esp-idf/examples/peripherals/adc/esp32c3/adc

Supported Targets	ESP32-C3

ADC DMA Example

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

This example shows how to use DMA-Read-APIs and Single-Read-APIs to read voltage from GPIO pins via ADC controller.

How to use example

Hardware Required

• A development board with ESP32C3 SoC
• A USB cable for power supply and programming

For single_read (Single-Read-APIs example), we use ADC1_CHANNEL_2, ADC1_CHANNEL_3, ADC1_CHANNEL_4, ADC2_CHANNEL_0. Hence we need to connect voltage sources (0 ~ 3.3V) to GPIO2, GPIO3, GPIO4, GPIO5 respectively.

For continuous_read (DMA-Read-APIs example), we use ADC1_CHANNEL_0, ADC1_CHANNEL_1 and ADC2_CHANNEL_0. Therefore, GPIO0, GPIO1 and GPIO5 should be connected to voltage sources (0 ~ 3.3V).

If other ADC units/channels are selected in your application, you need to change the GPIO pin (please refer to the ESP32C3 Technical Reference Manual).

Configure the project

idf.py menuconfig

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

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

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

Example Output

Running this example, you will see the following log output on the serial monitor:

I (322) ADC1_CH2: 7c8
I (322) ADC1_CH3: 278
I (322) ADC1_CH4: d4b
I (322) ADC2_CH0: 48

ADC1_CH0: 61b
ADC1_CH1: 39b
ADC2_CH0: 4b

Troubleshooting

• program upload failure

  • Hardware connection is not correct: run idf.py -p PORT monitor, and reboot your board to see if there are any output logs.
  • The baud rate for downloading is too high: lower your baud rate in the menuconfig menu, and try again.

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