ISD1700 help !!

[lerameur]

Hi,

I build the stand alone circuit for the ISD1750 Windbond chip. The circuit is pretty straight forward in the datasheet. I also seen a few threads in this forum talking about this chip. I was not been able to fix my problem.
I believe it is recording right, the flashes like it is suppose to. by once play is pushed I hear a buzzing & noise sound. But that is is only when I push, if I let go the button then nothing is heard. I use a similar microphone:
http://search.digikey.com/scripts/Dk...name=P11969-ND
Any Idea how I should go about to trouble shoot this?

ken

[RussMartin]

Okay, let's see what we can figure out.

Is the circuit you used the one shown in Example #1 under the section title TYPICAL APPLICATION CIRCUITS? The most recent data sheet

http://www.nuvoton.com/NR/rdonlyres/.../0/ISD1700.pdf

has it on page 16. (My copy of the manual has it on page 55.)

Have you also read the Design Guide? There's also an Application Note, AN-CC1002, that you may wish to look at.

How did you build the circuit? Is it on a breadboard or a printed circuit board?

[lerameur]

Hi,

I did the circuit opn page 16 yes, without the two optional part on pin 17 and 27. I used an 8 ohm speaker I bought for this experiment. As for the grounds, I used all the same ground. I did not know how to create different ground with a single power source.
thanks

ken

[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.