View Full Version : cm8880 need help !!!

08-06-2008, 02:33 AM
hi all, new here and pretty new to the stamp also.. iv been tryin to play a little with dtmf for remote control applications via amateur radio, trouble is i cant get the thing to work!!! tried my own programs and those in app kit!! could anyone point me to a good explination of how this thing works.... should i be pulsing the system clock pin on the cm8880. reading the datasheet has only served to further confuse me.. i get the cra/crb but dont know if my data is getting there....

08-06-2008, 04:46 AM
www.parallax.com/dl/docs/cols/nv/vol1/col/nv7.pdf (http://www.parallax.com/dl/docs/cols/nv/vol1/col/nv7.pdf)

- Stephen

08-06-2008, 05:03 AM
thanks i'v tried this circut and code... DOA ... found that the code has some syntax issues .. i tried to fix it but no luck... this circut appears to be correct according to the datasheet and also the app kit.. i think the issue here was the code, guess ill try again tonight..

Mike Green
08-06-2008, 05:37 AM
The code was written for a BS1 and the BS2 Basic compiler has different syntax for declarations.

For "SYMBOL x = <constant>" use "x CON <constant>"
For "SYMBOL y = b#" (where # is a digit) use "y VAR byte"
For "SYMBOL z = w#" (where # is a digit) use "z VAR word"

There are a couple of other syntax differences for SERIN / SEROUT / LOOKDOWN / LOOKUP, maybe some others as well.

08-06-2008, 06:46 AM
thanks mike!!! the "var" i was missing... also had an issue with "let pins" changed to OUTL and getting somewhere.. still no dtmf tones but think it may be in the lookup... do i need to tell the stamp to convert dec to bin then OUTL ?? the syntax checket didnt catch the "digit = B2" .. B2 is a keyword havent looked it up yet but my guess is that i specifies BIT2 again thanks.. now to find the lookup issue

08-06-2008, 09:32 PM
Here is an application note that we used for the CM8880. I hope this helps.


Dave Andreae

Parallax Tech Support

08-07-2008, 04:09 AM
thank you dave , the bs2 code is exactly as mine looks , so i guess im getting it!!! after pulling the breadboard apart and starting over i got some life... kept hanging on the first digit!!! turns out a bad socket on the board in my data bus!! its really loose causing an intermiten short!!! guess its time to retire the old homework board.. too bad cause the stamp is still good.. time to shop parallax.com