From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 23 Oct 2013 21:36:44 +0000 (+0300)
Subject: Add support for S88 feedback modules
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=3bbca0dcce53ff9e2cdaa3d39ae18afcbf627f9d;p=model-railway-devices.git

Add support for S88 feedback modules
---

diff --git a/arducontrol/Makefile b/arducontrol/Makefile
index b520eb7..a7cb562 100644
--- a/arducontrol/Makefile
+++ b/arducontrol/Makefile
@@ -1,3 +1,3 @@
 include ../common/build.mk
 
-arducontrol.elf: adc.o interface.o monitor.o motorola.o output.o serial.o timer.o
+arducontrol.elf: adc.o interface.o monitor.o motorola.o output.o serial.o s88.o timer.o
diff --git a/arducontrol/arducontrol.c b/arducontrol/arducontrol.c
index 1c8cde9..8ec27ea 100644
--- a/arducontrol/arducontrol.c
+++ b/arducontrol/arducontrol.c
@@ -11,6 +11,12 @@ Connections for Pololu high-powered motor driver:
 D2 <-> DIR
 D3 <-> PWM
 
+Connections for S88 bus:
+D4 <-> RESET
+D5 <-> LOAD
+D6 <-> CLOCK
+D7 <-> DATA
+
 ADC connections:
 ADC0 - current sensor (adjusted for 185 mV/A, centered at Vcc/2)
 ADC1 - input voltage (adjusted for divisor of 11)
@@ -38,12 +44,14 @@ its data to the track can start.
 #include "interface.h"
 #include "monitor.h"
 #include "output.h"
+#include "s88.h"
 
 int main(void)
 {
 	output_init();
 	interface_init();
 	monitor_init();
+	s88_init();
 
 	sei();
 
@@ -51,6 +59,7 @@ int main(void)
 	{
 		interface_check();
 		monitor_check();
+		s88_check();
 	}
 
 	return 0;
diff --git a/arducontrol/commands.h b/arducontrol/commands.h
index 865405d..eae919c 100644
--- a/arducontrol/commands.h
+++ b/arducontrol/commands.h
@@ -13,6 +13,7 @@ enum Command
 	MOTOROLA_SPEED_DIRECTION = 0x13,
 	MOTOROLA_SPEED_FUNCTION = 0x14,
 	MOTOROLA_SOLENOID = 0x15,
+	S88_READ = 0x30,
 	COMMAND_OK = 0x80,
 	RECEIVE_OVERRUN = 0x81,
 	FRAMING_ERROR = 0x82,
@@ -21,7 +22,8 @@ enum Command
 	INVALID_VALUE = 0x85,
 	OVERCURRENT = 0xA0,
 	TRACK_CURRENT = 0xC0,
-	INPUT_VOLTAGE = 0xC1
+	INPUT_VOLTAGE = 0xC1,
+	S88_DATA = 0xD0
 };
 
 #endif
diff --git a/arducontrol/interface.c b/arducontrol/interface.c
index 96baba7..4064120 100644
--- a/arducontrol/interface.c
+++ b/arducontrol/interface.c
@@ -3,6 +3,7 @@
 #include "motorola.h"
 #include "output.h"
 #include "serial.h"
+#include "s88.h"
 
 volatile uint8_t recv_buf[32];
 uint8_t recv_head = 0;
@@ -83,6 +84,8 @@ uint8_t dispatch_command(const uint8_t *cmd, uint8_t length)
 	}
 	else if(type==1)
 		return motorola_command(cmd, length);
+	else if(type==3)
+		return s88_command(cmd, length);
 	else
 		return INVALID_COMMAND;
 }
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)
diff --git a/arducontrol/s88.h b/arducontrol/s88.h
new file mode 100644
index 0000000..b440ebe
--- /dev/null
+++ b/arducontrol/s88.h
@@ -0,0 +1,10 @@
+#ifndef S88_H_
+#define S88_H_
+
+#include <stdint.h>
+
+void s88_init(void);
+void s88_check(void);
+uint8_t s88_command(const uint8_t *, uint8_t);
+
+#endif