Sharing A Speaker With An DY-SV19T For MP3 Files And ESP32 For Tone

[_John_]

Hello, I have a project in which I'd like to use the DY-SV19T to play mp3 files and also use an ESP32 to play tones through the same speaker. When I hook them both up to the same speaker the DY-SV19T plays fine but the ESP32 doesn't play the tone.

I found if I put a 10ohm resistor between the - of the speaker and the ground of the ESP32 they both play fine. But when the DY-SV19T plays an MP3 file the resistor gets very hot quickly. I put several resistors in parallel equalling 10ohms which slows down the heat, but this isn't an ideal solution.

I hoping to get some insight into this problem here. Any ideas as to what the cause of this is or potential solutions would be greatly appreciated.

 

[Nigel Goodwin]

There are two pins on the DY-SV19T module RP_OUT and RP_IN, with a zero ohm resistor joining them together - if you remove the resistor you can insert a volume control in there.

I would suggest removing the zero ohm resistor and putting a fixed resistor (try 4.7K) between RP_OUT and RP_IN, and then feed the output from the ESP via another resistor to RP_IN (probably) - it's not very clear which is the input and which is the output? (due to the way the schematic shows a volume control connected). You can select the resistor from the ESP to give the relative volume you require - you might start at 47K, on the assumption that the signal level there is less than logic levels.

You can't just go bodging things to speaker outputs.

 

[_John_]

Hi Nigel,

Thanks for the response! The version of the DY-SV19T doesn't seem to have an RP_OUT or RP_IN. It looks like those pins were replaced with DACL and DACR. I also don't see any 0ohm resistors.

I'll attach a couple pictures.

Thanks again for the help!

 

[_John_]

I'm sorry, I made a mistake. I have the DY-SV17F, not the DY-SV19T. Sorry about the confusion.

 

[Nigel Goodwin]

That makes things more tricky then - but the input of the power amplifier is pin 4, which according to the datasheet for the LTK5128 is fed through a capacitor and a series resistor, you could try applying the output of the ESP to pin 4 via another capacitor and resistor, selecting the resistor to give the volume you require.

 

[_John_]

Thank you Nigel! I tried several configurations and the closest I could get was with a 10uf cap and 100k resistor. It still had some problems though and it was a pain soldering to the pin. I think my best bet is just to use a second speaker. Little 3w speakers are cheap anyway.

Thanks again! I appreciate your help!

 

[Nigel Goodwin]

Thank you Nigel! I tried several configurations and the closest I could get was with a 10uf cap and 100k resistor. It still had some problems though and it was a pain soldering to the pin. I think my best bet is just to use a second speaker. Little 3w speakers are cheap anyway.

Thanks again! I appreciate your help!

I wouldn't have soldered to the pin, I've have soldered to the existing resistor which connects to the pin (larger and easier) - you also don't need a 10uF, a 0.1uF should be fine.

 

[_John_]

I did try a 0.1uF cap with a 100k resistor and just got clicking sounds. Maybe I'm doing something wrong, I don't know.

I realized two speakers won't work either because I want to be able to send the audio to headphones too.

So, now I've decided to go with the mistake I made in my original post. I couldn't find the DY-SV19T here in the US but did find an SV19R which seems to be pretty much the same thing. I'll try your first suggestion of removing the resistor and putting a suitable volume resistor between RP_OUT and RP_IN. And then feed the ESP32 tone to the RP_IN via another resistor.

I'm hoping the same Arduino library will work with it.

Thanks again! Hopefully, this will do the trick.

 

[ronni39845]

Removing the resistor and installing a suitable volume resistor between RP_OUT and RP_IN should solve the click problem.

 

[_John_]

Hi ronni39843, the clicking problem was on the DY-SV17F. I made a mistake in my original post and called it a DY-SV19T. I appreciate the input though.

 

[_John_]

*Final Update*

I finally received my DY-SV19T. I did what Nigel recommended by removing the zero-ohm resistor. Which was so small I wasn't able to desolder it. So I just crushed it with some snips. I added a 10-ohm resistor between RP-IN and RP-OUT. And then a 2k ohm resistor between the tone output pin and RP-IN. And bingo! flawless audio.

Oddly enough, it works if I run it to RP-OUT also.

Anyway, one last big thank you to Nigel! You rock man!