Design of a TFT-LCD Based Digital Automobile Instrument

Table 1

Classification of input signals.

Signal type	Description of the signal
Square wave signal	Signal coming from the tachometer. It can be of high resistance too.
Switching signal	It acts as a trigger signal to trigger some events such as waking up the MCU.
Resistance signal	Signal of the fuel and air volume.
Analog voltage signal	Signal of battery voltage and air pressure.
Differential signal	Signal on the CAN bus. Information of the tachometer, speedometer, oil pressure, and so forth are all sent to the instrument cluster via CAN bus.