Add support for RFM69 LowPowerLab Moteino

Author: icockett

README.md

@@ -405,6 +405,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [315]  Alps FWB1U545 Car Remote
     [316]  Continental KR5V2X Car Remote (-f 313.8M -s 1024k)
     [317]  Code Alarm FRDPC2002 Car Remote
+    [318]  RFM69 LowPowerLab Moteino board (-s 1000k)
 
 * Disabled by default, use -R n or a conf file to enable
 

conf/rtl_433.example.conf

@@ -556,6 +556,7 @@ convert si
   protocol 315 # Alps FWB1U545 Car Remote
   protocol 316 # Continental KR5V2X Car Remote (-f 313.8M -s 1024k)
   protocol 317 # Code Alarm FRDPC2002 Car Remote
+  protocol 318 # RFM69 LowPowerLab Moteino board (-s 1000k)
 
 ## Flex devices (command line option "-X")
 

include/rtl_433_devices.h

@@ -325,7 +325,7 @@
     DECL(alps_fwb1u545_car_remote) \
     DECL(continental_car_remote) \
     DECL(code_alarm_frdpc2000_car_remote) \
-
+    DECL(rfm69_lowpowerlab_moteino) \
     /* Add new decoders here. */
 
 #define DECL(name) extern r_device name;

src/CMakeLists.txt

@@ -232,6 +232,7 @@ add_library(r_433 STATIC
     devices/regency_fan.c
     devices/revolt_nc5462.c
     devices/revolt_zx7717.c
+    devices/rfm69_lowpowerlab_moteino.c
     devices/rftech.c
     devices/risco_agility.c
     devices/rojaflex.c

src/devices/rfm69_lowpowerlab_moteino.c

@@ -0,0 +1,130 @@
+/** @file
+    RFM69 decoder as used on LowPowerLabs Moteino boards
+
+    Copyright (C) 2025 Ian Cockett <cockettian@gmail.com>
+
+    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"
+
+/**
+
+Generic decoder for RFM69 radio modules as used on LowPowerLab.com Moteino boards.
+
+    rtl_433 -s 1000k
+
+Test data captured with sample sketch https://github.com/LowPowerLab/RFM69/blob/master/Examples/Node/Node.ino
+
+Encryption must be disabled in the sketch (comment out #define ENCRYPTKEY)
+Data captures from 433MHz RFM69HW_HCW board, but 868MHz models should be similar
+
+Protocol description:-
+
+-   Preamble    aaaaaa
+-   Sync word   2d64
+-   Header byte 1 - Length Byte
+-   Header byte 2 - Dest Address
+-   Header byte 3 - Src Address
+-   Header byte 4 - Control byte    (not sure what this does)
+-   n bytes variable length message.
+-   CRC16 checksum
+
+*/
+
+#define LENGTH_POS     5
+#define NODE_ID_POS    7
+#define DATA_START_POS 9
+
+#define HEADER_LENGTH  6
+#define MAX_LENGTH     65
+#define BUF_LENGTH     72
+
+static int rfm69_fsk_callback(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    data_t *data;
+
+    uint8_t search = 0x2d; // sync byte to scan for
+
+    uint8_t message[BUF_LENGTH]; // max size of header + payload + terminator
+    uint8_t payload[MAX_LENGTH]; // max size of payload + terminator
+
+    unsigned posn = bitbuffer_search(bitbuffer, 0, 0, &search, 8);
+
+    if ((posn < 24) || (posn > 28))
+        return 0; // Can't find bit position of sync word
+
+    bitbuffer_extract_bytes(bitbuffer, 0, posn - 24, (uint8_t *)&message, (MAX_LENGTH) * 8); // Extract out full into our aligned buffer. Include 3x8 bits of sync word before the preamble
+
+    uint8_t payload_len = message[LENGTH_POS];
+
+    if (payload_len > MAX_LENGTH)
+        return 0; // message junk
+
+    bitbuffer_extract_bytes(bitbuffer, 0, posn + 16, (uint8_t *)&payload, (payload_len + 1) * 8); // we need to include length byte in CRC calc
+
+    // found the polynomial values in an old Semtech application note.
+    uint16_t crc = ~crc16(payload, (payload_len + 1), 0x1021, 0x1d0f) & 0xffff;
+
+    if (((crc >> 8) != message[HEADER_LENGTH + payload_len + 0]) ||
+            ((crc & 0x00ff) != message[HEADER_LENGTH + payload_len + 1])) {
+        fprintf(stderr, "CRC NOT OK!\n");
+        return 0;
+    }
+
+    if (message[NODE_ID_POS] == 0x02) {
+        message[HEADER_LENGTH + payload_len] = 0x00; // remove the checksum which is still at the end of the message buffer
+
+        char strNode[2];
+        char strGateway[2];
+        char strMessage[32];
+
+        sprintf(strGateway, "%d", (message[HEADER_LENGTH]));
+        sprintf(strNode, "%d", (message[NODE_ID_POS]));
+        sprintf(strMessage, "%.30s", &message[DATA_START_POS]);
+
+        /* clang-format off */
+        data = data_make(
+            "model",        "Model",           DATA_STRING, "Moteino-RFM69",
+            "id",           "Node Id ",        DATA_STRING, strNode,
+            "gateway_id",   "Gateway Id",      DATA_STRING, strGateway,
+            "msg",          "Message",         DATA_STRING, strMessage,
+            "mic",          "Integrity",       DATA_STRING, "CRC",
+            NULL);
+        /* clang-format on */
+
+        decoder_output_data(decoder, data);
+
+        return 1;
+    }
+
+    if (message[NODE_ID_POS] == 0xff) // your node id
+    {
+        // Add your own stuff
+    }
+
+    return 0;
+}
+
+static char const *const output_fields[] = {
+        "model",
+        "gateway_id",
+        "id",
+        "msg",
+        "mic",
+        NULL,
+};
+
+r_device const rfm69_lowpowerlab_moteino = {
+        .name        = "RFM69 LowPowerLab Moteino board (-s 1000k)",
+        .modulation  = FSK_PULSE_PCM,
+        .short_width = 18,
+        .long_width  = 18,
+        .reset_limit = 400,
+        .decode_fn   = &rfm69_fsk_callback,
+        .fields      = output_fields,
+
+};