--- /dev/null
+/* Steelmate TPMS FSK protocol
+ *
+ * Copyright © 2016 Benjamin Larsson
+ * Copyright © 2016 John Jore
+ *
+ * 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.
+ *
+ * Packet payload: 9 bytes.
+ * Bytes 2 to 9 are inverted Manchester with swaped MSB/LSB:
+ *
+ * 0 1 2 3 4 5 6 7 8
+ * [00] {72} 00 00 7f 3c f0 d7 ad 8e fa
+ * After translating 00 00 01 c3 f0 14 4a 8e a0
+ * SS SS AA II II PP TT BB CC
+ * S = sync, (0x00)
+ * A = preamble, (0x01)
+ * I = id, 0xc3f0
+ * P = Pressure as double the PSI, 0x14 = 10 PSI
+ * T = Temperature in Fahrenheit, 0x4a = 74 'F
+ * B = Battery as half the millivolt, 0x8e = 2.84 V
+ * C = Checksum, adding bytes 2 to 7 modulo 256 = byte 8,(0x01+0xc3+0xf0+0x14+0x4a+0x8e) modulus 256 = 0xa0
+ */
+
+
+#include "rtl_433.h"
+#include "pulse_demod.h"
+#include "util.h"
+
+static int steelmate_callback(bitbuffer_t *bitbuffer) {
+ //if (debug_output >= 1) {
+ // fprintf(stdout, "Steelmate TPMS decoder\n");
+ // bitbuffer_print(bitbuffer);
+ // fprintf(stdout, "\n");
+ //}
+
+ char time_str[LOCAL_TIME_BUFLEN];
+ local_time_str(0, time_str);
+ bitrow_t *bb = bitbuffer->bb;
+
+ //Loop through each row of data
+ for (int i = 0; i < bitbuffer->num_rows; i++)
+ {
+ //Payload is inverted Manchester encoded, and reversed MSB/LSB order
+ uint8_t preAmble, ID1, ID2, p1, tempFahrenheit, tmpbattery_mV, payload_checksum, calculated_checksum;
+ uint16_t sensorID, battery_mV;
+ float pressurePSI;
+ char sensorIDhex[7];
+ data_t *data;
+
+ //Length must be 72 bits to be considered a valid packet
+ if (bitbuffer->bits_per_row[i] != 72)
+ continue;
+
+ //Valid preamble? (Note, the data is still wrong order at this point. Correct pre-amble: 0x00 0x00 0x01)
+ if (bb[i][0] != 0x00 || bb[i][1] != 0x00 || bb[i][2] != 0x7f)
+ continue;
+
+ //Preamble
+ preAmble = ~reverse8(bb[i][2]);
+
+ //Sensor ID
+ ID1 = ~reverse8(bb[i][3]);
+ ID2 = ~reverse8(bb[i][4]);
+
+ //Pressure is stored as twice the PSI
+ p1 = ~reverse8(bb[i][5]);
+
+ //Temperature is stored in Fahrenheit. Note that the datasheet claims operational to -40'C, but can only express values from -17.8'C
+ tempFahrenheit = ~reverse8(bb[i][6]);
+
+ //Battery voltage is stored as half the mV
+ tmpbattery_mV = ~reverse8(bb[i][7]);
+
+ //Checksum is a sum of all the other values
+ payload_checksum = ~reverse8(bb[i][8]);
+ calculated_checksum = preAmble + ID1 + ID2 + p1 + tempFahrenheit + tmpbattery_mV;
+ if (payload_checksum != calculated_checksum)
+ continue;
+
+ sensorID = (ID1 << 8) + ID2;
+ sprintf(sensorIDhex, "0x%04x", sensorID);
+ pressurePSI = (float)p1 / 2;
+ battery_mV = tmpbattery_mV * 2;
+
+ data = data_make("time", "", DATA_STRING, time_str,
+ "type", "", DATA_STRING, "TPMS",
+ "make", "", DATA_STRING, "Steelmate",
+ "id", "", DATA_STRING, sensorIDhex,
+ "pressure_PSI", "", DATA_DOUBLE, pressurePSI,
+ "temperature_F", "", DATA_DOUBLE, (float)tempFahrenheit,
+ "battery_mV", "", DATA_INT, battery_mV,
+ "checksum", "", DATA_STRING, "OK",
+ NULL);
+ data_acquired_handler(data);
+
+ return 1;
+ }
+
+ //Was not a Steelmate TPMS after all
+ return 0;
+}
+
+static char *output_fields[] = {
+ "time",
+ "type",
+ "make",
+ "id",
+ "pressure_PSI",
+ "temperature_F",
+ "battery_mV",
+ "checksum",
+ NULL
+};
+
+r_device steelmate = {
+ .name = "Steelmate TPMS",
+ .modulation = FSK_PULSE_MANCHESTER_ZEROBIT,
+ .short_limit = 12*4,
+ .long_limit = 0,
+ .reset_limit = 27*4,
+ .json_callback = &steelmate_callback,
+ .disabled = 0,
+ .fields = output_fields,
+};
projects / rtl-433.git / blobdiff