Putting WMBus telegram into fhem

[xaelsouth]

Putting WMBus telegram into fhem

[bilbolodz]

I've thought rather about "special FHEM mode". To use your software with FHEM you have to put message in format "b6e4401[rest removed]\n" (Just that string without any additional dates, semicolons etc) into pipe file. Full recipe is:

1. Install FHEM ;-)
2. mkfifo /opt/fhem/CUL_fifo
3. chown fhem:dialout /opt/fhem/CUL_fifo
4. Create "dummy CUL device (via telnet or WWW):

defmod cul_emu CUL /opt/fhem/CUL_fifo@directio 3539
attr cul_emu dummy 1
attr cul_emu rfmode WMBus_T

5. Pipe WMBus telegram into fifo file (that's why I'm asking for special FHEM mode).
6. FHEM should automatically create WMBUS devices. At first time FHEM starts complaing about missing crystallographic perl modules so you will have to full fill all dependencies for WMBUS module but if you know anything about linux it's very easy.
7. Messages could be encrypted in that case you have to define AES key (in my case hopefully it's "standard" 0000..... code

[xaelsouth]

diff --git a/t1_c1_packet_decoder.h b/t1_c1_packet_decoder.h
index ba320f1..2dc77a1 100644
--- a/t1_c1_packet_decoder.h
+++ b/t1_c1_packet_decoder.h
@@ -554,13 +554,13 @@ static void t1_c1_packet_decoder(unsigned bit, unsigned rssi)
                 rssi,
                 get_serial(t1_c1_packet_decoder_work.packet));
 
-#if 0
-        fprintf(stdout, "0x");
+#if 1
+        fprintf(stdout, "b");
         for (size_t l = 0; l < t1_c1_packet_decoder_work.L; l++) fprintf(stdout, "%02x", t1_c1_packet_decoder_work.packet[l]);
         fprintf(stdout, ";");
 #endif
 
-#if 1
+#if 0
         t1_c1_packet_decoder_work.L = cook_pkt(t1_c1_packet_decoder_work.packet, t1_c1_packet_decoder_work.L);
         fprintf(stdout, "0x");
         for (size_t l = 0; l < t1_c1_packet_decoder_work.L; l++) fprintf(stdout, "%02x", t1_c1_packet_decoder_work.packet[l]);

[xaelsouth]

BTW, i am interested in how you have done decoding WMBus telegrams with fhem software. Could you provide a recipe?

[xaelsouth]

diff --git a/t1_c1_packet_decoder.h b/t1_c1_packet_decoder.h
index ba320f1..146ce47 100644
--- a/t1_c1_packet_decoder.h
+++ b/t1_c1_packet_decoder.h
@@ -546,6 +546,7 @@ static void t1_c1_packet_decoder(unsigned bit, unsigned rssi)
     {
         t1_c1_packet_decoder_work.crc_ok = check_calc_crc_wmbus(t1_c1_packet_decoder_work.packet, t1_c1_packet_decoder_work.L) ? 1 : 0;
 
+#if 0
         fprintf(stdout, "%s;%u;%u;%s;%u;%u;%08X;", t1_c1_packet_decoder_work.c1_packet ? "C1": "T1",
                 t1_c1_packet_decoder_work.crc_ok,
                 t1_c1_packet_decoder_work.err_3outof^1,
@@ -553,14 +554,14 @@ static void t1_c1_packet_decoder(unsigned bit, unsigned rssi)
                 t1_c1_packet_decoder_work.packet_rssi,
                 rssi,
                 get_serial(t1_c1_packet_decoder_work.packet));
+#endif
 
-#if 0
-        fprintf(stdout, "0x");
+#if 1
+        fprintf(stdout, "b");
         for (size_t l = 0; l < t1_c1_packet_decoder_work.L; l++) fprintf(stdout, "%02x", t1_c1_packet_decoder_work.packet[l]);
-        fprintf(stdout, ";");
 #endif
 
-#if 1
+#if 0
         t1_c1_packet_decoder_work.L = cook_pkt(t1_c1_packet_decoder_work.packet, t1_c1_packet_decoder_work.L);
         fprintf(stdout, "0x");
         for (size_t l = 0; l < t1_c1_packet_decoder_work.L; l++) fprintf(stdout, "%02x", t1_c1_packet_decoder_work.packet[l]);

[xaelsouth]

See new patch above. Apply the patch, make and then test if it fits your needs with

• cat samples2.bin | build/rtl_wmbus 2>/dev/null

The output should be:
b294468502300207172f03840a0009f21000000a07d220200010000005b94000000000000000004000302030200002b75
b6644242382007064640e0baa721221008492261704300050059de7c9967230894d0d5e5aab82e4d9eefe39d0b338a3c8f936c0db728d6786698b5c0b4b88e516b988611072a991fd1fbfd2a5b8bee9f9c6bf73da0ce56ae94e2cf7c75b250bfd8ed0f2ec1b810b9c5f3adc3f7cfa326857c98da060

I can't test it with FHEM, because samples2.bin contains Techem smoke detector for which FHEM module does not exist. The second line is from W-Mbus converter sitting on heat meter.

Let me know, if the patch from above will help you (or not).

[bilbolodz]

It's working. Now I'm waiting for more messages from meter.