X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=firmware%2Fs88w-t.c;fp=firmware%2Fs88w-t.c;h=e88a1f509eb6fc24aec4c4a8e05e83bce6a4fd7e;hb=af6a469f761ceec44e94bea5fe8e5345fd368966;hp=0000000000000000000000000000000000000000;hpb=fd3352aba49e455947bdcbfccc8a37e165564ba3;p=model-railway-devices.git

diff --git a/firmware/s88w-t.c b/firmware/s88w-t.c
new file mode 100644
index 0000000..e88a1f5
--- /dev/null
+++ b/firmware/s88w-t.c
@@ -0,0 +1,111 @@
+/* $Id$
+
+This file is part of the MSP Märklin suite
+Copyright © 2010  Mikkosoft Productions, Mikko Rasa
+Distributed under the GPL
+
+Firmware for wireless S88 transmitter module
+
+ATMega pinout:
+D0 - serial RX
+D1 - serial TX
+D2 - input 1
+D3 - input 2
+D4 - input 3
+D5 - input 4
+D6 - input 5
+D7 - input 6
+B0 - input 7
+B1 - input 8
+
+Inputs are pulled high by internal pull-up resistors.  Connect to GND to
+activate.
+*/
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#define BIT(n) (1<<(n))
+
+void send_state(void);
+void write_serial(uint8_t);
+uint8_t hexdigit(uint8_t);
+
+volatile uint8_t state = 0;
+
+int main()
+{
+	DDRD = 0x02;   // 00000010
+	PORTD = 0xFC;  // 11111100
+	DDRB = 0x20;   // 00100000
+	PORTB = 0x3F;  // 00111111
+
+	// 9600 baud, 8N1
+	UBRR0H = 0;
+	UBRR0L = 103;
+	UCSR0C = BIT(UCSZ00) | BIT(UCSZ01);
+	UCSR0B = BIT(RXEN0) | BIT(TXEN0);
+
+	// 0.5 Hz (CK/1024, TOP=31250)
+	TCCR1A = 0;
+	TCCR1B = BIT(WGM12) | BIT(CS12) | BIT(CS10);
+	OCR1AH = 122;
+	OCR1AL = 18;
+	TIMSK1 = BIT(OCIE1A);
+
+	sei();
+
+	while(1)
+	{
+		uint8_t i;
+		uint8_t input = 0;
+		uint8_t valid = 0xFF;
+
+		for(i=0; i<100; ++i)
+		{
+			uint8_t pins;
+
+			pins = ~((PIND>>2) | (PINB<<6));
+			if(i==0)
+				input = pins;
+			valid &= ~(pins^input);
+		}
+
+		input &= valid;
+		input |= state&~valid;
+
+		if(input!=state)
+		{
+			state = input;
+			send_state();
+		}
+	}
+
+	return 0;
+}
+
+ISR(TIMER1_COMPA_vect)
+{
+	send_state();
+}
+
+void send_state(void)
+{
+	write_serial(':');
+	write_serial(hexdigit(state>>4));
+	write_serial(hexdigit(state&0xF));
+}
+
+void write_serial(uint8_t c)
+{
+	while(!(UCSR0A&(1<<UDRE0))) ;
+	UDR0 = c;
+}
+
+uint8_t hexdigit(uint8_t n)
+{
+	if(n<10)
+		return '0'+n;
+	else
+		return 'A'+(n-0xA);
+}