A design of a low cost high precision data acquisition system

The paper presents a high precision data acquisition system with the LM231 V/F transform chip and a low cost single chip microcomputer. The V/F transformer features high precision, high linearity and with a simple peripheral circuit. The single chip microcomputer is connected directly to an interface with the LM231 chip that has a lower-power coupling circuit, to improve the system working reliability. Fully utilised the hardware and software resources, the system identifier rate reaches 12 digits and its accurate is 0.02%. The system is available for use in the field of measurements of a weighing system, voltage, current intensity, methane density, etc. In the case of long connecting distance between the sensors and upper computer, the RS-485 interface or wireless data transmitting/receiving module can be used to realise remote data communication.