I have checked both DAC1 and DAC2 outputs on a scope and find that all I get out of both DAC pins is a about a 100 millivolt ripple on top of about a 250 millivolt DC voltage, when sending samples corresponding to an audio tone signal to the DAC. If I send a fixed value, any value between 0 to 255 I ...

I am using the Firebeetle ESP32 board by DFROBOT DFR0478
There is a schematic on their web site and pinouts diag. and it doesnt show anything connected to the DAC pins.
And I don't see anything connected on the board. I have nothing else connected except the USB port.

It uses the DFROBOT ESP-WROOM ...

Have also discovered that I can only send a waveform sample of amplitude up to max of about 100.
That is... sin(i/256*2*PI)*50+52. for 256 samples in array.
Any larger than this and it gets distorted starts to look like full wave rectifier again...????

But the smaller ..... *30 + 30 say ..... are ...

This thread was initially about ESP32 IDF on Linux and problems with I2S, but when I could not get the I2S example working I then tried on a windows pc with Arduino IDE and the ESP IDF tools etc. So all of the problem solving till now has be on windows with Arduino etc.

Now that I got 1 channel ...

I tried dacWrite and it behaves the same way.... one channel is about 1/4 the amplitude of the other for the same signal.


also DAC may be enabled on these pins all the time.... dac_output_enable or dac_output_disable did not seem to do anything....?????

Yes, thanks, It works now...I was either mixed up or confused...???.....I think I simply didn't know...??

Got it also working with 128 sample array and change i2s writebytes to 512 also had to change i2s_config.dma_buf_len to 64...but it worked..... How do you determine the dma_buf_len and number ...

I have tried various options with the setting and config and cannot get it to work properly.
If I set ...... samples = (sample8 ) + (sample24 ); I get the sine wave with what looks like the bottom part inverted as in full wave rectification.....but it outpust sound.

If I set ..... samples[i/2 ...

This version of modifications give me a sinwave from both DAC at the same time.
But I still do not understand exactly why......

Uint32_t sample(256] ......array size 256..????? datatype changed to Uint32_t.....prob allows left and right together in each sample..??
.dma_buf_count = 2,
.dma_buf_len ...

I have got it working......but only on one DAC channel. Using the example posted here..
I have tried various combinations of the settings and still only output on one DAC channel.
I think my orig problem was getting the config settings correct and not sending data correctly.
Basically I dont ...

Thanks for reply. I tried that and i2s_set_dac_mode(I2S_DAC_CHANNEL_BOTH_EN);
If I use dacWrite and send values direct to the DAC port I get sound or noise out.
Is there a way to send simple data direct to the I2S which I can read or see blips or sounds at the DAC...The I2S is supposed to be mapped ...