorithm to run in Micropython (here for RP2040) looks quite similar:

import machine
import time
 
led=machine.Pin(16, machine.Pin.OUT)
 
def blink():
    led.toggle()
    time.sleep(1)
    led.toggle()
    time.sleep(1)
 
led.value(0)
 
for i in range(5):
    blink()

Similarly to the GPIO, interrupts are hardware-specific; thus, libraries may differ among platforms, hence Python syntax. The sample present below is for Raspberry Pi (regular Python), and the following code is for RPi Pico (RP2040, Micropython).

import RPi.GPIO as GPIO
import time
 
led_last = time.time_ns()
led_state = GPIO.LOW
 
GPIO.setmode(GPIO.BCM)
GPIO.setup(16, GPIO.OUT, initial=led_state)
GPIO.setup(17, GPIO.IN, pull_up_down=GPIO.PUD_UP)
 
def btnHandler(pin):
    global led_test, led_state
    if (led_state==GPIO.LOW):
        led_state=GPIO.HIGH
    else:
        led_state=GPIO.LOW
    GPIO.output(16, led_state)
 
GPIO.add_event_detect(17, GPIO.FALLING, callback=btnHandler, bouncetime=200)
 
while(True):
    time.sleep(0)

The sample code for RP2040 Micropython is present below, and its implementation live, via serial port, directly on the MCU is present in the figure 1:

import machine
import time
import utime
led=machine.Pin(16, machine.Pin.OUT)
btn=machine.Pin(15, machine.Pin.IN, machine.Pin.PULL_UP)
led_last = time.ticks_ms()
 
def btnHandler(pin):
    global led, led_last, btn
    if (time.ticks_diff(time.ticks_ms(), led_last)) > 500:
        led.toggle()
        led_last=time.ticks_ms()
 
led.value(0)
btn.irq(trigger=machine.Pin.IRQ_RISING, handler=btnHandler)