Design of Serial/Parallel Communication Interface of Digital Potentiometer with PC
Zhou Wanzhen, Sha Zhanyou, Meng Zhiyong, Yunfeng Xu · 2007
RS-232 serial port of the PC and I2C bus digital potentiometer serial communication can be realized by single-chip microcomputer, PIC16F62 made by Microchip Company and RS-232 voltage converter as the hardware circuitry, its excellence, high run speed, high transmission speed (120 kbps), low power, small bulk, low work voltage, high drive ability etc. Introduced hardware verifies and debugs method. There are two parts of program flow of the software design: one is the communication of PC and PIC16F628, and the other is the communication of PIC16F628 and I2C bus digital potentiometer. Given the example of the communication timing of single-chip micro-computer with I2C bus, and the method of serial communication by the DS2W soft tool between dialog box of the Window and I2C bus digital potentiometer. To realize the communication of PC parallel with I2C bus digital potentiometer, designed one type interface circuitry based on high speed CMOS inverter and Parallel Port soft tool, and insulated the PC parallel circuitry, and turn the TTL level of the parallel to Open-Drain level for the I2C interface, which can take place emulator or evaluate demo board to debug the digital potentiomenter. The designing software should insure to determinant the address of the slave digital potentiomenter. At last given the program and explain of verify and debug the digital potentiomenter by Debug using a typical parallel address. The given design has already validated, and has practical value.