ESP32 • IoT Monitor
Platform status, visible away from the screen.
The ESP32 periodically validates the Rejoin BI session and availability. Its LED confirms normal operation or quickly signals when the connection needs attention.
Before you begin
What you need
- ESP32 classic or compatible board
- Wi-Fi 2,4 GHz, with network name and password
- USB for the first flash
- PlatformIO in VS Code or command line
Guided setup
From board to monitoring
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01
Download and extract the package
The ZIP contains the standalone project, source code, declared dependencies and technical manual.
-
02
Flash the firmware
Open the folder in PlatformIO, connect the ESP32 over USB and run the commands below.
platformio run
platformio run --target upload -
03
Join the temporary network
The password is RJ followed by the same 6 characters shown at the end of the network name, always uppercase. You can determine it directly from the Wi-Fi list without using Serial Monitor.
Example:
Network: RejoinBI-IOT-34E3EC
Password: RJ34E3EC
Open: http://192.168.4.1 -
04
Scan and select Wi-Fi
Click Scan networks, choose a 2.4 GHz network, then enter its password, the platform HTTPS address and the check interval.
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05
Sign in to the platform
Use a Rejoin BI account and confirm the PIN when requested. The platform password remains in memory only during sign-in; the device keeps only the authorized session.
-
06
Confirm the LED
After the first validation, the setup portal closes and monitoring runs at the selected interval.
Daily operation
Understand the signals
Wi-Fi, session and platform are working.
Configuring or connecting.
Wi-Fi, session or platform failure.
Change Wi-Fi, interval or LED
With the board already on, hold BOOT for 3 seconds. The temporary network returns without erasing the current session or settings.
Responsible use
Keep HTTPS validation enabled, use a dedicated account with minimum required permissions and physically protect the device. The IoT session does not expire from inactivity; it remains revocable if the account is disabled or removed. The Wi-Fi password and session remain in ESP32 NVS to allow automatic reconnection.