Throttle signal measurement of signal
    Here measurements on a car engine throttle position sensor for an adjustable resistor type, throttle position of the output signal 0 ~ 5V voltage signal, according to the actual throttle opening and the output voltage of the relationship between the voltage signal measurement calibration , according to the measured voltage signal can be converted into the throttle opening. So here PIC18F4580 microcontroller with embedded 10-bit AD conversion circuit to complete the throttle position sensor output voltage measurement, in order to improve the measurement accuracy of the 5V MCU AD reference voltage regulator with the system power isolation processing. The system uses Microchip's MPLAB development environment, compiler, embedded PICC18 C program, using C programming for data acquisition and data transceiver CAN program, in which AD conversion routines written in assembly language, the program takes care of C programs modular and can be maintenance and good benefits, also has the advantages of high efficiency in assembly language. Signals through the CAN controller, using the extended frame format sent to the CAN network. Data Acquisition and CAN in which data is sent subroutine is as follows: Initial (); / / IO port initialization InitUSART (); / / serial port initialization Init TMR0 (); / / Timer 0 Initialization.