Let's Make Robots!

Walter Needs a Mouth

We did this once with walter's old "eyes", now another round of brainstorming with his "mouth".

Walter needs a mouth. In the past I have used the "picaxe sound detector circuit"  modified a bit, going to a few blue LEDs. As a track was played (assume the track is speech) the leds would blink and change intensity according to the audio levels. This was ok, I guess... I think I might want to go to a "led bar-graph chip" with say, 8 to 10 segments. As he speaks, the bars could be lit --from the center -->out and with more bars showing as audio levels increase. I dunno.

Has anyone played with any "audio display" chips? EQ's and the like? I know there are some drivers out there that will probably do exactly what I want to do, I just have never played with them.


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Thank you everybody for all your conversation and suggestions. I have to admit, I had the bar-graph idea in my head going into this, and I really just needed to know what driver chip to use but in the end, you guys came through in spades.

I actually brainstormed on that latex-freak-of-nature mouth for a while.... Yeah... no.

The rest of everything was great!

I have parts on the way --should have the results of my efforts soon.

How does this looks?

Like the kitt voicebox as Rudolph says.

I already know how i will wire it up, will need 5 transisters because 6 leds on 1 pin will be too much. The center 4 leds does'nt need a transister as 2 leds on 1 pin in series will work fine.

Lower half of the pcb will be cut off.

I found this was going to work for me. I thought you might be interested...


I remember seeing one done with a mouth driven by a servo.



Talkie Walkie by Guibot.

I was looking for that one. You beat me to it :P


One version of the thing ezekiel posted, based off the Tengu, using a little AVR instead of an audio display chip.

Personally I'd go with a LM3914 wired up to look like K.I.T.T. :)

Chris if you are chasing idea's, this is how not to do it..


wtf? thats weird..

There are a few Arduino VU-meter projects out there. I was thinking of adapting the code to use it with a Tiny chip that has analog pins to read the "speech", enough digital pins to drive the LEDs and supports TWI so I can command it to do other cool effects like cylon eye for example. I wired on a perf board a Tiny861 but did not finish up the code for it. So MiniEric still has no working mouth, even though the LEDs are there. I would need to play with the scope to see how the speech signal sent to the amp looks like and tweak the code on a regular Arduino chip, then install the Tiny core files and the TWI Slave library and make it work already. If I only had time for everything I want to do...