Suggestions for Sound chip/design for T3.6 - similar capabilities of Propshield

[KurtE]

Suggestion for Simple sound setup for Teensy 3.5/3.6, but maybe also 3.2....

As many of you can probably tell, I like playing around with building my own boards, that I threaten to put into a robot and sometimes they actually make it on one. I typically like to have some form of sound generation on the board, as I typically like to have some form of audio feedback when I am running the robot. Typically not very complicated, but simple beeps, to acknowledge when a button has been pressed on the remote control or some form of alert when the battery power is getting low. On many of these earlier boards I put on simple RC circuit with buzzer and did my own version of sound command.

However with some of my Linux based boards, I have extended the sound a little bit by using things like Espeak (or ROS festival), and so for example when I choose a new walking gait, it might tell me what gait was selected.

What I think I want is probably the capabilities of the prop wit-out board, as I actually also have support on my current board for neopixel or APA102 like LEDS. But would be nice to have it on my main board, Thought about simply using the prop shield, but that would cover over some of the internal pins, like USB host pins.

I thought about using the same chip as is used in the prop shield: LM48310, but I think it is too small for me to personally hand solder.
Wish they had a larger version of it.

On a current board, I am trying to use an: LM4862M, but I think I screwed up something, either on the circuit itself or my parts or my soldering... Anyway when I try using it, no sound, and when it is enabled, I feel the speaker heating up...



Suggestions? Maybe I should try the setup that Frank has on the flexboard? Is the only source of them from Ebay?

Thanks

 

[Frank B]

Maybe I should try the setup that Frank has on the flexboard? Is the only source of them from Ebay?

It's cheaper than anything i could build myself.. the space on the PCB costs, too
I bought my amplifiers from alieepress- but i guess, there are other, better sources (but likely for more US$)

 

[Pazi]

You have forgotten the line with 20k resistor between pins 4 and 5?

 

[KurtE]

Yep - Looks like it... WIll be hard to retro fit this board, may have to build second one... Now that I have stackable headers, next one I will build such that I can remove the processor...

 

[KurtE]

Quick update:

I used one of the boards I had not built yet, and just assembled the Audio stuff, I then soldered a 22k Resistor across those two pins. I did not have a 20 in the sparkfun kit.. Yeah I know I could have used two 10K, but for this experiment I thought I would take it easy.

I then jumper-ed stuff over from the T3.6 beta board and tried it. I am not getting any output with Talkie...
I added in my pinMode(39, OUTPUT), digitalWrite(39, LOW); (Opposite of prop shields chip).

Has anyone tried Talkie with Propshield and T3.6 yet?

I was not seeing much on the Logic Analyzer, so I tried, doing my own simple app to see if anything works:

void setup() {
  pinMode(39, OUTPUT);
  digitalWrite(39, LOW);
}
int out_val = 0;
int incr = 4;
void loop () {
  analogWrite(A21, out_val);
  out_val += incr;
  if (out_val >= 256)
    incr = -4;
  if (out_val <= 0)
    incr = 4;  
  
}

Which made very annoying noise.


I then modified the ToneSweep analog sample. Changed to AudioOutputAnalog, removed the other object.. and downloaded and I am getting a pretty good output.

Note: on the PJRC propshield page it mentioned to get louder, to add line:
dac1.analogReference(EXTERNAL); // much louder!

But on T3.6 at least this shows up as dacl was not declared in this scope

But the good news is I think this sound chip can work. But next question will be to myself, is build a board with this jumper or order some new ones fabricated, that also include a few other fixes like more etch to the AX servo power pins... Also if I do a new board should I try to use AGND to the chip instead of simple ground...

More playing to do...

 

[defragster]

Yes, Talkie on Prop shield was made to work - By Frank - who located the moved DAC pin early in the beta. Not sure if I indexed it in post 8? I suppose the FIX got pulled in ? Frank posted the needed change and I found it to work.

Follow this : K66-Beta-Test

 

[KurtE]

It looked like the fix was in. Will try again. Was trying at 180mhz...
Update: Me Bad - I had a private copy of Talkie in my Arduino/libraries folder... Removed it and now appears to work

Also update to above: dac1.analogReference(EXTERNAL); // much louder!
Needs to be changed to the name of the object: AudioOutputAnalog has

 

[defragster]

Nice Kurt. Opps - IIRC - that means at least one sample needs updated to specify dac1 conditionally - <edit> didn't see one as far as I looked?

BTW: analogWrite(A21, nextPwm); in Talkie means DAC0 right :: dac0.analogReference(EXTERNAL);