NFC or BLE based contactless lock with charge monitoring of its energy storage

Electronic circuitry for an electronic lock, comprising:

• an antenna configured to receive a signal, the signal configured under the near field communication (NFC) protocol or the Bluetooth low energy (BLE) protocol;
• a communication processor, coupled to the antenna, configured to decrypt the signal to ascertain a command to lock or unlock the electronic lock and to authenticate a source of the signal;
• an energy storage component configured to store electrical energy;
• a motor switch configured to drive a motor clockwise or counterclockwise, powered by the energy storage component, depending on a control signal, wherein the motor switch is configured to drive the motor for a short burst of time;
• and
• a controller, coupled to the energy storage component and the motor switch, configured to monitor electrical charge left in the energy storage component and to output the control signal that corresponds to the command to lock or unlock the electronic lock;
• wherein the communication processor is configured to communicate according to the Bluetooth LE protocol, but with a lower transmission power and/or a diminished receiver sensitivity compared to what is specified in the Bluetooth LE protocol standards.

A method of operating an electronic circuitry for an electronic lock cylinder, comprising:

• receiving a first wireless signal from an external device at a first antenna;
• decoding the first wireless signal to ascertain a command to lock or unlock the electronic lock cylinder and to authenticate a source of the first wireless signal;
• charging an energy storage capacitor with electrical energy harvested through a second antenna, wherein the second antenna is configured to receive a second wireless signal from the source of the first wireless signal, wherein the second wireless signal is at a different frequency than the first wireless signal;
• determining whether the energy storage capacitor has reached a threshold charge;
• in response to determining that the energy storage capacitor has reached the threshold charge, outputting a control signal that corresponds to the command to lock or unlock the electronic lock cylinder;
• and
• driving a motor clockwise or counterclockwise depending on the control signal by discharging the energy storage capacitor.