Payload Message sent by uplink in the Gateway

Hi, i’m trying to understand the way to read the values that uplink the tags in the range of the Gateway, the message has this topology (or Payload?) :


Picture to understand:

So i want to know the function that writes this or how can i read/write this.
Im using C to read this message, but cant do it at the moment.

Hi FrancoCapararoArg,

1, This messages are in Json fomat, if you are using C , please search Cjson , there are many open source Cjson source file, you only need add the source file in your project.
2, In our project, just use mmap/fread/fwrite/ to operate the file according to the directory you showed in the picture.



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yes, but when i write in Json format, i cant receive nothing… just a /node/uplink/status saying “false”.

Hi Franco,

what do you mean with writing? Do you mean to publish data to the node? If so, you need to publish to the downlink topic, see this post:

Another MQTT library option is to use Mosquitto libraries:


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