From 1cddbdf08f1e0661db64644c902b7665985f59e1 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sun, 6 Feb 2022 20:37:15 +0100
Subject: [PATCH] test-display: IR test

---
 test-display/config.h |  4 ++
 test-display/main.c   | 94 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/test-display/config.h b/test-display/config.h
index 312c7be..fe39e28 100644
--- a/test-display/config.h
+++ b/test-display/config.h
@@ -12,3 +12,7 @@
 
 #define DEBUG_USART USART1
 #define DEBUG_LED_BLUEPILL
+
+// Testing of IR receiver
+
+#undef IR_TEST
diff --git a/test-display/main.c b/test-display/main.c
index 8fd5636..a00c20a 100644
--- a/test-display/main.c
+++ b/test-display/main.c
@@ -55,6 +55,9 @@ static void gpio_init(void)
 	// PB7 = SDA for display controller
 	// PB6 = SCL for display controller
 	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, GPIO6 | GPIO7);
+
+	// PB8 = SFH5110 output (5V tolerant)
+	gpio_set_mode(GPIOC, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO8);
 }
 
 static void usart_init(void)
@@ -118,7 +121,7 @@ static byte ctrl = 0x56;
 
 static void display_update(void)
 {
-	debug_puts("Display pdate\n");
+	debug_puts("Display update\n");
 	byte cmds[4];
 	cmds[0] = 0;
 	cmds[1] = ctrl;
@@ -390,14 +393,101 @@ static void usb_init(void)
 	usb_event_pending = 1;
 }
 
+/*** Testing of IR receiver ***/
+
+#ifdef IR_TEST
+
+static u16 get_bit(void)
+{
+#if 1
+	return !gpio_get(GPIOB, GPIO8);
+#else
+	int x = 0;
+	x += !gpio_get(GPIOB, GPIO8);
+	x += !gpio_get(GPIOB, GPIO8);
+	x += !gpio_get(GPIOB, GPIO8);
+	x += !gpio_get(GPIOB, GPIO8);
+	return x >= 2;
+#endif
+}
+
+#define MAX_SAMPLES 1024
+u32 samples[MAX_SAMPLES];
+
+static void ir_test_loop(void)
+{
+	debug_puts("\n\n### Infrared Remote Control receiver ###\n\n");
+
+	systick_set_reload(0xffffff);
+	systick_counter_enable();
+	systick_interrupt_disable();
+	systick_clear();
+
+	for (;;) {
+		gpio_set(GPIOC, GPIO13);
+
+		if (get_bit()) {
+			debug_puts("Waiting for silence\n");
+			while (get_bit())
+				;
+		}
+		debug_puts("Ready...");
+
+		u16 last = 0;
+		uint nsamp = 0;
+		u32 start;
+
+		do {
+			start = systick_get_value();
+			last = get_bit();
+		} while (!last);
+
+		gpio_clear(GPIOC, GPIO13);
+
+		for (;;) {
+			u32 now;
+			u16 curr;
+			uint len;
+			do {
+				now = systick_get_value();
+				len = (start - now) & 0xffffff;
+				if (len > 5000000) {
+					samples[nsamp++] = len;
+					goto timeout;
+				}
+				curr = get_bit();
+			} while (curr == last);
+			samples[nsamp++] = len;
+			if (nsamp >= MAX_SAMPLES)
+				break;
+			start = now;
+			last = curr;
+		}
+
+	timeout:
+		for (uint i=0; i<nsamp; i++) {
+			debug_putc(i ? ' ' : '\n');
+			debug_printf("%u", (unsigned int)((samples[i] + CPU_CLOCK_MHZ - 1) / CPU_CLOCK_MHZ));	// in μs
+		}
+		debug_putc('\n');
+	}
+}
+
+#endif
+
 /*** Main ***/
 
 int main(void)
 {
 	clock_init();
 	gpio_init();
-	tick_init();
 	usart_init();
+
+#ifdef IR_TEST
+	ir_test_loop();
+#endif
+
+	tick_init();
 	desig_get_unique_id_as_dfu(usb_serial_number);
 
 	debug_printf("Hello, world!\n");
-- 
2.39.2