fw/: added image sweep (completely untested)

fw/Makefile

@@ -30,7 +30,7 @@ OBJCOPY = $(AVR_PREFIX)objcopy
 #OBJDUMP = $(AVR_PREFIX)objdump
 SIZE = $(AVR_PREFIX)size
 
-OBJS = $(NAME).o dispatch.o hash.o reset.o $(COMMON_OBJS)
+OBJS = $(NAME).o dispatch.o hash.o reset.o sweep.o $(COMMON_OBJS)
 BOOT_OBJS = boot.o flash.o fw.o $(COMMON_OBJS)
 COMMON_OBJS = rf.o spi.o
 

fw/antorcha.c

@@ -14,13 +14,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include <avr/io.h>
-#define F_CPU   8000000UL
-#include <util/delay.h>
-
-#include "io.h"
 #include "rf.h"
 #include "dispatch.h"
+#include "sweep.h"
 
 
 static const struct handler *protos[] = {
@@ -39,6 +35,8 @@ int main(void)
 	 * It has also brought up RF and the underlying SPI.
 	 */
 
+	sweep_init();
+
 	while (1) {
 		got = rf_recv(buf, sizeof(buf));
 		if (got > 2)

fw/io.h

@@ -16,6 +16,20 @@
 #include <avr/io.h>
 
 
+#define	LED_A1	C, 0
+#define	LED_A2	C, 1
+#define	LED_A3	C, 2
+#define	LED_A4	C, 3
+#define	LED_A5	C, 4
+#define	LED_A6	C, 5
+#define	LED_A7	D, 0
+#define	LED_A8	D, 1
+
+#define	LED_B1	D, 2
+#define	LED_B2	D, 3
+#define	LED_B3	D, 4
+#define	LED_B4	B, 6
+#define	LED_B5	B, 7
 #define	LED_B6	D, 5
 #define	LED_B7	D, 6
 #define	LED_B8	D, 7

fw/proto.h

@@ -13,6 +13,9 @@
 #ifndef PROTO_H
 #define	PROTO_H
 
+#include <stdint.h>
+
+
 #define	PAYLOAD		64	/* most messages use a fixed 64 bytes payload */
 
 enum pck_type {
@@ -27,4 +30,35 @@ enum pck_type {
 	PARAM_ACK	= 9,	/* parameter upload acknowledgement */
 };
 
+
+struct params {
+	/* Timer ticks */
+
+	uint16_t clkT_period;		/* Timer period */
+
+	/* Accelerator thresholds */
+
+	uint16_t xa_high;		/* X acceleration high threshold */
+	uint16_t xa_low;		/* X acceleration low threshold */
+
+	/* Pixel offsets (in image) */
+
+	uint8_t	px_fwd_img_first;	/* first column in forward move */
+	uint8_t	px_fwd_img_end;		/* last column in forward move */
+	uint8_t	px_bwd_img_first;	/* first (high) col. in backward move */
+	uint8_t	px_bwd_img_end;		/* last (low) column in backward move */
+
+	/* Timer periods, for imaging */
+
+	uint16_t tp_fwd_start;		/* forward image start */
+	uint16_t tp_bwd_start;		/* backward image start */
+	uint8_t tp_fwd_pix;		/* pixel size in forward move */
+	uint8_t tp_bwd_pix;		/* pixel size in backward move */
+
+	/* Timer periods, for estimation */
+
+	uint16_t tp_fwd;		/* forward half-period */
+	uint16_t tp_bwd;		/* backward half-period */
+};
+
 #endif /* !PROTO_H */

fw/sweep.c

@@ -0,0 +1,145 @@
+/*
+ * fw/image.c - Image sweep
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#include "sweep.h"
+
+
+struct line image[MAX_LINES];
+
+static uint32_t t_sw;		/* cumulative number of timer ticks in sweep */
+
+static uint16_t wait_periods;	/* number of periods to wait before image */
+static uint16_t wait_period;	/* ticks in wait period */
+static uint16_t wait_short;	/* ticks to wait after periods */
+
+static uint16_t pixel_ticks;	/* number of ticks per pixel */
+static const struct line *curr_line;
+static const struct line *end_line;
+static bool forward;
+
+
+ISR(TIMER1_OVF_vect)
+{
+	/* update the sweep time */
+
+	t_sw += OCR1A;
+
+	/* if at the end of the image, only update the time */
+
+	if (curr_line == end_line)
+		return;
+
+	/* wait before starting the image */
+
+	if (wait_periods) {
+		if (!--wait_periods)
+			OCR1A = wait_short;
+		return;
+	}
+
+	/* output the next line */
+
+	PORTB = (PORTB & 0x3f) | (curr_line->cb & 0xc0);
+	PORTC = curr_line->cb;
+	PORTD = curr_line->d;
+
+	/* move to the next line */
+
+	if (forward)
+		curr_line++;
+	else
+		curr_line--;
+
+	/* wait until the next pixel (or slow down if we're done) */
+
+	if (curr_line == end_line)
+		OCR1A = 0xffff;
+	else
+		OCR1A = pixel_ticks;
+}
+
+
+void image_sweep(const struct sweep *sweep)
+{
+	TCCR1B = 0;	/* stop the timer */
+
+	cli();
+
+	/* shut down all the LEDs, in case we're still in a sweep */
+
+	PORTB &= 0x3f;
+	PORTC = 0;
+	PORTD = 0;
+
+	/* image pointers and sweep direction */
+
+	forward = sweep->forward;
+	if (forward) {
+		curr_line = image+sweep->left;
+		end_line = image+sweep->right+1;
+	} else {
+		curr_line = image+sweep->right;
+		end_line = image+sweep->left-1;
+	}
+
+	/* timing parameters */
+
+	wait_periods = sweep->wait_ticks >> 16;
+	if (wait_periods) {
+	 	wait_short = sweep->wait_ticks;
+		wait_period = 0xffff;
+
+		/*
+		 * Make sure we have plenty of time to update OCR1A after an
+		 * interrupt.
+		 */
+		if (wait_short < 256) {
+			wait_period -= 128;
+			wait_short += wait_periods << 7;
+		}
+		OCR1A = wait_period;
+	} else {
+	 	OCR1A = sweep->wait_ticks;
+	}
+
+	/* prepare the hardware timer */
+
+	t_sw = 0;		/* reset the time */
+	TCNT1 = 0;
+	TIFR1 = 1 << TOV1;	/* clear interrupt */
+	
+	/* start the timer */
+
+	TCCR1B =
+	    1 << WGM13 |	/* WG Mode 15, continued */
+	    1 << WGM12 |
+	    1 << CS11;		/* clkIO/8 */
+}
+
+
+void sweep_init(void)
+{
+	TCCR1A =
+	    1 << WGM11 |	/* WG Mode 15 (Fast PWM to OCR1A) */
+	    1 << WGM10;
+
+	TCNT1 = 0;
+
+	TIMSK1 = 1 << TOIE1;	/* enable timer interrupts */
+}

fw/sweep.h

@@ -0,0 +1,45 @@
+/*
+ * fw/sweep.h - Image sweep
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef SWEEP_H
+#define	SWEEP_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+
+#define	MAX_LINES	100
+
+
+struct line {
+	uint8_t d;		/* port D0-D7 */
+	uint8_t cb;		/* port C0-C5, B6-B7 */
+};
+
+
+struct sweep {
+	uint32_t wait_ticks;	/* number of ticks to wait before image */
+	uint16_t pixel_ticks;	/* number of ticks per pixel */
+	uint8_t left;		/* leftmost line of image */
+	uint8_t right;		/* rightmost line of image */
+	bool forward;		/* direction of movement */
+};
+
+
+extern struct line image[MAX_LINES];
+
+
+void image_sweep(const struct sweep *sweep);
+void sweep_init(void);
+
+#endif /* !SWEEP_H */