Add protocol 278 'omni.c' device driver for microcontroller multisensor protocol

README.md

@@ -363,6 +363,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [275]  GM-Aftermarket TPMS
     [276]  RainPoint HCS012ARF Rain Gauge sensor
     [277]  Apator Metra E-RM 30
+    [278]  Omni Multisensor
 
 * Disabled by default, use -R n or a conf file to enable
 
@@ -372,7 +373,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
   [-d <RTL-SDR USB device index>] (default: 0)
   [-d :<RTL-SDR USB device serial (can be set with rtl_eeprom -s)>]
 	To set gain for RTL-SDR use -g <gain> to set an overall gain in dB.
-	SoapySDR device driver is available.
+	SoapySDR device driver is not available.
   [-d ""] Open default SoapySDR device
   [-d driver=rtlsdr] Open e.g. specific SoapySDR device
 	To set gain for SoapySDR use -g ELEM=val,ELEM=val,... e.g. -g LNA=20,TIA=8,PGA=2 (for LimeSDR).

conf/rtl_433.example.conf

@@ -516,6 +516,7 @@ convert si
   protocol 275 # GM-Aftermarket TPMS
   protocol 276 # RainPoint HCS012ARF Rain Gauge sensor
   protocol 277 # Apator Metra E-RM 30
+  protocol 278 # Omni Multisensor
 
 ## Flex devices (command line option "-X")
 

include/rtl_433_devices.h

@@ -285,7 +285,7 @@
     DECL(tpms_gm) \
     DECL(rainpoint_hcs012arf) \
     DECL(apator_metra_erm30) \
-
+    DECL(omni) \
     /* Add new decoders here. */
 
 #define DECL(name) extern r_device name;

man/man1/rtl_433.1

@@ -168,7 +168,7 @@ RTL\-SDR device driver is available.
 To set gain for RTL\-SDR use \-g <gain> to set an overall gain in dB.
 .RE
 .RS
-SoapySDR device driver is available.
+SoapySDR device driver is not available.
 .RE
 .TP
 [ \fB\-d\fI ""\fP ]

src/CMakeLists.txt

@@ -192,6 +192,7 @@ add_library(r_433 STATIC
     devices/oil_standard.c
     devices/oil_watchman.c
     devices/oil_watchman_advanced.c
+    devices/omni.c
     devices/opus_xt300.c
     devices/oregon_scientific.c
     devices/oregon_scientific_sl109h.c

src/devices/omni.c

@@ -0,0 +1,243 @@
+/** @file
+    Omni Multisensor.
+
+    Copyright (C) 2025 H. David Todd <[email protected]>
+
+    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.
+*/
+/**
+The 'sensor' is actually a programmed microcontroller, such as
+Raspberry Pi Pico 2 or similar, with multiple possible data-sensor
+attachments.  A message 'format' field indicates the format of the data
+packet being sent.  The protocol, and this decoder, support up to
+16 different message formats:
+-  Single transmission protocol
+-  Flexible 64-bit data payload field structure
+-  Two initial formats, extensible to a total of 16 possible formats.
+
+NOTE: the rtl_433 decoder, omni.c, uses the "fmt" or "Format" field
+here, as transmitted by omni.c, to decode the incoming message.
+But, through omni.c, rtl_433 reports the packet format-field value
+as "channel" in its published reporting (JSON, for example),
+in keeping with the standard nomenclature and order of field-name
+precedence used within rtl_433 for data fields.
+
+The omni protocol is OOK modulated PWM with fixed period of 600μs
+for data bits, preambled by four long startbit pulses of fixed period equal
+to 1200μs. It is similar to the Lacrosse TX141TH-BV2.
+
+A single data packet looks as follows:
+1) preamble - 600μs high followed by 600μs low, repeated 4 times:
+
+     ----      ----      ----      ----
+    |    |    |    |    |    |    |    |
+          ----      ----      ----      ----
+
+2) a train of 80 data pulses with fixed 600μs period follows immediately:
+
+     ---    --     --     ---    ---    --     ---
+    |   |  |  |   |  |   |   |  |   |  |  |   |   |
+         --    ---    ---     --     --    ---     -- ....
+
+A logical 0 is 400μs of high followed by 200μs of low.
+A logical 1 is 200μs of high followed by 400μs of low.
+
+Thus, in the example pictured above the bits are 0 1 1 0 0 1 0 ...
+
+The omni microcontroller sends 4 of identical packets of
+4-pulse preamble followed by 80 data bits in a single burst, for a
+total of 336 bits requiring ~212μs.
+
+The last packet in a burst is followed by a postamble low
+of at least 1250μs.
+
+These 4-packet bursts repeat every 30 seconds.
+
+The message in each packet is 10 bytes / 20 nibbles:
+
+    [fmt] [id] 16*[data] [crc8] [crc8]
+
+- fmt is a 4-bit message data format identifier
+- id is a 4-bit device identifier
+- data are 16 nibbles = 8 bytes of data payload fields,
+      interpreted according to 'fmt'
+- crc8 is 2 nibbles = 1 byte of CRC8 checksum of the first 9 bytes:
+      polynomial 0x97, init 0xaa
+
+A format=0 message simply transmits the core temperature and input power
+voltage of the microcontroller and is the format used if no data
+sensor is present.  For format=0 messages, the message
+nibbles are to be read as:
+
+     fi tt t0 00 00 00 00 00 vv cc
+
+     f: format of datagram, 0-15
+     i: id of device, 0-15
+     t: Pico 2 core temperature: °C *10, 12-bit, 2's complement integer
+     0: bytes should be 0 (but aren't required to be)
+     v: (VCC-3.00)*100, as 8-bit integer, in volts: 3V00..5V55 volts
+     c: CRC8 checksum of bytes 1..9, initial remainder 0xaa,
+        divisor polynomial 0x97, no reflections or inversions
+
+A format=1 message format is provided as a more complete example.
+It uses the Bosch BME688 environmental sensor as a data source.
+It is an indoor-outdoor temperature/humidity/pressure sensor, and the
+message packet has the following fields:
+    indoor temp, outdoor temp, indoor humidity, outdoor humidity,
+    barometric pressure, sensor power VCC.
+The data fields are binary values, 2's complement for temperatures.
+For format=1 messages, the message nibbles are to be read as:
+
+     fi 11 12 22 hh gg pp pp vv cc
+
+     f: format of datagram, 0-15
+     i: id of device, 0-15
+     1: sensor 1 temp reading (e.g, indoor),  °C *10, 12-bit, 2's complement integer
+     2: sensor 2 temp reading (e.g, outdoor), °C *10, 12-bit, 2's complement integer
+     h: sensor 1 humidity reading (e.g., indoor),  %RH as 8-bit integer
+     g: sensor 2 humidity reading (e.g., outdoor), %RH as 8-bit integer
+     p: barometric pressure * 10, in hPa, as 16-bit integer, 0..6553.5 hPa
+     v: (VCC-3.00)*100, as 8-bit integer, in volts: 3V00..5V55 volts
+     c: CRC8 checksum of bytes 1..9, initial remainder 0xaa,
+            divisor polynomial 0x97, no reflections or inversions
+*/
+
+#include "decoder.h"
+
+#define initCRC 0xaa
+#define OMNI_MSGFMT_00 0x00
+#define OMNI_MSGFMT_01 0x01
+
+static int omni_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    // Find a row that's a candidate for decoding
+    int r = bitbuffer_find_repeated_row(bitbuffer, 2, 80);
+
+    if (r < 0 || bitbuffer->bits_per_row[r] > 82) {
+        decoder_log(decoder, 1, __func__, "omni: Invalid message");
+        return DECODE_ABORT_LENGTH;
+    };
+
+    // OK, that's our message buffer for decoding
+    uint8_t *b = bitbuffer->bb[r];
+
+    // Validate the packet against the CRC8 checksum
+    if (crc8(b, 9, 0x97, initCRC) != b[9]) {
+        decoder_log(decoder, 1, __func__, "omni: CRC8 checksum error");
+        return DECODE_FAIL_MIC;
+    }
+
+    // OK looks like we have a valid packet.  What format?
+    int message_fmt = b[0] >> 4;
+    int id          = b[0] & 0x0F;
+    char hexstring[50];
+    char *ptr;
+    data_t *data;
+
+    // Decode that format, if we know it
+    switch (message_fmt) {
+
+    // Default to fmt=00 so unformatted message data are reported in hex
+    case OMNI_MSGFMT_00:
+        ptr = &hexstring[0];
+        // print just the 8 data bytes as payload data
+        for (int ij = 1; ij < 9; ij++)
+            ptr += sprintf(ptr, "%02x", b[ij]);
+        double itemp_c = (double)(((int16_t)( b[1]<<8  | b[2] )) >> 4) * 0.10;
+        double volts   = ((double)(b[8])) * 0.01 + 3.00;
+        // Make the data descriptor
+        /* clang-format off */
+        data = data_make(
+            "model",           "",                                               DATA_STRING, "Omni-Multisensor",
+            "id",              "Id",                                             DATA_INT,     id,
+            "channel",         "Format",                                         DATA_INT,     message_fmt,
+            "temperature_C"  , "Core Temperature",   DATA_FORMAT, "%.2f ˚C",     DATA_DOUBLE,  itemp_c,
+            "voltage_V",       "VCC voltage",        DATA_FORMAT, "%.2f V",      DATA_DOUBLE,  volts,
+            "payload",         "Payload",                                        DATA_STRING,  hexstring,
+            "mic",             "Integrity",                                      DATA_STRING,  "CRC",
+            NULL);
+        /* clang-format on */
+        break;
+
+    case OMNI_MSGFMT_01:
+        itemp_c = (double)(((int16_t)( b[1]<<8  | b[2] )) >> 4) * 0.10;
+        double otemp_c = (double) (((int16_t)(b[2]<<12 | b[3]<<4 )) >> 4) * 0.10;
+        double ihum    = (double)b[4];
+        double light   = (double)b[5];
+        double press   = (double)(((uint16_t)(b[6] << 8)) | b[7]) * 0.10;
+        volts          = ((double)(b[8])) * 0.01 + 3.00;
+        // Make the data descriptor
+        /* clang-format off */
+        data = data_make(
+            "model",           "",                                               DATA_STRING, "Omni-Multisensor",
+            "id",              "Id",                                             DATA_INT,     id,
+            "channel",         "Format",                                         DATA_INT,     message_fmt,
+            "temperature_C"  , "Indoor Temperature", DATA_FORMAT, "%.2f ˚C",     DATA_DOUBLE,  itemp_c,
+            "temperature_2_C", "Outdoor Temperature",DATA_FORMAT, "%.2f ˚C",     DATA_DOUBLE,  otemp_c,
+            "humidity",        "Indoor Humidity",    DATA_FORMAT, "%.0f %%",     DATA_DOUBLE,  ihum,
+            "light_pct",       "Light",              DATA_FORMAT, "%.0f %%",      DATA_DOUBLE,  light,
+            "pressure_hPa",    "BarometricPressure", DATA_FORMAT, "%.1f hPa",    DATA_DOUBLE,  press,
+            "voltage_V",       "VCC voltage",        DATA_FORMAT, "%.2f V",      DATA_DOUBLE,  volts,
+            "mic",             "Integrity",                                      DATA_STRING,  "CRC",
+            NULL);
+        /* clang-format on */
+        break;
+
+    default:
+        // Print the whole 10 bytes in hex, with id and fmt explicit
+        ptr = &hexstring[0];
+        // print just the 8 data bytes as payload data
+        for (int ij = 1; ij < 9; ij++)
+            ptr += sprintf(ptr, "%02x", b[ij]);
+        // Make the data descriptor
+        data = data_make(
+            "model",   "",          DATA_STRING, "Omni-Multisensor",
+            "id",      "Id",        DATA_INT,     id,
+            "channel", "Format",    DATA_INT,     message_fmt,
+            "payload", "Payload",   DATA_STRING,  hexstring,
+            "mic",     "Integrity", DATA_STRING,  "CRC",
+            NULL);
+        break;
+
+        /* New decoders follow here */
+        break;
+
+    };
+
+    // And output the field values
+    decoder_output_data(decoder, data);
+    return 1; // if we got here, one valid message was returned
+}
+
+// List the output fields for various message types
+static char const *const output_fields[] = {
+        "model",
+        "fmt",
+        "id",
+        "temperature_C",
+        "temperature_2_C",
+        "humidity",
+        "pressure_hPa",
+        "light_pct",
+        "voltage_V",
+        "payload",
+        "mic",
+        NULL,
+};
+
+/* clang-format off */
+r_device const omni = {
+        .name        = "Omni Multisensor",
+        .modulation  = OOK_PULSE_PWM,
+        .short_width = 200,  // short pulse is ~200 us
+        .long_width  = 400,  // long pulse is ~400 us
+        .sync_width  = 600,  // sync pulse is ~600 us
+        .gap_limit   = 500,  // long gap (with short pulse) is ~400 us, sync gap is ~600 us
+        .reset_limit = 1250, // maximum gap is 1250 us (long gap + longer sync gap on last repeat)
+        .decode_fn   = &omni_decode,
+        .fields      = output_fields,
+};
+/* clang-format on */