PDA

View Full Version : ivrs



jeetbuz
06-28-2010, 09:21 AM
hi
i am making a ivrs project using cmd 8870 decoder ic, in single ended input mode.
i connected the pins as shown in the datasheet, but there is no output(std pin is high).
i have grounded 5,6 and oe is high too.
connected the silk wire from the headphones, 1 to input and other ground.
i am using a nokia phone and calling from a landline

plzz tell me wats wrong

wat shld be the voltage at input pin
it shows 2.5 and 0 when i connect the silk wires.

Ulhas
06-28-2010, 03:01 PM
Its very welly explained in first pages of this post

http://www.roboticsindia.com/showthread.php/3385-DTMF-decoder-based-bot-using-mobile

jeetbuz
06-30-2010, 01:28 AM
one question....
do i strip the wire from head set at the earpiece end ,or near the stereo pin??
does it make any diff.
coz i stripped it at the earpiece, it has 2 colored thin wires which i connected to the circuit and one to ground.
i even interchanged them, but all in vain .

Ulhas
06-30-2010, 08:10 AM
one question....
do i strip the wire from head set at the earpiece end ,or near the stereo pin??
does it make any diff.
coz i stripped it at the earpiece, it has 2 colored thin wires which i connected to the circuit and one to ground.
i even interchanged them, but all in vain .

No it won't make any difference But prefer using seperate male pin for taking output

jeetbuz
07-01-2010, 10:32 PM
sorry for asking a stupid questions:p
but what do u mean by "seperate male pin for taking output".

Ulhas
07-02-2010, 08:04 AM
Why don't you read this post from start

http://www.roboticsindia.com/showthread.php/3385-DTMF-decoder-based-bot-using-mobile