Troubleshooting sending message to channel

[cahofmeyr]

Hi there, thanks for this amazing project!

I am modifying the firmware for a ranch IoT use case, and am trying to debug why messages appear not to be transmitting correctly.

I configured a channel 1 with the same name and key on two Heltec Lora32 V3 devices running the same build of Meshtastic.

When I send a message using the CLI from one of the devices, it correctly shows up as a message on channel 1 on the other device:
meshtastic --sendtext "Hello world" --ch-index 1

Now for sending the message from the firmware code. I added the following function in the firmware:

void sendMessage(const char *message) {
    if (!message) return; // Prevent null pointer issues
    meshtastic_MeshPacket *p = router->allocForSending();
    p->channel = 1; 

    // Ensure the message fits within the buffer
    size_t messageLength = strlen(message);
    if (messageLength > sizeof(p->decoded.payload.bytes)) {
        messageLength = sizeof(p->decoded.payload.bytes); // Truncate if necessary
    }

    // Set the payload size and copy the message into it
    p->decoded.payload.size = messageLength;
    memcpy(p->decoded.payload.bytes, message, messageLength);

    service->sendToMesh(p);
}

Looking at the logs using the serial monitor, it looks like the message is transmitted correctly: (stripped some of the log entries for brevity)

DEBUG | 19:30:36 224 Add packet record (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=3 Ch=0x1 Portnum=0 rxtime=1738524636)
DEBUG | 19:30:36 224 Use AES128 key!
DEBUG | 19:30:36 224 enqueue for send (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=3 Ch=0x1f encrypted len=32 rxtime=1738524636 hopStart=3 priority=64)
DEBUG | 19:30:36 224 txGood=12,txRelay=3,rxGood=26,rxBad=2
INFO  | 19:30:37 225 Tell client we have new packets 40
DEBUG | 19:30:37 225 [RadioIf] Started Tx (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=3 Ch=0x1f encrypted len=32 rxtime=1738524636 hopStart=3 priority=64)
DEBUG | 19:30:37 226 [RadioIf] Packet TX: 477ms
DEBUG | 19:30:37 226 [RadioIf] FromRadio=STATE_SEND_PACKETS
DEBUG | 19:30:37 226 [RadioIf] 0 packets remain in the TX queue
INFO  | 19:30:38 226 To Radio onwrite
DEBUG | 19:30:38 226 New ToRadio packet
...
DEBUG | 19:30:38 227 [RadioIf] Completed sending (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=3 Ch=0x1f encrypted len=32 rxtime=1738524636 hopStart=3 priority=64)
...
DEBUG | 19:30:41 230 phone downloaded packet (id=0x72463eb0 fr=0x455560c8 to=0xffffffff, WantAck=0, HopLim=1 Ch=0x0 Portnum=67 rxtime=1738524640 rxSNR=-11.75 rxRSSI=-118 hopStart=
DEBUG | 19:30:42 231 [RadioIf] Lora RX (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=2 Ch=0x1f encrypted len=16 rxSNR=6.75 rxRSSI=-33 hopStart=3)
DEBUG | 19:30:42 231 [RadioIf] Packet RX: 354ms
DEBUG | 19:30:42 231 [RadioIf] rx_snr found. hop_limit:0 rx_snr:-11.750000
DEBUG | 19:30:42 231 [RadioIf] rx_snr found in packet. Setting tx delay:1386
DEBUG | 19:30:43 232 [Router] Rx someone rebroadcasting for us (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=2 Ch=0x1f encrypted len=16 rxSNR=6.75 rxRSSI=-33 hopStart=3)
DEBUG | 19:30:43 232 [Router] Didn't find pending packet
DEBUG | 19:30:43 232 [Router] Found existing packet record for fr=0x43b67b08,to=0xffffffff,id=0x21daeb8b
DEBUG | 19:30:43 232 [Router] Add packet record (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=2 Ch=0x1f encrypted len=16 rxSNR=6.75 rxRSSI=-33 hopStart=3)
DEBUG | 19:30:43 232 [Router] Ignore dupe incoming msg (id=0x21daeb8b fr=0x43b67b08 to=0xffffffff, WantAck=0, HopLim=2 Ch=0x1f encrypted len=16 rxSNR=6.75 rxRSSI=-33 hopStart=3)
DEBUG | 19:30:43 232 [Router] cancelSending id=0x21daeb8b, removed=0
DEBUG | 19:30:43 232 [Router] Incoming msg was filtered from 0x43b67b08

However, the test messages are not showing up on the other device on channel 1 (as seen on the OLED display and in the iOS app).

Any advice on how I can troubleshoot where the problem is or ideas on how to fix this?

Thank you :)

[GUVWAF]

Hey, for it to show up as a text message, you have to set its port number to the text message app:
p->decoded.portnum = meshtastic_PortNum_TEXT_MESSAGE_APP.

[cahofmeyr]

Ah, I missed that. Thank you!

[thebentern]

@cahofmeyr if you're on our discord, I'd love to hear more about your use case and how you plan to integrate meshtastic into it.

[cahofmeyr]

Okay cool, I just joined the Discord server (my user name is conrad)