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

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2022-06-22 04:28:32 -04:00
| Supported Targets | ESP32 | ESP32-C3 | ESP32-S2 | ESP32-S3 |
| ----------------- | ----- | -------- | -------- | -------- |
# Sigma Delta Modulation Example
(See the README.md file in the upper level 'examples' directory for more information about examples.)
This example uses the sigma-delta driver to generate modulated output on a GPIO. If you connect a LED or LCD backlight control to the output GPIO, you will see it slowly brightening and dimming.
## How to use example
### Hardware Required
* A development board with any supported Espressif SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
* A USB cable for Power supply and programming
* An LED and a resistor to limit the LED current. Connect them as below:
```
330R LED
EXAMPLE_SIGMA_DELTA_GPIO_NUM +----/\/\/\----+------|>|-----+ GND
```
### Configure the project
You can change the GPIO number by [EXAMPLE_SIGMA_DELTA_GPIO_NUM](main/sdm_example_main.c).
### Build and Flash
Build the project and flash it to the board, then run the monitor tool to view the serial output:
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
Once the upload is complete and the board is reset, the program should start running. This is reported on the monitor as below:
```
...
I (245) cpu_start: Starting scheduler.
I (249) example: Install sigma delta channel
I (249) gpio: GPIO[0]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
I (259) example: Enable sigma delta channel
I (259) example: Change duty cycle continuously
```
Immediately after that the LED should start brightening and dimming.
## 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.