--- /dev/null
+/* OpenEnergyMonitor.org emonTx sensor protocol
+ *
+ * Copyright © 2016 Tommy Vestermark
+ * Copyright © 2016 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 "util.h"
+
+// We don't really *use* this because there's no endianness support
+// for just using le16_to_cpu(pkt.ct1) etc. A task for another day...
+struct emontx {
+ uint8_t syn, group, node, len;
+ uint16_t ct1, ct2, ct3, ct4, Vrms, temp[6];
+ uint32_t pulse;
+ uint16_t crc;
+ uint8_t postamble;
+} __attribute__((packed));
+
+// This is the JeeLibs RF12 packet format as described at
+// http://jeelabs.org/2011/06/09/rf12-packet-format-and-design/
+//
+// The RFM69 chip misses out the zero bit at the end of the
+// 0xAA 0xAA 0xAA preamble; the receivers only use it to set
+// up the bit timing, and they look for the 0x2D at the start
+// of the packet. So we'll do the same — except since we're
+// specifically looking for emonTx packets, we can require a
+// little bit more. We look for a group of 0xD2, and we
+// expect the CDA bits in the header to all be zero:
+static unsigned char preamble[3] = { 0xaa, 0xaa, 0xaa };
+static unsigned char pkt_hdr_inverted[3] = { 0xd2, 0x2d, 0xc0 };
+static unsigned char pkt_hdr[3] = { 0x2d, 0xd2, 0x00 };
+
+static int emontx_callback(bitbuffer_t *bitbuffer) {
+ bitrow_t *bb = bitbuffer->bb;
+ unsigned bitpos = 0;
+ unsigned bits = bitbuffer->bits_per_row[0];
+ int events = 0;
+
+ // Search for only 22 bits to cope with inverted frames and
+ // the missing final preamble bit with RFM69 transmissions.
+ while ((bitpos = bitbuffer_search(bitbuffer, 0, bitpos,
+ preamble, 22)) < bitbuffer->bits_per_row[0]) {
+ int inverted = 0;
+ unsigned pkt_pos;
+ uint16_t crc;
+ data_t *data;
+ char time_str[LOCAL_TIME_BUFLEN];
+ union {
+ struct emontx p;
+ uint8_t b[sizeof(struct emontx)];
+ } pkt;
+ uint16_t words[14];
+ double vrms;
+ unsigned i;
+
+ bitpos += 22;
+
+ // Eat any additional 101010 sequences (which might be attributed
+ // to noise at the start of the packet which coincidentally matches).
+ while (bitbuffer_search(bitbuffer, 0, bitpos, preamble, 2) == bitpos)
+ bitpos += 2;
+
+ // Account for RFM69 bug which drops a zero bit at the end of the
+ // preamble before the 0x2d SYN byte. And for inversion.
+ bitpos--;
+
+ // Check for non-inverted packet header...
+ pkt_pos = bitbuffer_search(bitbuffer, 0, bitpos,
+ pkt_hdr, 11);
+
+ // And for inverted, if it's not found close enough...
+ if (pkt_pos > bitpos + 5) {
+ pkt_pos = bitbuffer_search(bitbuffer, 0, bitpos,
+ pkt_hdr_inverted, 11);
+ if (pkt_pos > bitpos + 5)
+ continue;
+ inverted = 1;
+ }
+
+ // Need enough data for a full packet (including postamble)
+ if (pkt_pos + sizeof(pkt)*8 > bitbuffer->bits_per_row[0])
+ break;
+
+ // Extract the group even though we matched on it; the CRC
+ // covers it too. And might as well have the 0x2d too for
+ // alignment.
+ bitbuffer_extract_bytes(bitbuffer, 0, pkt_pos,
+ (uint8_t *)&pkt, sizeof(pkt) * 8);
+ if (inverted) {
+ for (i=0; i<sizeof(pkt); i++)
+ pkt.b[i] ^= 0xff;
+ }
+ if (pkt.p.len != 0x1a || pkt.p.postamble != 0xaa)
+ continue;
+ crc = crc16((uint8_t *)&pkt.p.group, 0x1d, 0xa001, 0xffff);
+
+ // Ick. If we could just do le16_to_cpu(pkt.p.ct1) we wouldn't need this.
+ for (i=0; i<14; i++)
+ words[i] = pkt.b[4 + (i * 2)] | (pkt.b[5 + i * 2] << 8);
+ if (crc != words[13])
+ continue;
+
+ vrms = (double)words[4] / 100.0;
+
+ local_time_str(0, time_str);
+ data = data_make("time", "", DATA_STRING, time_str,
+ "model", "", DATA_STRING, "emonTx",
+ "node", "", DATA_FORMAT, "%02x", DATA_INT, pkt.p.node & 0x1f,
+ "ct1", "", DATA_FORMAT, "%d", DATA_INT, (int16_t)words[0],
+ "ct2", "", DATA_FORMAT, "%d", DATA_INT, (int16_t)words[1],
+ "ct3", "", DATA_FORMAT, "%d", DATA_INT, (int16_t)words[2],
+ "ct4", "", DATA_FORMAT, "%d", DATA_INT, (int16_t)words[3],
+ "Vrms/batt", "", DATA_FORMAT, "%.2f", DATA_DOUBLE, vrms,
+ "pulse", "", DATA_FORMAT, "%u", DATA_INT, words[11] | ((uint32_t)words[12] << 16),
+ // Slightly horrid... a value of 300.0°C means 'no reading'. So omit them completely.
+ words[5] == 3000 ? NULL : "temp1_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[5] / 10.0,
+ words[6] == 3000 ? NULL : "temp2_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[6] / 10.0,
+ words[7] == 3000 ? NULL : "temp3_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[7] / 10.0,
+ words[8] == 3000 ? NULL : "temp4_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[8] / 10.0,
+ words[9] == 3000 ? NULL : "temp5_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[9] / 10.0,
+ words[10] == 3000 ? NULL : "temp6_C", "", DATA_FORMAT, "%.1f", DATA_DOUBLE, (double)words[10] / 10.0,
+ NULL);
+ data_acquired_handler(data);
+ events++;
+ }
+ return events;
+}
+
+static char *output_fields[] = {
+ "time", "model", "node", "ct1", "ct2", "ct3", "ct4", "Vrms/batt",
+ "temp1_C", "temp2_C", "temp3_C", "temp4_C", "temp5_C", "temp6_C",
+ "pulse", NULL
+};
+
+r_device emontx = {
+ .name = "emonTx OpenEnergyMonitor",
+ .modulation = FSK_PULSE_PCM,
+ .short_limit = 2000000.0 / (49230 + 49261), // 49261kHz for RFM69, 49230kHz for RFM12B
+ .long_limit = 2000000.0 / (49230 + 49261),
+ .reset_limit = 1200, // 600 zeros...
+ .json_callback = &emontx_callback,
+ .disabled = 0,
+ .demod_arg = 0,
+ .fields = output_fields,
+};
projects / rtl-433.git / blobdiff