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55 lines
2.0 KiB
Markdown
55 lines
2.0 KiB
Markdown
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| Supported Targets | ESP32 | ESP32-C3 | ESP32-S2 | ESP32-S3 |
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| ----------------- | ----- | -------- | -------- | -------- |
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# Sigma Delta Modulation Example
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(See the README.md file in the upper level 'examples' directory for more information about examples.)
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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.
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## How to use example
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### Hardware Required
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* A development board with any supported Espressif SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
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* A USB cable for Power supply and programming
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* An LED and a resistor to limit the LED current. Connect them as below:
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```
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330R LED
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EXAMPLE_SIGMA_DELTA_GPIO_NUM +----/\/\/\----+------|>|-----+ GND
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```
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### Configure the project
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You can change the GPIO number by [EXAMPLE_SIGMA_DELTA_GPIO_NUM](main/sdm_example_main.c).
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### Build and Flash
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Build the project and flash it to the board, then run the monitor tool to view the serial output:
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Run `idf.py -p PORT flash monitor` to build, flash and monitor the project.
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(To exit the serial monitor, type ``Ctrl-]``.)
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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.
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## Example Output
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Once the upload is complete and the board is reset, the program should start running. This is reported on the monitor as below:
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```
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...
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I (245) cpu_start: Starting scheduler.
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I (249) example: Install sigma delta channel
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I (249) gpio: GPIO[0]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
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I (259) example: Enable sigma delta channel
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I (259) example: Change duty cycle continuously
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```
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Immediately after that the LED should start brightening and dimming.
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## Troubleshooting
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For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.
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