Problem reading Data o/p from DTMF decoder with PIC 16F84

[neurostatic]

dtmf 16f84a

Hey people, i've connected a MITEL 8870 DTMF decoder to port b of my PIC.When i transmit a DTMF the decoder should give 5V on its data vaild
and then the same voltage on it data outputs but i'm only getting 0.75 V on these outputs of the decoder.
When i remove the pic and test the DTMF it works fine giving 5V on DV and data outputs.
Would anyone know why this voltage drop is occuring with the pic in.
The PIC pins are configured to be inputs RB0-3.
:?

 

[C-Man]

dtmf decoder pic

Maybe you can post your code here, might be a problem with a misconfigured I/O pin of your pic.

Also post which pin of the dtmf chip is connected to which pin of your pic.

best regards

 

[pico]

pic dtmf decoder

Check the resistance of the pic pin.

 

[cozturk]

16f84 dtmf

There was an error in the schematic of 8870 (kt3170) datasheet. I spent 1 month for this error.

 

[neurostatic]

dtmf pic

C-Man I'll get that done as soon as i can bit busy at the mo only checking in cheers

PICO how do i check the res of an idividual pin must the pic b taken out of circuit or left in and powered up?

Cozturk What was the error u found on the datasheet it may help me.

Thanks all.

 

[cozturk]

dtmf decode pic

It was about RC circuit. for output delaying. 2 sample circuit different. So you must connect RC to true pins! Look 16, 17, 18 pins

 

[mbyka]

dtmf decoder with pic

https://www.qsl.net/yo5ofh/pic/dial_alarm_circuit/dial_alarm_circuit.htm
https://www.qsl.net/yo5ofh/pic/tonef84/
**broken link removed**

**broken link removed**
https://wiredworld.tripod.com/tronics/remote_control.html
http://techtrain.microchip.com/masters2003/(fg5v5a45ntto1o554knecb45)/masters2003-CD/classes/729/DTMFDetectorSim.zip
http://techtrain.microchip.com/masters2003/(fg5v5a45ntto1o554knecb45)/masters2003-CD/classes/729/729.htm