DTMF Problem Help Please

Status
Not open for further replies.

mgiro

Newbie level 1
Joined
Feb 21, 2011
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,289
Hi i am a student working on a DTMF remote control device. I am using CM8870 decoder and am using a TP5089 to generate my DTMF.

i am attaching the original schematic that i have found on web, but different DTMF generator chip that i am using. The transmitter side of the first schematic is being prototyped right now. So i have the generator and decoder breadboarded.

First problem is that when i turn on the CM8870 all inputs are high and i am assuming that they are latched. When i take my tone out from the DTMF generator and put it in the input of my decoder nothing occurs when i close a switch? I do not understand why there is nothing occurring. I would appreciate any insight on the situation or if anyone has tried something similar to this.
thanks
 

Attachments

  • 5.gif
    30 KB · Views: 89

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…