how to decode serial data with 8051

[phtsai]

I try to using the 8051 to decode the serial data send from a PTZ keyboard (using Pelco D / P protocol)

The data transmitted from the keyboard will be something like this:

ff 01 00 04 20 00 25 (This will make the camera to pan left at moderate speed)

"synch byte" - ff
"address byte" - 01
command 1 byte - 00 (no action)
command 2 byte - 04 (pan camera to the left)
data 1 byte - 20 (pan at moderate speed)
data 2 byte - 00 (no additional data)
checksum - 25 (add contents of bytes 2 through 6)


Can anyone provide me information on how to use 8051 to decode the serial data.

 

[IanP]

The best option would be to use RI&TI interrupt with Rx buffer and define special bit for each byte as it was suggested in this example:

If you find it suitable come back ..

Regards,
IanP

 

[vijaya_narayana]

i think u can have base value for just compare the values so that u can manuplate the camera.It is berret to use serial interrupts for getting the data