(See the README.md file in the upper level 'examples' directory for more information about examples.)
## Overview
This example shows the basic usage of outputting cosine wave by the DAC driver. The cosine wave is generated by the hardware cosine wave generator in the DAC module.
This example will output cosine wave on both channels.
- Note that some ESP32-S2 DevKits have LED on it which is connected to GPIO18 (same pin as DAC channel1), so the output voltage of DAC channel 1 can't go down due the this LED.
Note that as we use the ADC to monitor the output data, we need to set false to `CONFIG_ADC_DISABLE_DAC_OUTPUT` in the menuconfig, otherwise the ADC will shutdown the DAC power to guarantee it won't be affect by DAC.
Build the project and flash it to the board, then run monitor tool to view serial output:
```
idf.py -p PORT flash monitor
```
(Replace PORT with the name of the serial port to use.)
(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
The DAC channels can be read by ADC channels internally. The ADC read period is 100 ms, the following log is the raw ADC value read from the DAC channels. But since the ADC sample-rate might be lower than the DAC cosine period, the sampling value can only indicate that the voltage is changing.
If monitoring the DAC channels with an oscilloscope, there will be two cosine waves with opposite phase and different amplitude at 8000 Hz on the two DAC channels.
