This article describes the SCM combined with A/D converter and wireless digital transmission module which is used for building a DC voltage measurement system based on LabVIEW. The system uses AT89C52 as controller, ICL7135 as precision, double integral A/D converter circuit as voltage data collection, PTR2000 as a wireless transmission module and the LCD display module as the measured voltage. The collected data can be transmitted to a PC. The hardware system design of the DC digital voltmeter is introduced exhaustively. It also gives some details of the hardware circuit design.
