Add support for Gasmate-BA1008 (#2359)

Author: zuckschwerdt

README.md

@@ -318,6 +318,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [233]* CED7000 Shot Timer
     [234]  Watchman Sonic Advanced / Plus
     [235]  Oil Ultrasonic SMART FSK
+    [236]  Gasmate BA1008 meat thermometer
 
 * Disabled by default, use -R n or a conf file to enable
 

conf/rtl_433.example.conf

@@ -457,6 +457,7 @@ stop_after_successful_events false
 # protocol 233 # CED7000 Shot Timer
   protocol 234 # Watchman Sonic Advanced / Plus
   protocol 235 # Oil Ultrasonic SMART FSK
+  protocol 236 # Gasmate BA1008 meat thermometer
 
 ## Flex devices (command line option "-X")
 

include/rtl_433_devices.h

@@ -243,6 +243,7 @@
     DECL(ced7000) \
     DECL(oil_watchman_advanced) \
     DECL(oil_smart) \
+    DECL(gasmate_ba1008) \
 
     /* Add new decoders here. */
 

src/CMakeLists.txt

@@ -114,6 +114,7 @@ add_library(r_433 STATIC
     devices/fs20.c
     devices/ft004b.c
     devices/funkbus.c
+    devices/gasmate_ba1008.c
     devices/ge_coloreffects.c
     devices/generic_motion.c
     devices/generic_remote.c

src/devices/gasmate_ba1008.c

@@ -0,0 +1,111 @@
+/** @file
+    Gasmate BA1008 meat thermometer.
+
+    Copyright (C) 2023 Christian W. Zuckschwerdt <[email protected]>
+    based on protocol analysis by Lucy Winters
+
+    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 "decoder.h"
+
+/**
+Gasmate BA1008 meat thermometer.
+
+Notably this protocol does not feature ID or CHANNEL information.
+
+S.a. #2324
+
+Data Layout:
+
+    PF TT ?? ?A
+
+- P: (4 bit) preamble/model/type? fixed 0xf
+- F: (4 bit) Unknown bit; Sign bit; 2-bit temperature 100ths (BCD)
+- T: (8 bit) temperature 10ths and 1ths (BCD)
+- ?: (12 bit) unknown value
+- A: (4 bit) checksum, nibble-wide add with carry
+
+Raw data:
+
+    F4040BFB [-04C]
+    F4060BF9 [-06C]
+    F4100BEF [-10C]
+    f0030ffc [+03C]
+    F0230FDC [+23C]
+    F0310FCE [+31C]
+
+Format string:
+
+    PREAMBLE?h ?b SIGN:b TEMP:2hhhC ?hhh CHK:h
+
+*/
+
+static int gasmate_ba1008_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    if (bitbuffer->num_rows != 1) {
+        decoder_log(decoder, 2, __func__, "Row check fail");
+        return DECODE_ABORT_LENGTH;
+    }
+
+    int row = 0;
+    uint8_t *b = bitbuffer->bb[row];
+    // we expect 32 bits
+    if (bitbuffer->bits_per_row[row] != 32) {
+        decoder_log(decoder, 2, __func__, "Length check fail");
+        return DECODE_ABORT_LENGTH;
+    }
+
+    // preamble/model/type and first flag bit check
+    if ((b[0] & 0xf8) != 0xf0) {
+        decoder_log(decoder, 2, __func__, "Model check fail");
+        return DECODE_ABORT_EARLY;
+    }
+
+    // check checksum
+    if ((add_nibbles(b, 4) & 0x0f) != 0x0c) {
+        decoder_log(decoder, 2, __func__, "Checksum fail");
+        return DECODE_FAIL_MIC;
+    }
+
+    int sign     = (b[0] & 0x04) >> 2;
+    int huns     = (b[0] & 0x03);
+    int tens     = (b[1] & 0xf0) >> 4;
+    int ones     = (b[1] & 0x0f);
+    int temp_raw = huns * 100 + tens * 10 + ones;
+    int temp_c   = sign ? -temp_raw : temp_raw;
+    int unknown1 = (b[2] << 4) | (b[3] >> 4);
+
+    /* clang-format off */
+    data_t *data = data_make(
+            "model",            "",                 DATA_STRING, "Gasmate-BA1008",
+            "temperature_C",    "Temperature_C",    DATA_FORMAT, "%d C", DATA_INT, temp_c,
+            "unknown_1",        "Unknown Value",    DATA_FORMAT, "%03x", DATA_INT,    unknown1,
+            "mic",              "Integrity",        DATA_STRING, "CHECKSUM",
+            NULL);
+    /* clang-format on */
+
+    decoder_output_data(decoder, data);
+    return 1;
+}
+
+static char *output_fields[] = {
+        "model",
+        "temperature_C",
+        "unknown_1",
+        "mic",
+        NULL,
+};
+
+r_device const gasmate_ba1008 = {
+        .name        = "Gasmate BA1008 meat thermometer",
+        .modulation  = OOK_PULSE_PPM,
+        .short_width = 536,
+        .long_width  = 1668,
+        .reset_limit = 2000,
+        .decode_fn   = &gasmate_ba1008_decode,
+        .fields      = output_fields,
+};