PKE system consists of host and vehicle key. The host drives the low-frequency transmission circuit, Transmit 125 kHz low-frequency signal to the surrounding at fixed time (Manchester code), used to wake up the car key. The car key uses Ruigan AS3933 to form a low-frequency receiving circuit, and the Bluetooth communication uses angruiwei HS6621CM. When receiving the wake-up signal with the signal frequency of 125kHz, the Bluetooth chip of the car key wakes up, the car key opens the Bluetooth external broadcast data, and the host Bluetooth receives the car key broadcast data, and performs the corresponding decoding and action. The two systems complete the connection handshake through low frequency and carry out data communication through Bluetooth. The scheme has simple structure, flexible function expansion, safety and reliability, and has strong practicability。
Ø Low power RFID Technology: 125kHz low frequency wake-up can save sleep power consumption at the key end. Low frequency signal transmission adopts space alternating magnetic field to realize coupling, and the transceiver couples the electromagnetic field energy transmitted by the base station / vehicle body as its own energy, so it does not need additional power consumption before waking up；
Ø The key / low frequency receiver adopts programmable digital filter wake-up technology. The digital part is always in sleep mode, and is awakened only when the analog part finds a valid input signal. This input signal can be programmed to be free from the interference of other external noise signals and will not be awakened frequently in the complex alternating magnetic field environment；
Ø Low frequency omnidirectional antenna technology: the frequency is always inversely proportional to the antenna size. The key is generally small in size and does not have fixed directivity, so a small omnidirectional antenna design is required when designing the antenna for it. Three pairs of antennas are placed in three orthogonal directions to receive omnidirectional spatial signals。
Ø The receiving distance of low-frequency signal can be controlled at 1-2.5m, and the actual distance depends on the antenna coupling degree and the actual installation position of the antenna；
Ø The key end main control ble module starts broadcasting connection only after the low-frequency signal matches and wakes up；
Ø After low-frequency wake-up, ble 5.0's unique safety connection certification function can improve vehicle anti-theft and safety；
Ø Optional rolling code technology can add additional security
Ø Power supply：5V
Ø Quiescent current：3uA （Key）
Ø Remote control distance：≥10m
Ø PKE sensing distance：≥1.5m
Ø LF working frequency：125kHz
Ø Host interface：RS485（Host）/UART
