- Miaomiaoce (MMC) 'Smart Temperature and Humidity Meter 3' MJWSD05MMC are hygrometers
- Has onboard clock
- Has sensors to relay temperature and humidity
- Uses Bluetooth Low Energy (BLE) and has a limited range
- A CR2450 coin cell batteries is used as power source
The device uses BLE GATT for communication.
Sensor values are immediately available for reading.
The basic technologies behind the sensors communication are Bluetooth Low Energy (BLE) and GATT. They allow the devices and the app to share data in a defined manner and define the way you can discover the devices and their services. In general you have to know about services and characteristics to talk to a BLE device.
Bluetooth payload data typically uses little-endian byte order.
This means that the data is represented with the least significant byte first.
To understand multi-byte integer representation, you can read the endianness Wikipedia page.
The name advertised by the devices is unknown.
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MIT