ISD1700 series Winbond chipcorder

[rickeybell]

I have constructed a very rudimentary Jeopardy machine for competitions during in-services at our EMS agency. It has four controllers going to a simple PIC controlled box that lights the appropriate LED’s for three seconds while creating a buzzer that is different for each team. I have some additional upgrades planned for the unit.

1. Add voice capabilities for each team’s buzzer.
2. Add wireless to a couple of controllers
3. Make the controllers touch sensitive so there are no switches.
4. Add a Led or LCD indicator to each controller so the team knows that they have buzzed in first.

I have started on the voice item first. I have received a Winbond ISD1750 voice chip. It allows either SPI interfacing or old fashion push buttons. I am prototyping on an stand alone circuit with the button controls, small output speaker, input line, etc. I wired the unit per the pin outs on the datasheet for the chip. If I hold the FT (feed through) button and pass a sound to the chip through the audio in jack, it feeds the sound to the speaker like it is supposed to. If I hold the REC button the led turns on like it is recording; however, when I momentarily press play I get nothing but a quick flash on the led. If I hold play I get a buzzing sound. The erase seems to work erasing the blank recordings.

I see a lot of mention of needing chip programmers on the ISD devices. The data sheets never even refer to needing a recorder. Can these chips be used for my purpose? I am also having trouble finding actual instructions on the operation of the chip. I have looked at the briefs and datasheets.

Any suggestions? I am a bit surprised that I am having issues even recording simple sound.

Thank everyone for their help,

Rickey Bell, Paramedic

[wb6sjd]

Hi Rickey,

If you use the Mic input, it will work. A simple condenser mic (available at Radio Shack) will do fine.

If you need to use the AnaIn (pin9) input, then FT (pin22) must be held low during recording. It will then record from the analog input.

The ISD2500 series was much easier to use in pushbutton mode, but it has been discontinued.

The Winbond website and the ISD1700 datasheet frequently say "For technical details, please refer to the Design Guide". That is NOT the "AN-CC1002 Design Considerations for ISD1700 Family.pdf" document that is available on their website! In order to get the "Design Guide" (I1700 Design Guide Rev 1.1.pdf) I had to email them and request it. That is the only document I've found that bothers to tell you that the devices come from the factory with the AnaIn input and the Aux (Voltage) output disabled in pushbutton mode.

In order to reprogram the device's analog path configuration, you need to use the SPI interface. If you need more info on that, or have any other questions, let me know.

- Mike

[rickeybell]

Thanks, I have emailed the support people for the document. I will give it a try later, I will have to build the resistor network it calls for to use the mic. Shouldn't be much trouble. Do you have any code you can send me as an example for the SPI interface? PM or post is fine.

Thanks Again.

[peterdeco1]

Hi Rickey. I found a very large improvement in microphone audio quality by changing the resistor values shown in the datasheet. It shows 3 - 4.7K resistors surrounding the microphone. The top one that connects to Vcc, change to 1K. The other 2, change to 10K. Where the 1K meets the 1st 10K, you see a 4.7uF cap. Use a 220uF. Perhaps it was my microphones preference, but it was just a standard electret mic.

[RFEFX]

For your application i have found this to do what you are trying to do. I am still trying to get the SPI working on this board though.

http://www.cowlacious.com/AudioProd.htm

Regards,
Gary D.

[ams0178]

Hello Rickey,

I am wondering if you could send me the documentation for the ISD1700 that the mfg sent you, [email protected]. I'm hoping to use SPI to communicate w/ the chip, but the datasheet via digikey seems more like a 2 page summary. I can't find anything that shows the SPI commands. How's your project coming. Fully integrate the chip?

Thanks, Alan