How To: Digital/Analog Converter

Core Module contains two analog outputs: DAC0 and DAC1. These are real analog outputs, not just PWM outputs.

Both channels can run completely separately with different sample rates.

References

DAC SDK Module
GitHub Repository Example

info

In this example, there’s a sine wave lookup table, you need to prepare the output buffer first.

The sampling is set on TWR_DAC_SAMPLE_RATE_16K. This together generates 125 Hz sine-wave on DAC0 output.

Sine Wave Generator Code Example

#include <application.h>

const uint8_t sine_wave[] = {
0x80, 0x86, 0x8C, 0x93,
0x99, 0x9F, 0xA5, 0xAB,
0xB1, 0xB6, 0xBC, 0xC1,
0xC7, 0xCC, 0xD1, 0xD5,
0xDA, 0xDE, 0xE2, 0xE6,
0xEA, 0xED, 0xF0, 0xF3,
0xF5, 0xF8, 0xFA, 0xFB,
0xFD, 0xFE, 0xFE, 0xFF,
0xFF, 0xFF, 0xFE, 0xFE,
0xFD, 0xFB, 0xFA, 0xF8,
0xF5, 0xF3, 0xF0, 0xED,
0xEA, 0xE6, 0xE2, 0xDE,
0xDA, 0xD5, 0xD1, 0xCC,
0xC7, 0xC1, 0xBC, 0xB6,
0xB1, 0xAB, 0xA5, 0x9F,
0x99, 0x93, 0x8C, 0x86,
0x80, 0x7A, 0x74, 0x6D,
0x67, 0x61, 0x5B, 0x55,
0x4F, 0x4A, 0x44, 0x3F,
0x39, 0x34, 0x2F, 0x2B,
0x26, 0x22, 0x1E, 0x1A,
0x16, 0x13, 0x10, 0x0D,
0x0B, 0x08, 0x06, 0x05,
0x03, 0x02, 0x02, 0x01,
0x01, 0x01, 0x02, 0x02,
0x03, 0x05, 0x06, 0x08,
0x0B, 0x0D, 0x10, 0x13,
0x16, 0x1A, 0x1E, 0x22,
0x26, 0x2B, 0x2F, 0x34,
0x39, 0x3F, 0x44, 0x4A,
0x4F, 0x55, 0x5B, 0x61,
0x67, 0x6D, 0x74, 0x7A
};

void application_init(void)
{
    twr_dac_init(TWR_DAC_DAC0);

    twr_dac_config_t dac_config;

    dac_config.buffer = (uint8_t*)sine_wave;
    dac_config.length = sizeof(sine_wave);
    dac_config.data_size = TWR_DAC_DATA_SIZE_8;
    dac_config.mode = TWR_DAC_MODE_CIRCULAR;
    dac_config.sample_rate = TWR_DAC_SAMPLE_RATE_16K;

    twr_dac_async_config(TWR_DAC_DAC0, &dac_config);

    twr_dac_async_run(TWR_DAC_DAC0);
}

References​

References