X-Git-Url: https://git.rvb.name/rtl-433.git/blobdiff_plain/ca13278b24eb61443559bcb61e64627fba3d8823..6d15c6f967221af825cf84e3ed12b96c763b127b:/src/devices/oil_watchman.c

diff --git a/src/devices/oil_watchman.c b/src/devices/oil_watchman.c
new file mode 100644
index 0000000..591e99b
--- /dev/null
+++ b/src/devices/oil_watchman.c
@@ -0,0 +1,121 @@
+/* Oil tank monitor using Si4320 framed FSK protocol
+ *
+ * Tested devices:
+ * Sensor Systems Watchman Sonic
+ *
+ * Copyright © 2015 David Woodhouse
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * 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.
+ */
+#include "rtl_433.h"
+#include "pulse_demod.h"
+#include "util.h"
+
+
+// Start of frame preamble is 111000xx
+static const unsigned char preamble_pattern = 0xe0;
+
+// End of frame is 00xxxxxx or 11xxxxxx depending on final data bit
+static const unsigned char postamble_pattern[2] = { 0x00, 0xc0 };
+
+static int oil_watchman_callback(bitbuffer_t *bitbuffer) {
+	uint8_t *b;
+	uint32_t unit_id;
+	uint16_t depth = 0;
+	uint16_t binding_countdown = 0;
+	uint8_t flags;
+	uint8_t maybetemp;
+	double temperature;
+	char time_str[LOCAL_TIME_BUFLEN];
+	data_t *data;
+	unsigned bitpos = 0;
+	bitbuffer_t databits = {0};
+	int events = 0;
+
+	local_time_str(0, time_str);
+
+	// Find a preamble with enough bits after it that it could be a complete packet
+	while ((bitpos = bitbuffer_search(bitbuffer, 0, bitpos, &preamble_pattern, 6)) + 136 <=
+	       bitbuffer->bits_per_row[0]) {
+
+		// Skip the matched preamble bits to point to the data
+		bitpos += 6;
+
+		bitpos = bitbuffer_manchester_decode(bitbuffer, 0, bitpos, &databits, 64);
+		if (databits.bits_per_row[0] != 64)
+			continue;
+
+		b = databits.bb[0];
+
+		// Check for postamble, depending on last data bit
+		if (bitbuffer_search(bitbuffer, 0, bitpos, &postamble_pattern[b[7] & 1], 2) != bitpos)
+			continue;
+
+		if (b[7] != crc8le(b, 7, 0x31, 0))
+			continue;
+
+		// The unit ID changes when you rebind by holding a magnet to the
+		// sensor for long enough; it seems to be time-based.
+		unit_id = (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3];
+
+		// 0x01: Rebinding (magnet held to sensor)
+		// 0x08: Leak/theft alarm
+		// top three bits seem also to vary with temperature (independently of maybetemp)
+		flags = b[4];
+
+		// Not entirely sure what this is but it might be inversely
+		// proportional to temperature.
+		maybetemp = b[5] >> 2;
+		temperature = (double)(145.0 - 5.0 * maybetemp) / 3.0;
+		if (flags & 1)
+			// When binding, the countdown counts up from 0x51 to 0x5a
+			// (as long as you hold the magnet to it for long enough)
+			// before the device ID changes. The receiver unit needs
+			// to receive this *strongly* in order to change its
+			// allegiance.
+			binding_countdown = b[6];
+		else
+			// A depth reading of zero indicates no reading. Even with
+			// the sensor flat down on a table, it still reads about 13.
+			depth = ((b[5] & 3) << 8) | b[6];
+
+		data = data_make("time", "", DATA_STRING, time_str,
+				 "model", "", DATA_STRING, "Oil Watchman",
+				 "id", "", DATA_FORMAT, "%06x", DATA_INT, unit_id,
+				 "flags", "", DATA_FORMAT, "%02x", DATA_INT, flags,
+				 "maybetemp", "", DATA_INT, maybetemp,
+				 "temperature_C", "", DATA_DOUBLE, temperature,
+				 "binding_countdown", "", DATA_INT, binding_countdown,
+				 "depth", "", DATA_INT, depth,
+				 NULL);
+		data_acquired_handler(data);
+		events++;
+	}
+	return events;
+};
+
+static char *output_fields[] = {
+	"time",
+	"model",
+	"id",
+	"flags",
+	"maybetemp",
+	"temperature_C",
+	"binding_countdown",
+	"depth",
+	NULL
+};
+
+r_device oil_watchman = {
+	.name			= "Watchman Sonic / Apollo Ultrasonic / Beckett Rocket oil tank monitor",
+	.modulation		= FSK_PULSE_PCM,
+	.short_limit	= 1000,
+	.long_limit     = 1000, // NRZ
+	.reset_limit    = 4000,
+	.json_callback	= &oil_watchman_callback,
+	.disabled		= 0,
+	.fields			= output_fields,
+};