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68 lines
2.3 KiB
Markdown
68 lines
2.3 KiB
Markdown
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# ADC DMA 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 shows how to use ADC Continuous Read Mode (DMA Mode) to read from GPIO pins via on-chip ADC module(s).
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## How to use example
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### Hardware Required
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* A development board with ESP32, ESP32-S and ESP32-C SoC
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* A USB cable for power supply and programming
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Please refer to the `channel` array defined in `adc_dma_example_main.c`. These GPIOs should be connected to voltage sources (0 ~ 3.3V). If other ADC unit(s) / channel(s) are selected in your application,
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feel free to modify these definitions.
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### Configure the project
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```
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idf.py menuconfig
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```
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### Build and Flash
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Build the project and flash it to the board, then run monitor tool to view serial output:
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```
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idf.py -p PORT flash monitor
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```
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(To exit the serial monitor, type ``Ctrl-]``.)
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See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
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## Example Output
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Running this example, you will see the following log output on the serial monitor:
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```
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I (338) ADC DMA: adc_pattern[0].atten is :0
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I (348) ADC DMA: adc_pattern[0].channel is :2
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I (348) ADC DMA: adc_pattern[0].unit is :0
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I (358) ADC DMA: adc_pattern[1].atten is :0
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I (358) ADC DMA: adc_pattern[1].channel is :3
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I (368) ADC DMA: adc_pattern[1].unit is :0
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I (368) ADC DMA: adc_pattern[2].atten is :0
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I (378) ADC DMA: adc_pattern[2].channel is :0
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I (378) ADC DMA: adc_pattern[2].unit is :1
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I (388) TASK:: ret is 0, ret_num is 256
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I (388) ADC DMA: Unit: 1,_Channel: 2, Value: bec
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I (398) ADC DMA: Unit: 2,_Channel: 0, Value: 9cb
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I (398) ADC DMA: Unit: 1,_Channel: 3, Value: acb
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I (408) ADC DMA: Unit: 2,_Channel: 0, Value: 966
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I (408) ADC DMA: Unit: 1,_Channel: 2, Value: b63
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I (418) ADC DMA: Unit: 2,_Channel: 0, Value: 8ff
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I (418) ADC DMA: Unit: 1,_Channel: 3, Value: a6b
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I (428) ADC DMA: Unit: 2,_Channel: 0, Value: 8a2
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...
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```
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## Troubleshooting
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* program upload failure
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* Hardware connection is not correct: run `idf.py -p PORT monitor`, and reboot your board to see if there are any output logs.
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* The baud rate for downloading is too high: lower your baud rate in the `menuconfig` menu, and try again.
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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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