Category: Hardware
Product Number: ADXL375
Hello,
I am working on ADXL375 and interfacing it with Arduino UNO using I2C protocol. I get the values of X, Y, Z axis as mentioned in the datasheet, i.e., when placed horizontally I get x=0g, y=0g, z=1g (approx. calibrated). I have enabled trigger mode and mapped interrupt to INT2. My Shock Threshold is set to 0x28 = 31.2g, and I am detecting for single shock event
When I tap the module on table, interrupt triggers even though the threshold is 31.2g, but the values I get are unchanged (around x= 0, y=0, z=1). How to get the values of X, Y, Z during the shock? When I tilt the module, I can see the values change accordingly. but these values hardly go beyond 3g. what am I doing wrong?
Here is my code setup:
/*START Set Shock Threshold*/ Wire.beginTransmission(Device_Address); Wire.write(0x1D); //Shock Duration Register Address Wire.write(0x28); //Scale Factor is 780mg/LSB, hence 0x28 = 31.2g Wire.endTransmission(); /*END Set Shock Threshold*/ /*START Set DUR Thresh_SHOCK*/ Wire.beginTransmission(Device_Address); Wire.write(0x21); //Shock Duration Register Address Wire.write(0x50); //Scale Factor is 625us/LSB, hence 0x50 = 50ms Wire.endTransmission(); /*END Set DUR Thresh_SHOCK*/ /*START Set Latency*/ Wire.beginTransmission(Device_Address); Wire.write(0x22); //Latent Register Address Wire.write(0x20); //Scale Factor is 1.25ms/LSB, hence 0x20 = 400ms Wire.endTransmission(); /*END Set Latency*/ /*START Set Shock Window to 300ms*/ Wire.beginTransmission(Device_Address); Wire.write(0x23); //Window Register Address Wire.write(0xF0); //Scale Factor is 1.25ms/LSB, hence 0xF0 = 300ms Wire.endTransmission(); /*END Set Shock Window to 300ms*/ /*START Enable XYZ-Axis Shock Detection START*/ Wire.beginTransmission(Device_Address); Wire.write(0x2A); //SHOCK_AXES Register Wire.write(0x07); //Enable SHOCK_X, SHOCK_Y, SHOCK_Z Wire.endTransmission(); /*END Enable XYZ-Axis Shock Detection END*/ /*START Set Out-Data-Rate(ODR) to 3200Hz*/ Wire.beginTransmission(Device_Address); Wire.write(0x2C); //BW_RATE Register Address Wire.write(0x0F); //3200 Hz Output Data Rate Wire.endTransmission(); /*END Set Out-Data-Rate(ODR) to 3200Hz */ /*START Enable Single Shock Interrupt*/ Wire.beginTransmission(Device_Address); Wire.write(0x2E); //INT_Enable Register Address Wire.write(0x40); //Enable Single Shock Int Wire.endTransmission(); /*END Enable Single Shock Interrupt*/ /*START Assign Single Shock Interrupt*/ Wire.beginTransmission(Device_Address); Wire.write(0x2F); //INT_Map Register Address Wire.write(0x40); //Assign Single Shock Int Wire.endTransmission(); /*END Assign Single Shock Interrupt*/ /*START Data Format*/ Wire.beginTransmission(Device_Address); Wire.write(0x31); //DATA_FORMAT Reg Wire.write(0x0B); Wire.endTransmission(); /*END Data Format*/ /*START Enable Trigger Mode*/ Wire.beginTransmission(Device_Address); Wire.write(0x38); //FIFO_CTL Register Address Wire.write(0xEA); //Enable Trigger Mode, set samples = 10 Wire.endTransmission(); /*END Enable Trigger Mode*/ /*START Offset Calibration*/ // Scale Factor = 0.196g/MSB Wire.beginTransmission(Device_Address); Wire.write(0x1E); //OFSX Address Wire.write(0xFA); //OFSX offset Wire.endTransmission(); Wire.beginTransmission(Device_Address); Wire.write(0x1F); //OFSY Address Wire.write(0xFB); //OFSY offset Wire.endTransmission(); Wire.beginTransmission(Device_Address); Wire.write(0x20); //OFSZ Address Wire.write(0xFF); //OFSZ offset Wire.endTransmission(); /*END Offset Calibration*/ /*Start Enable Measuring*/ Wire.beginTransmission(Device_Address); Wire.write(0x2D); //POWER_CTL Register Wire.write(0x08); //Enable Measuring Wire.endTransmission(); /*END Enable Measuring*/ /*Attach Interrupt to Digital pin 2*/ attachInterrupt(digitalPinToInterrupt(2), ISR_Func, RISING);
Here is how I am receiving the values:
int16_t data_x = 0, data_x_lsb = 0;
int16_t data_y = 0, data_y_lsb = 0;
int16_t data_z = 0, data_z_lsb = 0;
Wire.beginTransmission(Device_Address);
Wire.write(0x32); //read LSB
Wire.endTransmission();
Wire.requestFrom(Device_Address, 6);
while (Wire.available()) {
data_x_lsb = Wire.read();
data_x = Wire.read();
data_y_lsb = Wire.read();
data_y = Wire.read();
data_z_lsb = Wire.read();
data_z = Wire.read();
data_x = (data_x << 8) | (data_x_lsb);
data_y = (data_y << 8) | (data_y_lsb);
data_z = (data_z << 8) | (data_z_lsb);
}
data_x = (double)data_x*49/1000
data_y = (double)data_y*49/1000
data_z = (double)data_z*49/1000
Sample output:
14:36:51.120 -> -0.072 -0.067 0.977 14:36:51.221 -> -0.087 -0.096 0.949 14:36:51.325 -> 0.010 -0.191 0.988 14:36:51.427 -> -0.062 -0.162 1.071 14:36:51.536 -> -0.010 -0.088 1.071 14:36:51.614 -> -0.015 -0.037 1.052 14:36:51.725 -> -0.022 -0.047 1.044 14:36:51.837 -> 0.062 -0.043 1.012 14:36:52.025 -> FIFO STATUS REG: A0 14:36:52.025 -> Shock Occured 14:36:52.062 -> ACT STATUS SHOCK REG: 1 14:36:52.062 -> INT_SOURCE: C3 14:36:52.137 -> 0.055 -0.081 0.997 14:36:52.252 -> 0.024 0.031 1.033 14:36:52.354 -> 0.011 -0.072 1.079 14:36:52.455 -> 0.022 -0.031 0.973 14:36:52.547 -> 0.014 -0.042 1.041 14:36:52.654 -> -0.062 -0.036 1.018 14:36:52.770 -> -0.080 -0.003 1.003 14:36:52.880 -> -0.081 -0.118 1.084 14:36:52.972 -> -0.080 -0.039 1.046 14:36:53.079 -> -0.109 -0.016 0.930
edited code
[edited by: RajT at 1:29 PM (GMT -5) on 24 Jan 2023]
