From 5a9f9a5932915a5752acc79a97b1f16982e3ec5a Mon Sep 17 00:00:00 2001
From: David Lamparter <equinox@diac24.net>
Date: Fri, 11 May 2012 01:53:08 +0200
Subject: dali: initial implementation

---
 dali.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 dali.c

(limited to 'dali.c')

diff --git a/dali.c b/dali.c
new file mode 100644
index 0000000..d53675b
--- /dev/null
+++ b/dali.c
@@ -0,0 +1,117 @@
+static uint16_t dali_word;
+static uint8_t dali_subctr, dali_state, dali_bit;
+static uint8_t dali_prevpin;
+
+ISR(TIMER0_COMPA_vect)
+{
+	uint8_t inv = 1, data;
+
+	TCNT0 = 0;
+
+	if (PIND & D_DALII) {
+		PORTD |= (1 << D_LED2);
+	} else {
+		PORTD &= ~(1 << D_LED2);
+	}
+
+	data = (PIND >> D_DALII) & 1;
+	if (dali_state == 0 && data) {
+		uart_puts("dali rxbegin\n");
+		dali_state = 17;
+		dali_subctr = 4;
+		dali_word = 1;
+	}
+
+	/* really simple CDR - resync clock on edge.
+	 * this is ABSOLUTELY neccessary. */
+	if (dali_state >= 16 && (dali_prevpin ^ data)) {
+		if (dali_subctr >= 2 && dali_subctr <= 5)
+			dali_subctr = 4;
+	}
+	dali_prevpin = data;
+
+	dali_subctr++;
+	dali_subctr &= 7;
+	if (dali_subctr)
+		return;
+
+	switch (dali_state) {
+	/* idle */
+	case 0:
+		return;
+
+	/* write */
+	/* 1 + 2: start bit */
+	case 1:
+		uart_puts("dali[");
+		uart_puthex(dali_word >> 8);
+		uart_puthex(dali_word & 0xff);
+		uart_puts("]\n");
+	
+		PORTD |= (1 << D_DALIO);
+		dali_state++;
+		return;
+	case 2:
+		PORTD &= ~(1 << D_DALIO);
+		dali_state = 4;
+		dali_bit = 0;
+		return;
+	case 4:
+		inv = 0;
+	case 5:
+		dali_state ^= 1;
+
+		data = (dali_word >> (15 - dali_bit)) & 1;
+		data ^= inv;
+		if (data)
+			PORTD |= (1 << D_DALIO);
+		else
+			PORTD &= ~(1 << D_DALIO);
+
+		if (inv)
+			dali_bit++;
+		if (dali_bit == 16)
+			dali_state = 6;
+		break;
+	case 6:
+		PORTD &= ~(1 << D_DALIO);
+		dali_state = 0;
+		uart_puts("dali sent\n");
+		return;
+
+	/* read */
+	case 16:
+		dali_word <<= 1;
+		dali_word |= 1 - data;
+		dali_state = 17;
+		if (dali_word & 0x1000) {
+			dali_state = 0;
+			dali_word >>= 3;
+
+			uart_puts("dali_rx ");
+			uart_puthex(dali_word & 0xff);
+			uart_puts("\n");
+		}
+		break;
+	case 17:
+		dali_state = 16;
+		break;
+	}
+}
+
+static void dali_init(void)
+{
+	PORTD |= (1 << D_DALII);
+	PORTD &= ~(1 << D_DALIO);
+
+	dali_subctr = 0;
+	dali_state = 0;
+	dali_prevpin = 0;
+
+	TCNT0 = 0;
+	OCR0A = 52;				// 8 MHz / 8 / 52 = 19230.
+	TIMSK0 = (1 << OCIE0A);
+	TIFR0  = (1 << OCF0A);
+	TCCR0A = 0;
+	TCCR0B = (0 << CS02) | (1 << CS01) | (0 << CS00); // 8 MHz / 8 = 1MHz
+}
-- 
cgit v1.2.1