Geert Esselens asked 5 years ago
The whole course as been very nice! Thank you for this.
I am playing with the mqqt protocol. Completed this course with a light measurement sensor and it worked fine with a graph on the portal from the node-red.
Now I want to add a distance sensor and include it in the webportal. The sensor works fine in the serial monitor but If I just copy the publish code and chance the topic I get the error: “redeclaration of uint16_t packetIdPub2?
So essentially I have :
uint16_t packetIdPub2 = mqttClient.publish(“SLITTER/light”, 2, true, LightString.c_str()); //which works fine
uint16_t packetIdPub2 = mqttClient.publish(“SLITTER/distance”, 2, true, DistanceString.c_str());//which is a redeclaration?
I do not fully understand the syntax of this publishing?
All help is welcome,
Geert
ps: I am not using a pure ESP32 but playing with the M5GO (fire) but absolutely no issue during the full course.
Rui Santos Staff answered 5 years ago
Hi Geert, you need to use something like this (create a new unit16_t variable):
uint16_t packetIdPub2 = mqttClient.publish("SLITTER/light", 2, true, LightString.c_str()); //which works fine
uint16_t packetIdPub3 = mqttClient.publish("SLITTER/distance", 2, true, DistanceString.c_str());
Parameters:
- Topic name
- Quality of service
- Retain message (yes=true)
- Message
Thanks for letting me know! Yes, all ESP32 boards should be compatible with the course if you always double-check the pin assignment!
Geert Esselens answered 5 years ago
Perfect, that works golden.
Now the sensors are nicely available.
At this moment they are connected to different ESP32’s and publish correctly to the server.
Regards
Geert
Rui Santos Staff answered 5 years ago
I’m glad it worked! You can simply create more uint16_t packetIdPub3, uint16_t packetIdPub4 and so on for the next topics that you want to publish.
Regards,
Rui