Fail to send webhook to ThingSpeak problem?

I have successfully connected a Heltec Cubecell Capsule with CCS811 sensor via HT-M00 gayway to TTN. I tried to setup a webhook to forward sensor payload (6 bytes) to ThingSpeak. I followed the ThingSpeak integration instructions, entered the correct channel ID, write API key and payload formmatter.

I am getting error message:
Fail to send webhook – Error:undefined:undefined. I am not sure what is not defined?
Here are meta data:

“data”: {
@type”: “”,
“namespace”: “pkg/applicationserver/io/web”,
“name”: “request”,
“message_format”: “request”,
“correlation_id”: “96eebdc5efb74a44ae5b388754c2ea35”,
“code”: 14,
“details”: [
@type”: “”,
“value”: {
“body”: “error_bad_request”,
“status_code”: 400,
“url”: “”,
“webhook_id”: “ccs811-m00a-ttn-ts1”

I don’t know how to interpret the meta data to figure out what is wrong with the ThingSpeak webhook integration. Can some one help?


No, no one can help. The HT-M00 is a dual channel packet forwarder, the bigger brother of the equally unsupported single channel packet forwarder, or SCPF, which is not a compliant gateway that causes disruption to the community network and generally doesn’t work properly for the owner either.

See: Single Channel Packet Forwarders (SCPF) are obsolete and not supported

Whilst your issue is not related, we would ask you to disconnect the DCPF immediately and when you have a compliant gateway, we can help you with your webhook issue.

Hi Descartes:
Thank you for your quick response. I need a low cost indoor gateway to evaluate LoRaWAN based sensor network with only a few sensor nodes (for proof of concept).

Is the Heltec HT-M01S a good choice? The spec looks good and price is reasonable.
I like to use Heltec product because my sensor nodes are mostly based on Heltec LoRa boards. It makes integration between sensor nodes and gateway easier.

Thank you again for your help!


Don’t know, not used one, it’s double the price of a TTIG which is pretty much the same hardware.

As to the spec, all gateways use the exact same Semtech chips in, so the radio specs are the same, you are paying for build quality, firmware, enclosure and the antenna.

Completely irrelevant - the LoRaWAN spec means a gateway is a gateway and a device is a device - there’s nothing extra to be had by using the same manufacturer for gateway & device beyond having just one place to ask questions.

Done. Thanks. Ordered one TTIG from Amazon. Will find out how easy to integrate several LoRaAWN sensors soon.

Good stuff!

Thinking about the wording, there’s no actual integration between devices and gateway - the gateway is merely a dumb media convertor, taking appropriately formatted radio waves and sending them on to the network server.

In TTS parlance, integration is the link between the application server and your end point - it’s how you collect the data coming out.

Received the TTIG yesterday. Setup was easy and it was connected to the TTN now.

I setup my CCS811 sensor node (cubeCell capsule) as an end device. The device setup was completed and the sensor node sent out join request with “system provided” DevEui, AppEui & AppKey (in OTAA mode). From TTN application live data, I can see the “joint request” is accepted and forwarded. But the sensor node continuously showed “join failed” every 30 seconds.

Any suggestions?

How far apart is the TTIG and the CCS811?

If too close, the transmissions can swamp the other ends receiver input - consensus is 5m & a brick wall separation for setup.