Design of High Precision Power Consumption Instrument Based on SEP3203

A design method based on ARM processor of multichannel high precision data acquisition unit is introduced in this article.Physical quantity such as voltage,current,thermo resistance,thermocouple and switching value can be measured by this unit.Data is transferred through simulative SPI protocol between ARM and data acquisition module.To achieve high precision,A 24 bit A/D is used.Now one out of ten thousand precision can be achieved after several times of improvements of the circuit and the precision is better than present industry standard.