ADXL is an accelerometer sensor used to take a signal based on human gestures, it needs a calibration to adjust in order to get a signal from sensor for different motions. In this article we are going to discuss about calibration process using 8051 microcontroller.
In 8051/52 architecture doesn’t have Analog to Digital converter, so need to interface an ADC feature to your circuit. LM324 is an OpAmp based comparator IC, which can convert analog voltage to digital.
Connect ADXL X axis pin with OpAmp 3,4 and Y axis to OpAmp 1 and 2. Hold the sensor in straight position and calibrate for that condition as 0101 using POT and LED’s. Once this calibration is done, you can get the values for other movements also.