RAK7289C Chirpstack V4 Support

[NTeterski]

Hello,

We have several hundred RAK7289C gateways (not the RAK7289CV2 gateways). These gateways were set up to report to Chiprstack V3 over MQTT. We are currently upgrading our cloud infrastructure and are looking to migrate to Chirpstack V4. The RAK7289C model is on latest firmware. The RAK7289C only natively supports the “MQTT for ChripStack 3.x” Protocol. Chirpstack V4 has a “v4_migrate” option that adds some support to receive messages over “MQTT for ChripStack 3.x (Protobuf)”, but it is meant for the ChirpStack Gateway Bridge v3.14.0+. While this does allow us to recieve messages from ABP activated devices, sending downlinks or join accept messages does not work, because of incompatibilities with how RAK7289C decode the incoming messages. System logs will show an error:

Fri Oct  2 20:58:26 2026 daemon.info gwBridge[14903]: mosqMsgCB topic : us915_1/gateway/ac1f09fffe070343/command/down
Fri Oct  2 20:58:26 2026 daemon.info gwBridge[14903]: gwBridgeParseMosqDownlink mqtt downlink packet - size 254
Fri Oct  2 20:58:26 2026 daemon.info gwBridge[14903]: Pb txinfo is NULL

Looking into the RAK forums, I found a number of similar unresolved issues running into the same error with this configuration (im limited to only 2 links in a post):

Connect RAK7258 to ChirpStack v4?

I am currently my RAK7258 (Firmware: 1.3.6_RAK b150, Mode: Packet Forwarder) with ChirpStack v3 and I would like to upgrade to ChirpStack v4? In the LoRa Network settings I can only select ChirpStack v3. Is it compatible with v4 even when using v3? Or will there be a firmware upgrade in the near future to support v4?

Can't upgrade to Chirpstack v4 - Support new MQTT protocol

Hello RAK team, Chirpstack v4 is nearly released, and we are eager to move to it for it’s enhanced feature set. Unfortunately, some (perhaps just the down link command) of the MQTT Protobuf definitions have changed, and the built-in gateway bridge is not compatible. The changes, from what I can tell, are mostly a reorganization of the parameters. You can find the new definitions here: https://github.com/chirpstack/chirpstack/blob/master/api/proto/gw/gw.proto) Chirpstack’s own gateway bridge w…

Some of these posts mention an upcoming firmware fix to be soon released, but these posts are 3-4 years old with no new firmware available for this model. Is this still a planned fix or has it been abandoned? As mentioned, we have several hundred of these units.