Can I subscribe my channel(s) with MQTT with a free license?

I am using a free license for publishing data with MQTT on ThingSpeak which works very good,

according to the format: channels/<channelID>/publish/fields/field<fieldnumber>.

Can I subscribe my channel(s) with MQTT with a free license with the format:

channels/<channelID>/subscribe/fields/field<fieldnumber>.

Or is there any restriction?

Thanks for your answer and best regards.

[Fred Ettner]

Johan, I'm trying unsuccesfuly to do the same. What micropython MQTT library areyou using?

[Johan Vervaet]

Hello Fred,

I have tried the following even on different micropython versions on ESP32:

1) import upip, upip.install('micropython-umqtt.simple'), upip.install('micropython-umqtt.robust'), or

2) import upip, upip.install('micropython-umqtt.simple2'), upip.install('micropython-umqtt.robust2').

Unfortunately unsuccessfull with the subscribe format channels/<channelID>/subscribe/fields/field<fieldnumber>.

Regards.

Answer 1

[Vinod]

Yes. Even a free license enables you to publish and subscribe to ThingSpeak channels. Note that you may still only publish to a channel once every 15 seconds with a free license.

[Johan Vervaet]

Thank you Vinod for this confirmation.

I am using micropython on ESP32.

I can indeed publish data with MQTT with the format: channels/<channelID>/publish/fields/field<fieldnumber>.

But subscribing with channels/<channelID>/subscribe/fields/field<fieldnumber> fails.

I do not reveive any data.

Can you give me perhaps a working example or more information? Thank you.

[Vinod]

Here's an example that does publish and subscribe on an esp8266:

https://www.mathworks.com/help/thingspeak/use-arduino-client-to-publish-to-a-channel.html

[Johan Vervaet]

Hello Vinod,

I appreciate your answer very much, but unfortunately I am not using ESP8266 on arduino.

I am using ESP32 on Thonny IDE with micropython: do you have any information for that environment?

Thanks and best regards.

[Vinod]

I'm not familiar with that environment, unfortunately. Have you tried subscribing to your channel using a desktop client like mqttx and publishing data to it?