Rak 3172 does not to join RAK3172 (RUI 4.2.0) Join Failed (RX_TIMEOUT) with RAK5146 Gateway on ChirpStack v4 US915_0

Amir · April 25, 2025, 4:50pm

Hi RAKwireless team and community,

I’m working on a sports vest project using 15x RAK3172 modules (LoRaWAN OTAA mode) with a RAK5146-based gateway running ChirpStack v4 locally (Docker on Raspberry Pi CM4). The gateway is configured to US915_0 sub-band.

However, I’m consistently getting join failures with +EVT:JOIN_FAILED_RX_TIMEOUT. I’ve tried multiple configurations. Below are the full details of my setup and current status:

RAK3172 Configuration:

Firmware version: RUI_4.2.0_RAK3172-T
Mode: LoRaWAN, OTAA, Class A
Region/Band: US915 sub-band 0
AT Commands:

AT+NWM=1
AT+NJM=1
AT+CLASS=A
AT+BAND=5
AT+MASK=0001
AT+CHE=1:2:3:4
AT+DEVEUI=DD4D23CD367B66A4
AT+APPEUI=9A314E467B84C6A3
AT+APPKEY=FB50868C07B8851EB21670DC986908EA
AT+ADR=0
AT+TXP=14
AT+JOIN

Result: Always +EVT:JOIN_FAILED_RX_TIMEOUT

ChirpStack Gateway & Device Profile:

Gateway: RAK5146 on Raspberry Pi CM4
Region: US915_0 (sub-band 0, channels 8–15)
Packet-forwarder is working (verified via journalctl)
ChirpStack Gateway Bridge running
Device Profile:
- MAC Version: LoRaWAN 1.0.3
- Regional Parameters Revision: RP001-1.0.3-RevA
- RX1 Delay: 1
- ADR: Enabled (also tried disabled)
- Frame-counter validation: Disabled
- Flush queue on activation: Yes
  
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beegee · April 26, 2025, 2:36am

Confusing information

subband 0 would be channels 0-7

channels 8-15 would be subband 1

Your node is setup to channels 0-7, not for channels 8-15
You Chirpstack is setup to channels 8-15, not to channels 0-7

Make sure all devices are setup to the same channels, the RAK3172, the gateway and your LNS.

thejbte · September 4, 2025, 9:36pm

I had a similar problem (+EVT:JOIN_FAILED_RX_TIMEOUT). My LG308N was registered to TTN, but the RF Frequency Plan was still EU868. Since my node was transmitting on US915, the gateway was basically deaf. After switching the gateway RF plan to US915 FSB2, the node and gateway matched TTN’s frequency expectations, and the Join-Accept worked right away and I could also send uplink messages without issues.