X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=arducontrol%2Fs88.c;fp=arducontrol%2Fs88.c;h=1ce574059fd848082d078e34033efeaa19abdd4d;hb=3bbca0dcce53ff9e2cdaa3d39ae18afcbf627f9d;hp=0000000000000000000000000000000000000000;hpb=cd913ccb15a71d793ccd701d3ab8b39a0efeb23a;p=model-railway-devices.git

diff --git a/arducontrol/s88.c b/arducontrol/s88.c
new file mode 100644
index 0000000..1ce5740
--- /dev/null
+++ b/arducontrol/s88.c
@@ -0,0 +1,110 @@
+#include <avr/io.h>
+#include "interface.h"
+#include "ringbuffer.h"
+#include "s88.h"
+#include "serial.h"
+#include "timer.h"
+
+#define RESET PORTD4
+#define LOAD PORTD5
+#define CLOCK PORTD6
+#define DATA PIN7
+#define BIT(x) (1<<(x))
+
+volatile uint8_t s88_read_count = 0;
+uint8_t s88_read_bit = 0;
+volatile uint8_t s88_read_phase = 0;
+uint8_t s88_data = 0;
+RINGBUFFER(s88_buffer, 8);
+uint8_t s88_out_index = 0;
+
+void s88_init(void)
+{
+	DDRD = (DDRD&0x0F)|0x70;
+	PORTD &= 0x0F;
+
+	timer_start_hz(0, 80000, 1);
+}
+
+void s88_check(void)
+{
+	// Only send one packet per check to avoid blocking
+	if(ringbuffer_fill(s88_buffer)>0)
+	{
+		uint8_t reply[3];
+		reply[0] = S88_DATA;
+		reply[1] = s88_out_index++;
+		reply[2] = ringbuffer_pop(s88_buffer);
+		interface_send(reply, sizeof(reply));
+	}
+}
+
+uint8_t s88_command(const uint8_t *cmd_buf, uint8_t cmd_length)
+{
+	if(cmd_buf[0]==S88_READ)
+	{
+		if(cmd_length!=2)
+			return LENGTH_ERROR;
+
+		while(s88_read_count || s88_read_phase) ;
+
+		s88_out_index = 0;
+		s88_read_phase = 0xF0;
+		s88_read_count = cmd_buf[1];
+	}
+	else
+		return INVALID_COMMAND;
+
+	return COMMAND_OK;
+}
+
+static inline void s88_tick(void)
+{
+	if(s88_read_phase==0)
+	{
+		if(!s88_read_count || ringbuffer_space(s88_buffer)==0)
+			return;
+
+		PORTD |= BIT(CLOCK);
+	}
+	else if(s88_read_phase==1)
+	{
+		uint8_t bit = (PIND>>7)&1;
+		s88_data = (s88_data<<1)|bit;
+		++s88_read_bit;
+		if(s88_read_bit==8)
+		{
+			ringbuffer_push(s88_buffer, s88_data);
+
+			--s88_read_count;
+			s88_read_bit = 0;
+		}
+	}
+	else if(s88_read_phase==2)
+		PORTD &= ~BIT(CLOCK);
+	else if(s88_read_phase>3)
+	{
+		if(s88_read_phase==0xF0)
+			PORTD |= BIT(LOAD);
+		else if(s88_read_phase==0xF4)
+			PORTD |= BIT(CLOCK);
+		else if(s88_read_phase==0xF6)
+			PORTD &= ~BIT(CLOCK);
+		else if(s88_read_phase==0xFA)
+			PORTD |= BIT(RESET);
+		else if(s88_read_phase==0xFC)
+			PORTD &= ~BIT(RESET);
+		else if(s88_read_phase==0xFF)
+		{
+			s88_data = (PIND>>7)&1;
+			++s88_read_bit;
+			PORTD &= ~BIT(LOAD);
+		}
+		++s88_read_phase;
+		return;
+	}
+
+	s88_read_phase = (s88_read_phase+1)&3;
+}
+
+TIMER_SET_CALLBACK(0, s88_tick)