Timer Usage Tutorial#

What is Timer?#

Timer is a hardware module used to execute tasks at fixed time intervals. Common uses include:

Periodically executing callback functions (such as timed printing, timed collection)
One-time delayed trigger events (such as startup delay)
Implementing software timers, clocks, task scheduling, and other functions

K230 Timer Features#

Feature	Description
Number of timers	Built-in 6 hardware timers
Time precision	Minimum period is 1 microsecond
Supported modes	One-shot mode (`ONE_SHOT`), periodic mode (`PERIODIC`)
Supported types	Hardware timer / Software timer (number -1)
Callback mechanism	Automatically calls the user-specified function on timeout

Application Example: Timed Print Task#

The following example demonstrates how to use Timer to achieve:

One-time delayed execution
Periodic timed triggering
Resource release

Example Code#

from machine import Timer
import time

# ========= Create timer ========= #
tim = Timer(-1)  # -1 indicates software timer

# ========= One-shot mode: trigger after 100ms ========= #
tim.init(period=100, mode=Timer.ONE_SHOT, callback=lambda t: print("单次触发：1"))
time.sleep(0.2)  # Main program delays 200ms to ensure callback triggers

# ========= Periodic mode: trigger once per second ========= #
tim.init(freq=1, mode=Timer.PERIODIC, callback=lambda t: print("周期触发：2"))
time.sleep(2)  # Main program waits 2 seconds to observe output

# ========= Release timer ========= #
tim.deinit()

Key Parameter Description#

Parameter	Type	Description
`period`	Integer (ms)	Timer period (in milliseconds), used for one-shot or periodic timing. The minimum `period` for K230 is 5ms.
`freq`	Integer (Hz)	Timer frequency (in Hertz), `1Hz` means triggering once per second
`mode`	Constant	`Timer.ONE_SHOT` (one-shot) or `Timer.PERIODIC` (periodic)
`callback`	Function	Function automatically called when the timer triggers

Mode Details#

One-Shot Mode `Timer.ONE_SHOT`#

tim.init(period=100, mode=Timer.ONE_SHOT, callback=func)

Timer triggers only once
Automatically stops when the time is up

Periodic Mode `Timer.PERIODIC`#

tim.init(freq=2, mode=Timer.PERIODIC, callback=func)

Triggers once every 0.5 seconds
Will continue running until manually stopped

Usage Notes#

Note	Description
Software Timer Number	Software timers created with `Timer(-1)` do not occupy hardware resources
Callback Execution Timing	The callback function runs in the system interrupt context; avoid blocking operations or `sleep()`
No Re-initialization	If a Timer is running, calling `init()` again will overwrite the previous setting
Resource Release	Use `tim.deinit()` to stop and release timer resources

Application Scenarios#

Real-time timing control: LED blinking, buzzer alarms
Periodic sampling: sensor data reading
Timeout control: task execution timeout handling
System heartbeat: periodically printing an “alive” flag

Tip

For detailed usage of the Timer module, please refer to the K230 Timer API Documentation