ISD1700 and microcontroller

[cdwurm]

Hey guys,
I am looking into using the ISD1700 to play four different messages based on 4 different negative triggers from a separate device, since in non SPI mode you can only play one recording, I know the only way to do this is through a microcontroller. I am relatively new to using microcontrollers and can only program a few basic things, I was wondering if someone could help me out in choosing an appropriate microcontroller to do this task and some tips on programing separate audio messages.
Thanks

 

[Nick C.]

There is the cheapest way, and then there is the quickest way. Cheapest way would be to pick a flavor of microcontroller ATMEL/PIC/etc, build a programmer, download the programming software, go through the steep learning curve of learning the ins and outs of getting it running.

If this is just a one-off or a prototype and you just want to get it done without turning it into a full-time job, I'd suggest just buying a Basic Stamp and going from there. I just took a quick look at the ISD1700 datasheet, and I wouldn't even bother trying to interface via SPI if it wasn't necessary. Since you are only playing four messages, but can only play stored messaged sequentially (like many of these ISD chips, this one was meant to be used in answering machines), I would think you could get away with just pulsing the PLAY and FWD lines.

I could see it going something like this with a Basic Stamp (or any other microcontroller).

1) Monitor your four inputs.
2) Input three is detected, so message three needs to be played.
3) Microcontroller pulses the PLAY line to start playback of the first recording, then quickly pulses the FWD line twice to play the third message. This all happens within a millisecond or two, so it should be seamless.
4) Lather. Rinse. Repeat.

A Basic Stamp makes something like this so trivial. You could breadboard and program something like this rather quickly. Your code would look something like this (been a while since I used the BS, but it's in the ballpark):

if input3=0 then gosub playmessage3 ' if input three is low, go to routine to play third message

playmessage3:

low PLAY ' low pulse on the PLAY line
high PLAY

low FWD ' two negative pulses on the FWD line
high FWD
low FWD
high FWD

return ' go back to checking your inputs

**broken link removed**

**broken link removed**​

 

[cdwurm]

Ohh,
I think I finally get it.

Does the fwd fast forward to the next message, or does it fast forward like a VCR fast forwarding a tape?

1 pulse to play would play message 1?
1 pulse to play and 1 pulse to fwd plays message 2?
1 pulse to play and 2 pulses to fwd plays message 3?
1 pulse to play and 3 pulses to fwd plays message 4?

Is this how it works?

How would I record the individual messages?

 

[Nick C.]

Is this how it works?

I haven't used this part (just the old ISD25xx's and ISD14xx's ages ago), but that's what I make out from the datasheet. I think a clearer term for 'forward' would have been 'next'.

Actually, when I went back to the datasheet, I realized I was looking at the sheet for the ISD1700A. I don't have the time right now to look into this at length, and don't know what (if any) differences there are between the 1700 and 1700A, but the ISD1700A datasheet goes into much more detail about the standalone button operations than the ISD1700 datasheet that I found.

http://www.datasheetcatalog.org/datasheets2/36/368701_1.pdf

 

[cdwurm]

Hey, it me again.

I got the isd17040 and I have been playing around with it. I found that when you press next it goes to the next message based on what the last message played was. I am trying to write a config using the PIC16F84 (since its the only one I am really familiar with) and I am getting stuck. I need to find a way it make it play a message based on a negative input but it will have to press the next button a certain number of times based on what the last message played was. I hope this makes sense.

Thanks