git://stoneship.org.uk / goggles / blame
| Commit | Line | Data |
|---|---|---|
| 5fc23db2 JM |
1 | #include <xc.inc> |
| 2 | #include <pic12f1840.inc> | |
| 3 | ||
| 4 | OPT LIST | |
| 5 | ||
| 6 | GLOBAL _rgb_sample | |
| 7 | GLOBAL _rgb_bit | |
| 8 | GLOBAL _rgb_byte | |
| 9 | GLOBAL _rgbdata | |
| 10 | ||
| 11 | GLOBAL _ws2811_send | |
| 12 | ||
| 13 | PSECT mytext,local,class=CODE,delta=2 | |
| 14 | ||
| 15 | ; send the whole pile of data | |
| 16 | _ws2811_send: | |
| 17 | ; copy the led colour array into FSR0 for fast access | |
| 18 | MOVLW _rgbdata >> 8 | |
| 19 | MOVWF FSR0H | |
| 20 | MOVLW _rgbdata & 0xFF | |
| 21 | MOVWF FSR0L | |
| 22 | ||
| 23 | ||
| 24 | ; load next byte from array into working reg | |
| 25 | ws2811_nextbyte: | |
| 26 | MOVIW FSR0++ | |
| 27 | MOVWF _rgb_sample | |
| 28 | MOVLW 8 ; reset bit count | |
| 29 | MOVWF _rgb_bit | |
| 30 | ||
| 31 | ws2811_sendbit: | |
| 32 | ; you assume its a zero then test if its one | |
| 33 | MOVLW 0xC0 ;11000000B | |
| 34 | RLF _rgb_sample,f | |
| 35 | BTFSC CARRY | |
| 36 | MOVLW 0xF8 ; 11111000B | |
| 37 | ||
| 38 | ; // wait until the buffer is empty | |
| 39 | ;ws2811_waitsend: | |
| 40 | ; BTFSC PIR1, 3 | |
| 41 | ; BRA ws2811_waitsend | |
| 42 | ||
| 43 | ; send the bit | |
| 44 | BANKSEL (SSP1BUF) | |
| 45 | MOVWF BANKMASK(SSP1BUF) | |
| 46 | ||
| 47 | ; any more bits | |
| 48 | DECFSZ _rgb_bit,f | |
| 49 | BRA ws2811_sendbit | |
| 50 | ||
| 51 | ; any more bytes | |
| 52 | DECFSZ _rgb_byte,f | |
| 53 | BRA ws2811_nextbyte | |
| 54 | ||
| 55 | ; all done | |
| 56 | RETURN |