3 files changed, 8 insertions, 1 deletions
diff --git a/bus.c b/bus.c
index 0683113..43de205 100644
--- a/bus.c
+++ b/bus.c
@@ -325,7 +325,8 @@ static unsigned gpio_pins[] = {	GPIO0_X + 22,	// i.e., GPIO0_22
                                 GPIO0_X + 26,
                                 GPIO1_X + 15,	// i.e., GPIO1_15
                                 GPIO1_X + 14,
-                                GPIO0_X + 27
+                                GPIO0_X + 27,
+				GPIO1_X + 12
                               };
 
 
diff --git a/bus.h b/bus.h
index f13f203..c72aacb 100644
--- a/bus.h
+++ b/bus.h
@@ -18,6 +18,7 @@
 #define O_GATE 3                /* gates output */
 #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 */
 
 // A5, A6 used to select chips
 #define Octal_DACportCS_low	0x00
diff --git a/instr-daemon.c b/instr-daemon.c
index d749721..c03236b 100644
--- a/instr-daemon.c
+++ b/instr-daemon.c
@@ -311,6 +311,11 @@ int main(int argc, char **argv)
 
 static gboolean periodic_poll (void)
 {
+	if (bus_getpin (POWER_FAIL)) {
+		printf ("power fail detected\n");
+	} else {
+		printf ("power OK\n");
+	}
 
 	Menu_Check_Buttons ();