add a dedicated pin to reset GPIB, becase SYS_RESETn is flaky

3 files changed, 10 insertions, 1 deletions

diff --git a/bus.c b/bus.c
index e733cdf..1c77e70 100644
--- a/bus.c
+++ b/bus.c
@@ -356,7 +356,8 @@ static unsigned gpio_pins[] = {	GPIO0_X + 22,	// i.e., GPIO0_22
                                 GPIO1_X + 15,	// i.e., GPIO1_15
                                 GPIO1_X + 14,
                                 GPIO0_X + 27,
-                                GPIO1_X + 12
+                                GPIO1_X + 12,
+				GPIO2_X + 1
                               };
 
 
diff --git a/bus.h b/bus.h
index 7f01cf3..f62e931 100644
--- a/bus.h
+++ b/bus.h
@@ -19,6 +19,7 @@
 #define OUTPUT_RELAY 4          /* output enable/disable relay */
 #define PW_ENABLE 5             /* TTL enable/disable output */
 #define POWER_FAIL 6		/* pulled low if +24V OK, pulled high if power fails */
+#define RST_GPIB 7		/* don't use SYS_RESETn for this purpose - unpredictable */
 
 // A5, A6 used to select chips
 #define Octal_DACportCS_low	0x00
diff --git a/gpib.c b/gpib.c
index 46b1e14..88986b4 100644
--- a/gpib.c
+++ b/gpib.c
@@ -413,6 +413,13 @@ static void TNT_Gen_Error(int code)
 /*----------------------------------------------------------------------------------------------------------*/
 void GPIB_initialize(void)
 {
+	// The RST_GPIB pin should already be low - defaults to low at
+	// power on.
+	bus_setpin(RST_GPIB, 0);
+	g_usleep(1);
+        bus_setpin(RST_GPIB, 1);
+	g_usleep(100);
+
 	INTERFACE_STATUS=0;		/* Initialize Globals to zero */
 	INTERFACE_ERROR=0;
 	DATA_COUNT=0;