(C) 2011 Theodore Wahrburg
 email: ted.wahrburg (At) gmail (dot) com
All software and associated hardware comes with no warranty. USE AT YOUR OWN RISK. Free for all non-commercial use. Plese provide proper credit if code is used in future project.

Original post:
https://familab.org/2011/12/dimmable-ac-light-box/


PIC16F628 --
Communicate with UART @ 19200 Baud 8,1,Null 


The UART Protocol to control light dimming is composed of 12 bytes. 
A start byte, 10 bytes for channels, and an end byte which is an xor'ed checksum of the previous 10 channels. 
It is to be noted that regardless if the PIC device supports 10 channels, 10 channels must be provided in protocol.
A Start Byte is composed of the value of '1', and it is reserved for use as a Start Byte; The only other exception is as a checksum value, where it is allowed.
Else, if '1' is used as a Channel Value, it will force the PIC to interpret the byte as a Start Byte. This is to allow a quick correction in the event of a UART error.

-- Protocol Breakdown --
Byte 01: Start Byte; Use '1'
Byte 02: Channel 01; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 03: Channel 02; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 04: Channel 03; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 05: Channel 04; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 06: Channel 05; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 07: Channel 06; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 08: Channel 07; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 09: Channel 08; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 10: Channel 09; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 11: Channel 10; Use Value from 0 to 255 to specify intensity. (do not use start byte value of '1')
Byte 12: Checksum; Determinded by xor'ing Channels 01 to 10.