May 18, 2023 · How to use Arduino opta to send mqtt signals hello all, I'm still learning how to use the Arduino opta and I am doing a project on in it so I need more information and how to test the IDE …

Jun 20, 2023 · Hi, I have ESP32-CAM and SIM800L module and I want to send an image via MQTT. But there is an limit for the each package in "PubSubClient.h". I can send the image with 128 bytes …

Jun 3, 2025 · Hey all. I'm pretty new to MQTT so was wondering if I can get some help with diagnosing a connectivity issue. My setup is as follows: 2 units of Ardino Mega with Ethernet Shield 2 each Home …

Jul 5, 2024 · I am trying to put together a simple ESP-01 based monitoring device and I want it to simply send a MQTT message to my MQTT broker every time a reed switch closes. The closures are about …

Jun 1, 2023 · Here is an old thread about a similar problem. You can check this out: ESP8266 can't connect to MQTT broker - #12 by ducle27

Oct 15, 2018 · You do not call callback from loop (), it is called by the MQTT library code when your Arduino receives an MQTT message on a topic you have subscribed to. You don't seem to be …

Apr 27, 2025 · I've been out of the scene for quite some time for personal reasons. Trying to get back into things that make me happy. I need help with this sketch. I think the errors may be due to …

Dec 4, 2020 · How is it possible arduino (esp32) to connect to MQTT server on the SSL port without providing any cert files but mosquitto_pub not to connect? What am I missing?

Dec 2, 2024 · There is NO non-blocking mqtt. Since mqtt uses wifi, you may be able to rewrite the mqtt client to use a non blocking wifi connect but since that's a board level library, it may not be possible.

Jan 4, 2022 · Hi i am new to working with Arduino and c/++ but i am working on a small project that uses MQTT i have setup a test MQTT server on the lan, and i can see the connection attempt from the …