esp-idf/examples/peripherals/mcpwm/mcpwm_servo_control/README.md

| Supported Targets | ESP32 | ESP32-S3 |
| ----------------- | ----- | -------- |
# MCPWM RC Servo Control Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example illustrates how to drive a typical [RC Servo](https://en.wikipedia.org/wiki/Servo_%28radio_control%29) by sending a PWM signal using the MCPWM driver. The PWM pulse has a frequency of 50Hz (period of 20ms), and the active-high time (which controls the rotation) ranges from 0.5s to 2.5ms with 1.5ms always being center of range.

## How to Use Example

### Hardware Required

* A development board with any Espressif SoC which features MCPWM peripheral (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
* A USB cable for Power supply and programming
* A RC servo motor, e.g. [SG90](http://www.ee.ic.ac.uk/pcheung/teaching/DE1_EE/stores/sg90_datasheet.pdf)

Connection :

```
      ESP Board              Servo Motor      5V
+-------------------+     +---------------+    ^
|  SERVO_PULSE_GPIO +-----+PWM        VCC +----+
|                   |     |               |
|               GND +-----+GND            |
+-------------------+     +---------------+
```

Note that, some kind of servo might need a higher current supply than the development board usually can provide. It's recommended to power the servo separately.

### 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 [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html) for full steps to configure and use ESP-IDF to build projects.


## Example Output

Run the example, you will see the following output log:

```
...
I (0) cpu_start: Starting scheduler on APP CPU.
I (305) example: Create timer and operator
I (305) example: Connect timer and operator
I (305) example: Create comparator and generator from the operator
I (315) gpio: GPIO[44]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
I (325) example: Set generator action on timer and compare event
I (335) example: Enable and start timer
I (335) example: Angle of rotation: 0
I (1345) example: Angle of rotation: 2
I (2345) example: Angle of rotation: 4
I (3345) example: Angle of rotation: 6
I (4345) example: Angle of rotation: 8
I (5345) example: Angle of rotation: 10
I (6345) example: Angle of rotation: 12
I (7345) example: Angle of rotation: 14
I (8345) example: Angle of rotation: 16
I (9345) example: Angle of rotation: 18
...
```

The servo will rotate from -90 degree to 90 degree, and then turn back again.

## Troubleshooting

For any technical queries, please open an [issue] (https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.