GPIO Signal Timing Tests

1 files changed, 35 insertions, 7 deletions

diff --git a/usr/main.c b/usr/main.c
index b6e540d..1bc5c75 100644
--- a/usr/main.c
+++ b/usr/main.c
@@ -1,3 +1,4 @@
+#include <cpu.h>
 #include <globals.h>
 #include <graphics/lfb.h>
 #include <symbols.h>
@@ -5,6 +6,7 @@
 #include <usr/string.h>
 #include <usr/timed.h>
 #include <usr/uart.h>
+#include <usr/math.h>
 
 static struct SysTimerInfo stime_0 = {
 	.tick_rate = 5000000,
@@ -42,11 +44,37 @@ static struct GPIOInfo gpinfo = {
 void gptest(void)
 {
 	static unsigned long count = 0;
-	unsigned long gplev0 = *GPLEV0;
-	static char str[14];
-	draw_hex32(0, 30, gplev0);
-	char* start = ulong_to_string(count++, str);
-	draw_string(0, 31, start);
+	static unsigned long long ts[4096*2+20];
+	sys0_64(SYS_TIME, &ts[count++]);
+	if (count == (4096*2+18)) {
+		unsubscribe_irq(GPIO_BANK_1_IRQ);
+		static char str[14];
+		char* start;
+		unsigned long mean=0, stdev=0, max=0;
+		for (unsigned long i = 0; i < 4096; i++) {
+			unsigned long elapsed = ts[2*(i+2)+1]-ts[2*(i+2)];
+			mean += elapsed;
+			if (elapsed > max)
+				max = elapsed;
+		}
+		mean /= 4096;
+		for (unsigned long i = 0; i < 4096; i++) {
+			unsigned long elapsed = ts[2*(i+2)+1]-ts[2*(i+2)];
+			unsigned long term = (elapsed-mean)*(elapsed-mean)/4096;
+			stdev += term;
+		}
+		stdev = sqrt_rnd(stdev);
+		start = ulong_to_string(mean, str);
+		draw_string(0, 10, start);
+		start = ulong_to_string(stdev, str);
+		draw_string(0, 11, start);
+		start = ulong_to_string(max, str);
+		draw_string(0, 12, start);
+	}
+	//unsigned long gplev0 = *GPLEV0;
+	//draw_hex32(0, 30, gplev0);
+	//start = ulong_to_string(count++, str);
+	//draw_string(0, 31, start);
 }
 
 void test_super(void);
@@ -58,8 +86,8 @@ void main(void)
 	//subscribe_irq(SYS_TIMER_1_IRQ, loopt, &stime_1);
 	//subscribe_irq(SYS_TIMER_2_IRQ, loopt, &stime_2);
 	//subscribe_irq(SYS_TIMER_3_IRQ, loopt, &stime_3);
-	//subscribe_irq(GPIO_BANK_1_IRQ, gptest, &gpinfo);
+	subscribe_irq(GPIO_BANK_1_IRQ, gptest, &gpinfo);
 	//add_thread(loop, 0, 8);
 	//add_thread(consumer, 0, 3);
-	add_thread(test_super, 0, 4);
+	//add_thread(test_super, 0, 4);
 }