Design of High Precision Electronic Scale Based on MSP430G2

摘要

The resistance bridge is used as a pressure sensor, when the external force is applied to generate 0 ～ 20mV voltage small signal, the precision instrumentation amplifier amplification 51 times, access to 16 bit high precision digital analog conversion (A/D) chip ADS 1146. 16 bit A/D in the input voltage of 3.6V, the minimum resolution of 0.05mV, to achieve high precision pressure sensor signal acquisition, the accuracy can reach 0.1 grams. The A/D conversion to digital quantity through the SPI interface connected to the low power microprocessor msp430g2553, and then sent to the LCD display, through the calibration button and do some simple multiplication and achieve more functional. Test results show that the small signal amplification link can achieve the stability of the signal amplification, and can achieve accurate weighing.