esp-idf/examples/peripherals/timer_group/README.md

Example: General Purpose Timer

This example uses the timer group driver to generate timer interrupts at two specified alarm intervals.

How to Use Example

Hardware Required

• A development board with ESP SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for Power supply and programming

Build and Flash

Run idf.py -p PORT flash monitor to build, flash and monitor the project.

(To exit the serial monitor, type Ctrl-].)

See the ESP-IDF Getting Started Guide for all the steps to configure and use the ESP-IDF to build projects.

Example Output

Timer Group with auto reload
Group[0], timer[0] alarm event
------- EVENT TIME --------
Counter: 0x0000000000000008
Time   : 0.00000160 s
-------- TASK TIME --------
Counter: 0x0000000000004ed8
Time   : 0.00403680 s
Timer Group without auto reload
Group[1], timer[0] alarm event
------- EVENT TIME --------
Counter: 0x00000000017d7848
Time   : 5.00000160 s
-------- TASK TIME --------
Counter: 0x00000000017dcb32
Time   : 5.00424680 s
Timer Group with auto reload
Group[0], timer[0] alarm event
------- EVENT TIME --------
Counter: 0x0000000000000008
Time   : 0.00000160 s
-------- TASK TIME --------
Counter: 0x0000000000004dd4
Time   : 0.00398480 s

Functionality Overview

• Two timers are configured
• Each timer is set with some sample alarm interval
• On reaching the interval value each timer will generate an alarm
• One of the timers is configured to automatically reload it's counter value on the alarm
• The other timer is configured to keep incrementing and is reloaded by the application each time the alarm happens
• Alarms trigger subsequent interrupts, that is tracked with messages printed on the terminal:

Troubleshooting

For any technical queries, please open an issue on GitHub. We will get back to you soon.