Initialisation of tyre monitoring devices

An aircraft tyre monitoring device configured to be mounted on a wheel of a vehicle, the tyre monitoring device comprising:

• a wireless communication interface;
• an indicator;
• a pressure sensor;
• a temperature sensor;
• a processing system;
• and
• a power supply;
• wherein the tyre monitoring device is configured to:
• operate in a storage mode in which at least one of the indicator, the pressure sensor;
• the temperature sensor and the processing system cannot be used and the tyre monitoring device is only responsive to an initialisation instruction received over the wireless communication interface;
• and
• operate in a normal mode in response to the initialisation instruction, wherein in the normal mode, the indicator, the pressure sensor;
• the temperature sensor and the processing system can be used and the tyre monitoring device is responsive to instructions received over the wireless communication interface, the storage mode having a lower power requirement than the normal mode.

A tyre monitoring system comprising:

• a plurality of tyre monitoring devices each comprising a wireless communication interface;
• and
• a configuration device comprising a wireless communication interface;
• wherein the plurality of tyre monitoring devices are responsive to an initialization command sent by the configuration device over the wireless communication interface to transition from a power-saving storage mode to a normal operation mode.