Battery-powered (Li-ion, 18650) measuring data logger that measures the current relative humidity in %, the current temperature in °C, and calculates the dew point temperature in °C from these. It performs measurements with the specified scheduling and transmits them to a server via ESP-Now (RF) connection.
With ESP32 WROOM32D microcontroller, and AHT10 humidity sensor, 18650 Li-ion battery, built-in battery charger (+5V), Wi-Fi antenna.
Waking up from SLEEP, the ESP32 performs a measurement with the AHT10 humidity sensor (I2C), calculates the dew point (condensation) temperature based on the relative humidity and current temperature, and then transmits the 3 data items to a server via ESP-Now, a long-range 2.4 GHz RF connection. Then the processor goes back to SLEEP. Since the entire described process happens in a fraction of a second, and there is a minimum 1-minute pause between two samples, the average consumption is minimal. The tested distance of the RF connection with a short Wi-Fi stick antenna – in case of physical line of sight – is slightly more than 1 km!
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