EZ Timer

We often need to run things at regular interval (eg. print a message or blink an LED every second). Using a sleep command is an easy solution, but during the sleep, the microcontroller cannot do anything else.

This can be a problem with certain hardware (eg. GPS needs to run update frequently to read data, gyro needs the same to calculate headings). It can also be an issue if you need to read sensors or inputs (ie. you can't check if a button is pressed until the sleep ends).

The EZ Timer extension allows you to run things at regular intervals or after a delay, but without using sleep.

Code

We have a few examples here.

• Basic Demonstrates the basic use of EZ Timer.

• Simultaneous Demonstrates doing two things simultaneously (detect button press and print to monitor).

• Offset Demonstrates using offset to blink an LED.

• Gyro / GPS Demonstrates using EZ Timer to update the Gyro and GPS frequently, while printing the result out infrequently. You'll need to connect a Gyro and GPS to run this example.

Blocks

Basic

Simultaneous

Offset

The second timer block runs at the same frequency as the first (0.2s), but the offset of 0.1s makes it start slightly later.

Gyro / GPS

Python

Basic

import ez_timer
import time

def print_time():
    print(time.ticks_ms())

ez_timer_obj = ez_timer.Timer()
ez_timer_obj.set_interval(print_time, 1)

while True:
    ez_timer_obj.update()

Simultaneous

import ez_timer
import time
from ioty import pin

def print_time():
    print(time.ticks_ms())

ez_timer_obj = ez_timer.Timer()
ez_timer_obj.set_interval(print_time, 1)

while True:
    if pin.digital_read(0) == 0:
        pin.digital_write(2, 1)
    else:
        pin.digital_write(2, 0)
    ez_timer_obj.update()

Offset

import ez_timer
from ioty import pin

def led_on():
    pin.digital_write(2, 1)

def led_off():
    pin.digital_write(2, 0)

ez_timer_obj = ez_timer.Timer()
ez_timer_obj.set_interval(led_on, 0.2)
ez_timer_obj.set_interval(led_off, 0.2, offset=0.1)

while True:
    ez_timer_obj.update()

Gyro / GPS

import machine
import mpu6050
import gps
import ez_timer

def print_readings():
    print(mpu6050_device.angle_z())
    print(gps_device.get_lat())
    print(gps_device.get_lng())

i2c0 = machine.I2C(0, freq=100000)
mpu6050_device = mpu6050.MPU6050(i2c0, 104)
mpu6050_device.calibrate_gyro()

uart1 = machine.UART(1, baudrate=9600, tx=4, rx=5)
gps_device = gps.GPS(uart1)

ez_timer_obj = ez_timer.Timer()
ez_timer_obj.set_interval(print_readings, 1)

while True:
    mpu6050_device.update_angle()
    gps_device.update()
    ez_timer_obj.update()

Results

Basic

You should see the time (...in ms) printed in the monitor every second.

Simultaneous

Same as in Basic, you should see the time (...in ms) printed in the monitor every second. If you press the boot button, the built-in Blue LED should light up immediately.

Offset

You should see the built-in Blue LED blink rapidly (...5 times per second).

Gyro / GPS

You should see the gyro heading and GPS position printed in the monitor every second.

Timer - easy to use, non-blocking timer