From d0a309bb6516a4ebdb61129deb76d359139dd1e1 Mon Sep 17 00:00:00 2001
From: "Christian W. Zuckschwerdt" <christian@zuckschwerdt.org>
Date: Mon, 22 Jan 2018 11:55:56 +0100
Subject: [PATCH] change fordremore to proper DMC, the output is vastly
 different

---
 src/devices/fordremote.c | 89 +++++++++++++++++++++-------------------
 1 file changed, 47 insertions(+), 42 deletions(-)

diff --git a/src/devices/fordremote.c b/src/devices/fordremote.c
index c2a987a7..bf0a1d46 100644
--- a/src/devices/fordremote.c
+++ b/src/devices/fordremote.c
@@ -7,56 +7,60 @@
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- *           dd dd dd 
- * [00] {60} 74 28 c1 06 a4 1a 05 20
- * [00] {60} 74 28 c1 06 a4 1a 05 20
- * [00] {60} 74 28 c1 06 a4 1a 05 20
- * [00] {60} 74 28 c1 06 a4 1a 05 20
+ *
+ * Note: this used to have a broken PWM decoding, but is now proper DMC.
+ * The output changed and the fields are very likely not as intended. 
+ *
+ * [00] {1} 80 : 1
+ * [01] {9} 00 80 : 00000000 1
+ * [02] {1} 80 : 1
+ * [03] {78} 03 e0 01 e4 e0 90 52 97 39 60
  */
 
 #include "rtl_433.h"
 #include "data.h"
 #include "util.h"
-#define FORD_BITLEN  40
-#define FORD_BYTELEN 5
-#define FORD_PACKETCOUNT 4
 
 static int fordremote_callback(bitbuffer_t *bitbuffer) {
-	bitrow_t *bb = bitbuffer->bb;
-        uint8_t *bytes = bitbuffer->bb[0];
 	data_t *data;
 	char time_str[LOCAL_TIME_BUFLEN];
-    	local_time_str(0, time_str);
-	int i;
-    	uint32_t device_id =0;
-	unsigned bits = bitbuffer->bits_per_row[0];
+	uint8_t *bytes;
+	int found = 0, i;
+	int device_id, code;
+
+	// expect {1} {9} {1} preamble
+	for (int i = 3; i < bitbuffer->num_rows; i++) {
+		if (bitbuffer->bits_per_row[i] < 78) {
+			continue; // not a data row
+		}
 
-	for (int i = 0; i < bitbuffer->num_rows; i++) {
 		// Validate preamble
-		if ((bitbuffer->bits_per_row[i] == 6) && (bytes[00]==120)) {
-			if (debug_output) {
-                		bitbuffer_print(bitbuffer);
-                	}
-		} else if ((bitbuffer->bits_per_row[i] > 55) && ((bb[i][0] >> 4)==7)) {
-			if (debug_output) {
-				bitbuffer_print(bitbuffer);
-			}
-			device_id = ((bb[i][0]<<16)| (bb[i][1]<<8)|(bb[i][2]));
-			uint16_t code = (bb[i][7]);
-			/* Get time now */
-			local_time_str(0, time_str);
-			data = data_make(
-        			"time",		"time",		DATA_STRING, time_str,
+		if (bitbuffer->bits_per_row[i - 3] != 1 || bitbuffer->bits_per_row[i - 1] != 1
+				|| bitbuffer->bits_per_row[i - 2] != 9 || bitbuffer->bb[i - 2][0] != 0) {
+			continue; // no valid preamble
+		}
+
+		if (debug_output) {
+			bitbuffer_print(bitbuffer);
+		}
+
+		bytes = bitbuffer->bb[i];
+		device_id = (bytes[0]<<16) | (bytes[1]<<8) | bytes[2];
+		code = bytes[7];
+
+		/* Get time now */
+		local_time_str(0, time_str);
+		data = data_make(
+	   			"time",		"time",		DATA_STRING, time_str,
 				"model",	"model",	DATA_STRING, "Ford Car Remote",
 				"id",		"device-id",	DATA_INT, device_id,
 				"code", 	"data",		DATA_INT, code,
 				NULL);
-			data_acquired_handler(data);
-			return 1;
-		}
-		return 0;
+		data_acquired_handler(data);
+
+		found++;
 	}
-	return 0;
+	return found;
 }
 
 static char *output_fields[] = {
@@ -68,13 +72,14 @@ static char *output_fields[] = {
 };
 
 r_device fordremote = {
-	.name		= "Ford Car Key",
-	.modulation	= OOK_PULSE_PWM_TERNARY,
-	.short_limit	= 312,
-	.long_limit	= 625,	// Not used
-	.reset_limit	= 1500,
+	.name			= "Ford Car Key",
+	.modulation		= OOK_PULSE_CLOCK_BITS,
+	.short_limit	= 250,  // half-bit width is 250 us
+	.long_limit		= 500,	// bit width is 500 us
+	.reset_limit	= 4000, // sync gap is 3500 us, preamble gap is 38400 us, packet gap is 52000 us
+	.tolerance		= 50,
 	.json_callback	= &fordremote_callback,
-	.disabled	= 0,
-	.demod_arg	= 2,
-        .fields		= output_fields
+	.disabled		= 0,
+	.demod_arg		= 0,
+	.fields			= output_fields
 };