008 – ESP32 MicroPython: Hardware Timer Interrupts
In this tutorial, we will learn how to use the hardware Timer Interrupts of ESP32 in MicroPython. Timer in essence is basically a counter that either counts up or counts down. Timers can be use to trigger an interrupt event when an overflow happened or a certain count value is reached.
Circuit Diagram:
Video Description:
If you have any question or suggestion, please do not hesitate to write it in the comment box provided.
If you find this article as helpful, please kindly consider supporting my Youtube channel by Subscribing. Please click this to Subscribe to TechToTinker.
Source Code:
Example # 1 Simple Timer:
import machine
led = machine.Pin(2, machine.Pin.OUT)
tim0 = machine.Timer(0)
def handle_callback(timer):
led.value( not led.value() )
# tim0.init(period=2000, mode=machine.Timer.ONE_SHOT, callback=lambda t: led.value(not led.value()))
tim0.init(period=50, mode=machine.Timer.PERIODIC, callback=handle_callback)
Example # 2 Hardware Timer Interrupts use for multithreading:
# Load the machine module
import machine
# 1. Create the GPIO object as
# normal GPIO pin assignment
p23 = machine.Pin(23, machine.Pin.OUT)
p22 = machine.Pin(22, machine.Pin.OUT)
# 2. Create the servo object and
# attach the pwm driver to the GPIO pin
b_servo = machine.PWM(p23)
s_servo = machine.PWM(p22)
# Initialize the servo object with
# 20ms pulse interval and set the
# angle to 0 degree
b_servo.init(freq=50, duty=20)
s_servo.init(freq=50, duty=20)
# 3. Create a timer object for both servo
timB = machine.Timer(0)
timS = machine.Timer(1)
# Functions to handle the Timer callbacks
def handle_timB(timer):
global is_timB
is_timB = True
def handle_timS(timer):
global is_timS
is_timS = True
# and initialize the timer objects
timB.init(period=200, mode=machine.Timer.PERIODIC, callback=handle_timB)
timS.init(period=100, mode=machine.Timer.PERIODIC, callback=handle_timS)
# Create a global variables
is_timB = False
is_timS = False
b_angle = 0
s_angle = 0
# Functions:
# Converts a value using map function of Arduino
# this basically functions like by ratio and proportion
def map(x, in_min, in_max, out_min, out_max):
return int((x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min)
# Function to convert an angle to a duty value
def servo(pin, angle):
pin.duty(map(angle, 0, 180, 20, 120))
# Main loop
while True:
# Checks if the Timer interrupt sets the global variable
if is_timB==True:
is_timB = False # disable the flag
servo(b_servo, b_angle) # rotate the servo
if b_angle < 180: # if the angle is less than 180
b_angle += 10 # increment the angle
if is_timS==True:
is_timS = False
servo(s_servo, s_angle)
if s_angle < 180:
s_angle += 5
