Sending Command to device in Eclipse hono

Question

I'm experimenting with command and control in Hono and got this:=>

Error Message

No credit available for sending request

anyone knows how to deal with this?

Answer 1

It seems that your device is not ready to receive any commands. In case of HTTP, the devices inform their readiness to receive commands using a telemetry or event message with an additional parameter named hono-ttd. Below example illustrates a telemetry message request (to sandbox) with hono-ttd value as 60 seconds using curl.

curl -i -X POST -u sensor1@DEFAULT_TENANT:hono-secret -H 'Content-Type: application/json' --data-binary '{"sensor1": 5}' http://hono.eclipse.org:8080/telemetry?hono-ttd=60

In the above case, after 60 seconds the device is no longer ready to receive any commands.

I would suggest that you first send a request from the device as above with the hono-ttd value. Then try sending a command to that device before expiry of the hono-ttd.