DAC Output on Seed

dam28 · September 6, 2020, 1:44pm

Hi all!

I’m playing around with getting some CV outs and want to use the DACs onboard the seed. If I load up the LFO example for patch it works fine but if I follow the same idea on the seed I don’t get an output. Am I missing something fundamental?

Currently writing Oscillator values in the audio callback to the DAC as follows

dsy_dac_write(DSY_DAC_CHN1, freq1 * 4095);
dsy_dac_write(DSY_DAC_CHN2, freq1 * 4095);

antisvin · September 6, 2020, 2:01pm

It looks like you’ll need to initialize DAC outputs (once, when you patch starts) on Seed before using. Here’s how it’s done for patch:

github.com

electro-smith/libDaisy/blob/cbf9fb2e465bb1b3f35782a281be455db33114e5/src/daisy_patch.cpp#L201


}

void DaisyPatch::InitMidi()
{
    midi.Init(MidiHandler::MidiInputMode::INPUT_MODE_UART1,
              MidiHandler::MidiOutputMode::OUTPUT_MODE_UART1);
}

void DaisyPatch::InitCvOutputs()
{
    dsy_dac_init(&seed.dac_handle, DSY_DAC_CHN_BOTH);
    dsy_dac_write(DSY_DAC_CHN1, 0);
    dsy_dac_write(DSY_DAC_CHN2, 0);
}

void DaisyPatch::InitEncoder()
{
    encoder.Init(seed.GetPin(PIN_ENC_A),
                 seed.GetPin(PIN_ENC_B),
                 seed.GetPin(PIN_ENC_CLICK),
                 AudioCallbackRate());

The reason why it’s not done on Seed is probably that its pins can be reconfigured for different purposes. In case of DAC outputs, they can also be configured as ADC inputs. So you’ll have to explicitly configure it due to Daisy’s limited telepathic abilities.

dam28 · September 6, 2020, 3:26pm

thank you so much, I spent a while reading through that document as well!

Thank you again.

D