From 206eb4d59139127fa129dd7c62d29ef55490fa88 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Sun, 1 Jul 2012 19:40:01 -0300
Subject: [PATCH] clean up diagnostic more and make it more robust

A number of changes:
- don't enable interrupts, since they often cause hangs (not sure why)
- remove GND measurement
- wait 100 us between AMUX setup and start of conversion, to let input
  settle
- reduce delay between line setup and samping from 100 ms to 50 ms,
  for this is already sufficient
---
 fw/accel.c            |  7 +++++--
 fw/accel.h            |  2 +-
 fw/diag.c             | 16 +++++++++-------
 tools/ant-cl/ant-cl.c | 15 ++++++---------
 4 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/fw/accel.c b/fw/accel.c
index 018df41..99d0222 100644
--- a/fw/accel.c
+++ b/fw/accel.c
@@ -17,6 +17,8 @@
 
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#define F_CPU   8000000UL
+#include <util/delay.h>
 
 #include "io.h"
 #include "accel.h"
@@ -50,13 +52,14 @@ static inline void adcsra(bool start)
 }
 
 
-uint16_t measure_ref(bool gnd)
+uint16_t measure_ref(void)
 {
 	while (ADCSRA & (1 << ADSC));
 	adcsra(0);
 	ADMUX =
 	    1 << REFS0 |	/* Vref is AVcc */
-	    (gnd ? 15 : 14);	/* GND (0 V) or Vbg (1.1 V) */
+	    14;			/* Vbg (1.1 V) */
+	_delay_us(100);
 	adcsra(1);
 	while (ADCSRA & (1 << ADSC));
 	return ADC;
diff --git a/fw/accel.h b/fw/accel.h
index 06c8f0d..1813934 100644
--- a/fw/accel.h
+++ b/fw/accel.h
@@ -21,7 +21,7 @@
 extern void (*sample)(bool x, uint16_t v);
 
 
-uint16_t measure_ref(bool gnd);
+uint16_t measure_ref(void);
 void accel_start(void);
 
 #endif /* !ACCEL_H */
diff --git a/fw/diag.c b/fw/diag.c
index 30a81fb..a430f22 100644
--- a/fw/diag.c
+++ b/fw/diag.c
@@ -35,24 +35,26 @@ static bool failed;
 
 static void do_diag(void)
 {
-	uint8_t pkg[3+4*DIAG_SAMPLES] = { DIAG_ACK, 4, 0, };
+	uint8_t pkg[3+2*DIAG_SAMPLES] = { DIAG_ACK, 4, 0, };
 	uint8_t *p = pkg+3;
 	uint16_t v;
 	uint8_t i;
 
 	cli();
 	set_line(localize_line(tmp[0], tmp[1]));
-	_delay_ms(100);
+	_delay_ms(50);
 	for (i = 0; i != DIAG_SAMPLES; i++) {
-		v = measure_ref(1);
-		*p++ = v;
-		*p++ = v >> 8;
-		v = measure_ref(0);
+		v = measure_ref();
 		*p++ = v;
 		*p++ = v >> 8;
 	}
 	set_line(localize_line(0, 0));
-	sei();
+	/*
+	 * @@@ for some reason the firmware often hangs if we enable
+	 * interrupts here
+	 *
+	 * sei();
+	 */
 	rf_send(pkg, sizeof(pkg));
 }
 
diff --git a/tools/ant-cl/ant-cl.c b/tools/ant-cl/ant-cl.c
index 966c975..9788425 100644
--- a/tools/ant-cl/ant-cl.c
+++ b/tools/ant-cl/ant-cl.c
@@ -517,8 +517,7 @@ quit:
 /* ----- Diagnostics ------------------------------------------------------- */
 
 
-static void send_diag(struct atrf_dsc *dsc, uint16_t pattern,
-    uint16_t *gnd, uint16_t *v_bg)
+static void send_diag(struct atrf_dsc *dsc, uint16_t pattern, uint16_t *v_bg)
 {
 	uint8_t payload[PAYLOAD];
 	int got, i;
@@ -553,22 +552,20 @@ static void send_diag(struct atrf_dsc *dsc, uint16_t pattern,
 	}
 	if (verbose)
 		write(2, "\n", 1);
-	for (i = 0; i != DIAG_SAMPLES; i++) {
-		gnd[i] = payload[3+4*i] | payload[4+4*i] << 8;
-		v_bg[i] = payload[5+4*i] | payload[6+4*i] << 8;
-	}
+	for (i = 0; i != DIAG_SAMPLES; i++)
+		v_bg[i] = payload[3+2*i] | payload[4+2*i] << 8;
 }
 
 
 static void diag_1(struct atrf_dsc *dsc, uint16_t pattern)
 {
-	uint16_t gnd[DIAG_SAMPLES], v_bg[DIAG_SAMPLES];
+	uint16_t v_bg[DIAG_SAMPLES];
 	int i;
 
-	send_diag(dsc, pattern, gnd, v_bg);
+	send_diag(dsc, pattern, v_bg);
 	printf("%d", pattern);
 	for (i = 0; i != DIAG_SAMPLES; i++)
-		printf(" %f %f", 1.1*1024/gnd[i], 1.1*1024/v_bg[i]);
+		printf(" %f", 1.1*1024/v_bg[i]);
 	printf("\n");
 	fflush(stdout);
 }