PIC Audio

[toofastdave]

Hi all,
I was wondering if anyone had any experience with using a PIC in an audio amplifier circuit where you speak into a microphone and the Audio amp boosts the audio and distorts it a little (to sound like it's coming out of a radio) and then when the audio is finished the PIC plays a small sound or one of two or three sounds after the audio is done. I am currently trying to buy a prefabbed board which wil do this... BUT the production on the boards is limited and the next batch won't be out for several months. I need it to add the finishing touches on my Stormtrooper Armor Suit. The unit basically amplifies the audio and then when you get done talking it plays a short static burst.. like white noise or squelch on a radio... Would be nice to build a home brew of this. Anyone have any ideas they would be willing to share?

Cheers,
-Dave

[skimask]

Hi all,
I was wondering if anyone had any experience with using a PIC in an audio amplifier circuit where you speak into a microphone and the Audio amp boosts the audio and distorts it a little (to sound like it's coming out of a radio) and then when the audio is finished the PIC plays a small sound or one of two or three sounds after the audio is done. I am currently trying to buy a prefabbed board which wil do this... BUT the production on the boards is limited and the next batch won't be out for several months. I need it to add the finishing touches on my Stormtrooper Armor Suit. The unit basically amplifies the audio and then when you get done talking it plays a short static burst.. like white noise or squelch on a radio... Would be nice to build a home brew of this. Anyone have any ideas they would be willing to share?
Cheers,
-Dave

Is there a push-to-talk button anywhere that you could hack into to trigger a PIC into making the sound for you? The 'push' would arm the PIC to make the sound, and after the 'push' has been held for X seconds, it would actually be armed, then the 'release' would trigger the PIC to make white noise for X ms.

[peterdeco1]

OK. I have a couple of ideas. Give me a few days to try this one for you. We use the ISD5008 voice recorder IC all the time. I have never tried this but I will check to see if I can modify a program to output the incoming audio directly to the speaker. If so, it's a piece of cake. Releasing the activate button will have the PIC set the ISD chip into playback mode and jump to a memory location that has a prerecorded sound effect (of your choice). If the ISD won't allow this, there is another route to go but at this point I have very limited experience with a new ISD chip the ISD1700 series. With this chip, the incoming audio automatically outputs through the speaker during record indicating you have reached the end of the memory array. In theory, the chip could be addressed purposely to the end of the array. Incoming audio outputs through the speaker. When the button is released, the PIC puts it into playback mode and jumps to a location with your prerecorded sound effect. Again, I just began dabbling with this device and, being a different animal than a '5008, may take LOTS of time figuring out this one. Again, give me a few days to try the '5008 way.

[toofastdave]

Is there a push-to-talk button anywhere that you could hack into to trigger a PIC into making the sound for you? The 'push' would arm the PIC to make the sound, and after the 'push' has been held for X seconds, it would actually be armed, then the 'release' would trigger the PIC to make white noise for X ms.

Naaw, it's all hands free. The unit has to be in the helmet and there is no way to constantly keep pushing a button...especially when you are talking, holding stuff (blasters) and moving around. The armor is pretty complicated and you can't have any wires showing anywhere. You have to interact with the people around you so it would be very distracting to have to keep pushing the button everytime.

OK. I have a couple of ideas. Give me a few days to try this one for you. We use the ISD5008 voice recorder IC all the time. I have never tried this but I will check to see if I can modify a program to output the incoming audio directly to the speaker. If so, it's a piece of cake. Releasing the activate button will have the PIC set the ISD chip into playback mode and jump to a memory location that has a prerecorded sound effect (of your choice). If the ISD won't allow this, there is another route to go but at this point I have very limited experience with a new ISD chip the ISD1700 series. With this chip, the incoming audio automatically outputs through the speaker during record indicating you have reached the end of the memory array. In theory, the chip could be addressed purposely to the end of the array. Incoming audio outputs through the speaker. When the button is released, the PIC puts it into playback mode and jumps to a location with your prerecorded sound effect. Again, I just began dabbling with this device and, being a different animal than a '5008, may take LOTS of time figuring out this one. Again, give me a few days to try the '5008 way.

Does this chip have a logic pin that indicates when it is receiving audio? If so, you could eliminate the switch and have the PIC monitor the login state instead of having a switch. The unit I am looking at doesn't have any switches except to program it... I'm not really asking anyone to build this for me but I don't have ANY experience with audio so a little help would be great! Maybe suggest a chip that could do something like this or a combination of chips. I know you mentioned the ISD series. I could DL some of the data sheets to look them over.

Thanks!
Dave

[Pic_User]

Hi Dave,

Do you have a substitute amplifier board that will amplify your voice? That part may be a little tough, to get a PIC to amplify audio.

If you have an amplifier board or could build / buy one, the PIC may be able to do the rest.
Instead of a mechanical push-button switch, the A/D input or the comparator input could be used to “trigger” on a preset level. Some times called “VOX” (voiced operated transmission), this is used for hands free transmitter control.

You could tap into the audio and allow an adjustable threshold (voice) level to tell the PIC to be ready to playback your sounds. When the level drops below the threshold for a programmed period of time that would tell the PIC to play the sound now.
In other words; the PIC senses you are talking and then, that you have stopped talking. So it plays the sound, into the audio amplifier.

You have to figure out how to get the sound you want out of the PIC.

Interesting project
-Adam-

[toofastdave]

Hi Dave,

Do you have a substitute amplifier board that will amplify your voice? That part may be a little tough, to get a PIC to amplify audio.

If you have an amplifier board or could build / buy one, the PIC may be able to do the rest.
Instead of a mechanical push-button switch, the A/D input or the comparator input could be used to “trigger” on a preset level. Some times called “VOX” (voiced operated transmission), this is used for hands free transmitter control.

You could tap into the audio and allow an adjustable threshold (voice) level to tell the PIC to be ready to playback your sounds. When the level drops below the threshold for a programmed period of time that would tell the PIC to play the sound now.
In other words; the PIC senses you are talking and then, that you have stopped talking. So it plays the sound, into the audio amplifier.

You have to figure out how to get the sound you want out of the PIC.

Interesting project
-Adam-

Adam,
Yes I was planning on using an external amp..not sure which one yet but using the A/D comparator sounds like a great idea! The noise I want the PIC to simulate is just static or the short squelch sound that you hear when you unkey a transmitter... Forgot to mention that the board I am trying to emulate is driving 8 ohm speakers... I think it's pushing like 8 watts at 12vdc.. It's actually pretty loud in the video that I watched.

I figured since I have PBP and Proton Plus that I should be able to beat the 105 pound sterling ($210.00us) price for the board if I build it myself. Like everyone else though, I just lack the time.. I'd buy the dang board if he had them available just to save myself the trouble.

-Dave

[b1arrk5]

Dave,
For something simple, take a look at Radio Shack catalog #277-1008, a little 9 volt powered audio amplifier, it runs about $14.00 US, and is in most of the stores. Then add part #276-1323, it's a little digital sound recorder. It holds up to twenty seconds of low fidelity audio. Record your squelch sound from a walkie talkie, or whatever onto the recorder board. Put a little microphone inside your helmet, wire a cord down to the PIC. Let the audio from the microphone go into the amplifier, now your voice will be 'distorted' by the little speaker in the amp. When you finish speaking, let the PIC trigger the little recorder board to play the recording. The recorder runs on 9volts too, and costs about $11.00.

I've used both of these items to put together a quick demonstration for a client, I fed the audio from the amp to a bigger speaker for better fidelity, and it worked great. The hardest part was soldering my PIC driver circuit onto the recorder printed circuit board to parallel the PLAY pushbutton, (it's a little button, and my eyes are old!)

Hope this helps,

Jerry.

[toofastdave]

Norm,
Thanks for the advice on the SPI setups...I'm back home from a long trip and will be sitting down to look at this in detail.

Jerry,
I am way past the point where I can say I'd be limited to that dollar amount... holy cow. I got an evaluation system for one of the ISD systems so I can play around with storage devices... and pics, caps, resistors.. the whole shebang... I am waaay above where I should be in the $$$$ department but if it works then it would be worth it for me. I am not one to try to save money when I am building something so...I end up spending way more than I should. I'll keep you guys posted on progress.

Thanks again!
Dave