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.
I’ve already build this one before, in stereo. simple to build. works cool.
for a mouth we want it to be symmetric… and I already found out that you can place 2 leds (or more) in serie on 1 output, without need to chance a resistor or something.
only 2 components.
for a extra effect, you can place a capacitor between - and pin 5. then the leds will slowly turn off one by one when silent / makes it less flashing.
when pin 9 connected to 5 volt, it will work in dot mode.
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…
OK, that rocks (IMO), so tweaks is about all I can suggest. Since Walter has eyes, you could go sideways and get a bit more resolution in the display of the mouth to give it more expressiveness (tight lipped whispers, open mouthed shouting for warnings, maybe even sneers by tapering). That’s all I got, unless you want to add an arm for a sock puppet (which means, that’s all I got ;^> ).
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.
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.
