[goggles] / helper.asm

#include <xc.inc>
#include <pic12f1840.inc>

    OPT LIST

GLOBAL _rgb_sample
GLOBAL _rgb_bit
GLOBAL _rgb_byte
GLOBAL _rgbdata

GLOBAL _ws2811_send

PSECT mytext,local,class=CODE,delta=2

; send the whole pile of data
_ws2811_send:
    ; copy the led colour array into FSR0 for fast access
    MOVLW _rgbdata >> 8
    MOVWF FSR0H
    MOVLW _rgbdata & 0xFF
    MOVWF FSR0L


    ; load next byte from array into working reg
ws2811_nextbyte:
    MOVIW FSR0++
    MOVWF _rgb_sample
    MOVLW 8             ; reset bit count
    MOVWF _rgb_bit

ws2811_sendbit:
    ; you assume its a zero then test if its one
    MOVLW 0xC0 ;11000000B
    RLF _rgb_sample,f
    BTFSC CARRY
    MOVLW 0xF8 ; 11111000B

;    // wait until the buffer is empty
;ws2811_waitsend:
;    BTFSC PIR1, 3
;    BRA ws2811_waitsend

    ; send the bit
    BANKSEL (SSP1BUF)
    MOVWF BANKMASK(SSP1BUF)

    ; any more bits
    DECFSZ _rgb_bit,f
    BRA ws2811_sendbit

    ; any more bytes
    DECFSZ _rgb_byte,f
    BRA ws2811_nextbyte

    ; all done
    RETURN
Commit	Line	Data
	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