WT588D-U use of DAC audio output?

Using Arduino Microcontrollers
#1

Hello I have a WTD588D-U
When I use the PMW output with a speaker like this, all is good:

I want to test DAC output so I did it like this but the sound seems to be too high for my amp (2 basics amplified speakers), I ear only lots off distortion, did I miss something?

thx

WTD.png

#2

Hi.

b6c46fc2f886aea34fa0a8dcb93e12195a2a6fea.png

Did you read the datasheet, telling you how to use the DAC output ?
The datasheet can be found in this link.

It tells you you need to use a 1K2 resistor and a 104 capacitor to use it.
That is the datasheet of the chip, not that of the module.
It is very well possible that some module already has these extra components on board.
I can’t tell off of your picture above, but i do know that the chip’s pin for DAC out, is the same as that for PWM+ out.
So it is always PWM+, and a resistor/capacitor combination will form the last and essential step of a close to real DAC.

So check for the presence of that resistor and capacitor, and if it is not, add them yourself.

It is supposed to be connected like this:

Chip output
     |
 Resistor 
     |
     +------> DAC output toward your amplifier
     |
 Capacitor
     | 
    GND
#3

Yes indeed you seem to be right.
I wonder why they do a separate PMW and DAC if it is the same thing

#4

So your schema almost work, I have to put the Dac before the Resistor

Chip output
     |
     +------> DAC output toward your amplifier
     |
 Resistor (1K)
     |
    GND ------> To amp

The capacitor after the resistor was messing the sound (100µf)

#5

100 µF ?
That's got to be way too large for this purpose.
So i googled to find a conversion table.
104 isn't 100 µF.
It is 0.1 µF, and that's more to my expectations for this purpose.
Try again with 0.1 µF and the original schematics.

#6

you are right, my bad,it was 0.1µF, 104 is a kind of ref ^^

#7

Hi, I have a WT588D-U with usb programmer which is working fine in keymode like this

When I try to wire it in Three mode or one line mode it does not work, no sound :frowning:

for three line mode
My wiring is like this

1001×1001 130 KB

(in the spec I’ve seen 470 ohm inline resistor but nothing more with or without the resistors)
the code is the one I’ve found here:

for one line mode
Same wiring but only data is used
and the one line code function is here:

void WT588D_Send_Command(byte addr) {
   digitalWrite(WT588D_SDA, LOW);
   delay(5);

   for(int i = 0; i < 8; i++)  {
       digitalWrite(WT588D_SDA, HIGH);
       if(bitRead(addr, i)) {
           delayMicroseconds(600);
           digitalWrite(WT588D_SDA, LOW);
           delayMicroseconds(200);
       } else {
           delayMicroseconds(200);
           digitalWrite(WT588D_SDA, LOW);
           delayMicroseconds(600);
       }
   }

   digitalWrite(WT588D_SDA, HIGH);
   delay(100);
}

Nothing more in one line mode

According to the spec my pin data is
P03 the second one bottom right when usb plug is up.
I’ve check the correct setting of my project (one line mode/ three line mode)

Maybe I’ve burned the IO input pin of the WD as I’ve connected the arduino directlyy to it? But they are still working in keymode…

any idea?

#8