terom@65: #include <util/delay.h>
terom@65: 
terom@65: // DMX
terom@98: #define DMX_DDR     DDRD
terom@98: #define DMX_PORT    PORTD
terom@98: #define DMX_DATA    2
terom@65: 
terom@65: // baud rate: 250k = 4µs / bit
terom@65: #define DMX_BAUD    (250 * 1000)
terom@65: #define DMX_US      4
terom@65: 
terom@65: // CPU cycles / bit: 64 @ 16Mhz
terom@65: #define DMX_CYCLES  (F_CPU / DMX_BAUD)
terom@65: 
terom@65: void dmx_init ()
terom@65: {
terom@65:     // dmx data out: idle (high)
terom@65:     sbi(&DMX_PORT, DMX_DATA);
terom@65:     sbi(&DMX_DDR, DMX_DATA);
terom@65: }
terom@65: 
terom@65: static inline void dmx_high ()
terom@65: {
terom@65:     sbi(&DMX_PORT, DMX_DATA);
terom@65: }
terom@65: 
terom@65: static inline void dmx_low ()
terom@65: {
terom@65:     cbi(&DMX_PORT, DMX_DATA);
terom@65: }
terom@65: 
terom@65: #define dmx_pause(bits) _delay_us((DMX_US * bits))
terom@65: 
terom@65: static void dmx_break ()
terom@65: {
terom@65:     // break
terom@65:     dmx_low();
terom@65:     dmx_pause(22);
terom@65: 
terom@65:     // mark-after-break (MAB)
terom@65:     dmx_high();
terom@101:     dmx_pause(3); // min 2, recommended 3
terom@65: }
terom@65: 
terom@65: #include "dmx_frame.c"
terom@65: 
terom@101: /*
terom@101:  * Send out a full DMX packet, including the start-code frame and a frame for each channel given.
terom@101:  *
terom@101:  * Uses 3-bit mark-times between frames, since some fixtures don't seem happy with 2-bit mark-times.
terom@101:  */
terom@66: static void dmx_packet (byte count, byte *out)
terom@65: {
terom@65:     dmx_break();
terom@65:     dmx_frame(0);
terom@101:     dmx_pause(1); // MTBF 2+1 = 3
terom@65: 
terom@66:     for (byte i = 0; i < count; i++) {
terom@66:         dmx_frame(out[i]);
terom@101: 
terom@101:         // MTBF 2+1 = 3
terom@101:         dmx_pause(1);
terom@66:     }
terom@65: }