# HG changeset patch
# User Tero Marttila <terom@fixme.fi>
# Date 1311720387 -10800
# Node ID 7c684d2416751eaa95905f598143a6e3f7d57620
# Parent  e6571a8040aed49c99e4c95ed3d3fad707f11264
dmx: initial try.. failed

diff -r e6571a8040ae -r 7c684d241675 Makefile
--- a/Makefile	Tue Jul 26 22:44:40 2011 +0300
+++ b/Makefile	Wed Jul 27 01:46:27 2011 +0300
@@ -9,7 +9,7 @@
 AD = avrdude
 ADFLAGS = -p $(AD_PART) -c $(AD_PROG) -b $(AD_BAUD) -P $(AD_PORT)
 
-PROG = console
+PROG = dmx
 
 all: $(PROG).hex
 
diff -r e6571a8040ae -r 7c684d241675 dmx.s
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dmx.s	Wed Jul 27 01:46:27 2011 +0300
@@ -0,0 +1,195 @@
+;;; vim: set ft=avr:
+
+.nolist
+.include "m168def.inc"      ; Same family as 328P
+.list
+
+
+;; Interrupt Vector
+.cseg
+.org 0x0000
+        rjmp        Main
+
+
+;; CPU cycles / second: 16 Mhz
+.set CPU_CYCLES = 16 * 1000 * 1000
+
+;; DMX baud raite: 250k
+.set DMX_BAUD = 250 * 1000
+
+;; CPU cycles / bit: 64
+.set DMX_CYCLES = CPU_CYCLES / DMX_BAUD
+
+;; DMX output por
+.set DMX_DDR = DDRB
+.set DMX_PORT = PORTB
+.equ DMX_DATA = PORTB3
+
+;; Debug LED
+.set LED_DDR = DDRB
+.set LED_PORT = PORTB
+.set LED_PIN = PINB
+.set LED_BIT = PORTB5
+
+;; Set up DMX output
+DMX_Init:
+    ; Setup output port
+        ; out
+        sbi     DMX_DDR, DMX_DATA
+
+        ; drive high
+        sbi     DMX_PORT, DMX_DATA
+
+    ; OK
+        ret
+
+;; Bitbang one DMX bit out
+;;  uses SREG/C to send
+DMX_Bit:
+    ; Output bit: 4 cycles
+        brcs    _dmx_bit_1
+        
+        cbi     DMX_PORT, DMX_DATA
+        rjmp    _dmx_bit_wait
+
+_dmx_bit_1:
+        sbi     DMX_PORT, DMX_DATA
+        nop
+
+_dmx_bit_wait:
+    ; Wait: 60 cycles
+        ; load: 1 cycle (offset by one less for brne)
+        ldi     r20, 6
+
+_dmx_bit_loop:
+        ; waste 8 cycles
+        nop
+        nop
+        nop
+        nop
+        nop
+        nop
+        nop
+        nop
+
+        ; loop: 1 + 2/1 cycles
+        ; 2/1 cycles
+        dec     r20
+        brne    _dmx_bit_loop
+       
+    ; OK
+        ret
+
+;; Break + MAB
+DMX_Break:
+    ; Break: 100 low bits
+        ldi         r21, 100
+
+_dmx_break_loop:
+        ; bitbang zero
+        clc
+        rcall       DMX_Bit
+        
+        ; count
+        dec         r21
+        brne        _dmx_break_loop
+
+    ; MAB: 4 high bits
+        ldi         r21, 4
+
+_dmx_break_mab:
+        sec
+        rcall       DMX_Bit
+
+        ; loop
+        dec         r21
+        brne        _dmx_break_mab
+
+    ; OK
+        ret
+
+;; Byte
+;;  r16: byte value
+DMX_Frame:
+    ; Start bit
+        sec
+        rcall       DMX_Bit
+
+    ; Data bits: 8
+        ldi         r21, 8
+        
+_dmx_frame_loop:
+        ; shift + send bit
+        lsl         r16
+        rcall       DMX_Bit
+
+        ; loop
+        dec         r21
+        brne        _dmx_frame_loop
+
+    ; Stop bits
+        clc
+        rcall       DMX_Bit
+        rcall       DMX_Bit
+    
+    ; OK
+        ret
+
+;; Send one value on all frames, continuously
+;;  r17: byte value
+DMX_Flood:
+_dmx_flood:
+    ; Break
+        rcall       DMX_Break
+
+    ; Start code
+        ldi         r16, 0
+        rcall       DMX_Frame
+
+    ; Channels
+        ; number of channels to send
+        ldi         r22, 100
+
+_dmx_flood_channels:
+        ; restore channel value
+        mov         r16, r17
+
+        ; send channel value
+        rcall       DMX_Frame
+
+        ; loop
+        dec         r22
+        brne        _dmx_flood_channels
+
+    ; OK; loop
+;sbi         LED_PIN, LED_BIT
+        rjmp        _dmx_flood
+
+
+;; Program main
+Main:
+; Initialization
+    ; Debug
+        sbi         LED_DDR, LED_BIT
+cbi         LED_PORT, LED_BIT
+
+    ; Stack
+        ldi         r16, high(RAMEND)
+        ldi         r17, low(RAMEND)
+        out         SPH, r16
+        out         SPL, r17
+
+
+    ; Init
+        rcall       DMX_Init
+
+sbi         LED_PORT, LED_BIT
+
+    ; Send; value
+        ldi         r17, 255
+        rcall       DMX_Flood
+
+_main_loop:
+        ; never returns..
+        rjmp        _main_loop
+
diff -r e6571a8040ae -r 7c684d241675 macros.inc
--- a/macros.inc	Tue Jul 26 22:44:40 2011 +0300
+++ b/macros.inc	Wed Jul 27 01:46:27 2011 +0300
@@ -2,6 +2,7 @@
 ; .ifndef _MACROS_INC_
 ; .define _MACROS_INC_
 
+;; Store to memory address
 .macro poke
 		.message	"No parameters"
 .endm