Need help with my first TTN node

Hi TTN community,

Please help with building and programming my first TTN node.

The hardware is:

  • Arduino Uno R3
  • Adafruit RFM95W LoRa Transceiver Breakout with 868 Mhz

The IDE is Arduino v1.8.9 with newest arduino-lmic-master library installed!

I used this tutorial:
https://www.mobilefish.com/developer/lorawan/lorawan_quickguide_build_lora_node_rfm95_arduino_uno.html

This is how the circuit looks like at the moment:
TTN-Test-Node%20v1

Pin mapping is in the schematics as well.

Node is registered with TTN and I tried the ttn-abp example in Debug Mode 2.

No error messages during compilation and upload.

This is what I always see in the terminal window:

08:07:58.915 -> Starting
08:07:58.962 -> RXMODE_RSSI
08:07:58.962 -> 78: irq: dio: 0x1 flags: 0x0
08:07:58.962 -> 114: Scheduled job 0x25d, cb 0 ASAP
08:07:58.962 -> 184: Cleared job 0x25d
08:07:58.962 -> 401: engineUpdate, opmode=0x808
08:07:58.962 -> 472: Uplink data pending
08:07:58.962 -> 605: Considering band 0, which is available at 398
08:07:59.009 -> 876: Considering band 3, which is available at 0
08:07:59.009 -> 1141: No channel found in band 3
08:07:59.009 -> 1311: Considering band 0, which is available at 398
08:07:59.009 -> 1594: No channel found in band 0
08:07:59.009 -> 1763: Considering band 1, which is available at 398
08:07:59.009 -> 2040: Airtime available at 398 (channel duty limit)
08:07:59.009 -> 2315: Ready for uplink
08:07:59.009 -> 2847: Updating info for TX at 471, airtime will be 3856. Setting available time for band 1 to 3826712576
08:07:59.009 -> 3099: TXMODE, freq=867300000, len=26, SF=7, BW=125, CR=4/5, IH=0
08:07:59.009 -> Packet queued
08:07:59.009 -> 3202: irq: dio: 0x1 flags: 0x0
08:07:59.056 -> 3371: Scheduled job 0x25d, cb 0xf11 ASAP
08:07:59.056 -> 3584: Running job 0x25d, cb 0xf11, deadline 0
08:07:59.056 -> 3830: Scheduled job 0x25d, cb 0xf24 at 62869
08:07:59.056 -> 4073: irq: dio: 0x1 flags: 0x0
08:07:59.056 -> 4235: Cleared job 0x25d
08:07:59.056 -> 4295: Scheduled job 0x25d, cb 0xf24 ASAP
08:07:59.056 -> 4513: Running job 0x25d, cb 0xf24, deadline 0
08:07:59.056 -> FAILURE
08:07:59.056 -> C:\Users\gknese\Documents\Arduino\libraries\arduino-lmic-master\src\lmic\radio.c:660

Please help

Kind regards
Gerd Knese

You have DIO1 on the RFM95 connected to the TXD pin on the UNO, thats used by the UNOs program uploader and for sending output to the serial monitor.

Put DIO1 on an unused pin.

1 Like

Hi LoRaTracker,

Uh, yes you are fully correct.

I changed this to D5 and it’s running now.

Thanks a lot
Gerd

Wise to start on the assumption that the tutorial is correct, it had DIO1 connected to pin 5.

Fully correct, but sometimes we lose sight of the wood for the trees. I started with the Adafruit tutorial first and mixed them up.
Big mistake! :rofl: