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95 results for ESP32 & IoT Builders
How can I make a battery-powered ESP32 Wi-Fi sensor last for months instead of days?
My ESP32 temperature node runs from a 2000 mAh lithium cell and sends one reading over Wi-Fi every 10 minutes. It stays connected all the time, and the battery is flat in under two days. I have seen claims of months of battery life with the same chip. How is …
What is the best way to get Wi-Fi credentials onto a headless ESP32 product: SoftAP, BLE or SmartConfig?
I am turning an ESP32 prototype into a small product. Until now the SSID and password have been hard-coded in the firmware, which obviously cannot ship. The device has no display and only one button. I have seen SoftAP with a web page, provisioning over …
ESP32 MQTT client keeps disconnecting and reconnecting every few seconds: what causes it?
My ESP32 sketch uses the PubSubClient library to publish sensor data every 30 seconds. The serial log shows the connection dropping and being re-established again and again, sometimes every few seconds, and larger JSON messages never arrive at the broker at …
How can I get data from old Modbus RTU machines into an IIoT platform without changing the PLC?
… PLC with a spare RS-485 port that speaks Modbus RTU, some have only a relay panel with no communication at all. The machine builder is gone, and nobody wants to modify the PLC programs. I need running status, cycle counts and energy use from each machine in a …
What is the MQTT Last Will and Testament for, and how do I show devices as online or offline?
I have about 30 ESP32 nodes publishing to a Mosquitto broker and a dashboard that should show which nodes are alive. At present I guess from the time of the last reading, which is unreliable because some nodes only publish on change. I have read that the Last …