ISD1700 help !!

[RussMartin]

Are you able to do an ERASE?

What value is the resistor you are using for Rosc on pin 20?

What does the LED do when you try to use the various functions?

[lerameur]

I dont know about erase, I dont hear comprehemble sounds, I will run some tests with the led tonight and will let you know my findings then.

k

[RussMartin]

Here is the application note:

http://www.nuvoton-usa.com/products/.../AN-CC1002.pdf

Right now, do not worry about sounds. Let us get the basic pushbutton functions to work by watching the LED.

[lerameur]

I hold down record and the led stays on until I unpress it. when I click on play there is a fast beeping, if I keep pushing on play, then I just hear multiple beeping and no led is turned on. when I click on erase the led flashes twice. when I hold down erase, the led flashes about 7 times.

I was once able to record and hear myself with a lot of noise. but I cannot reproduce this.

ken

[lerameur]

I forgot to mention that the led do not get lit when I click on any other button then the one mentioned above.

ken

[Agent36]

Hi Russ,
I was wondering if you could give me some advice on the 1700 series audio chips.
I have built a couple of proto crcuits using surface mount isd1740's in push button mode to start with. I can record, fast forward and play with out any problem.
I would like some tips on how to remove the pops at the start and end of the recording, along with the back ground hiss. Such as circuit design and layout to enable me to get the best from these chips. I have added a lm386 audio amp using an old winbond application sheet. I have both the main application sheets.

Any help to be very much appreciated.

kind regards Nick

P.s If any other forum members have some advice I would be please to hear from you too.

[RussMartin]

I would like some tips on how to remove the pops at the start and end of the recording, along with the back ground hiss.

Are you recording from an audio line input or from a microphone? You might try an "anti-pop" resistor across the input. To reduce the hiss, try a low-pass filter.

How are you configuring the APC register?

At what frequency are you running the ISD?

Such as circuit design and layout to enable me to get the best from these chips.

Pay especial attention to bypassing (lots of it!) and to power and ground routing.

I have added a lm386 audio amp using an old winbond application sheet.

I would like to see a copy of that old application sheet if possible.