[英]ADXL375Z Shock Threshold False Triggering
我正在研究 ADXL375 並使用 I2C 協議將其與 Arduino UNO 連接。 我得到數據表中提到的 X、Y、Z 軸的值,即,當水平放置時,我得到 x=0g、y=0g、z=1g(近似校准)。 我已啟用觸發模式並將中斷映射到 INT2。 我的沖擊閾值設置為 0x28 = 31.2g。
當我點擊桌子上的模塊時,即使閾值是 31.2g,中斷也會觸發,但我得到的值沒有改變(大約 x= 0,y=0,z=1)。 沖擊過程中如何得到X、Y、Z的值? 當我傾斜模塊時,我可以看到值相應地發生變化。 但這些值幾乎沒有超過 3g 的 go。 我究竟做錯了什么?
這是我的寄存器代碼設置:
/*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*/
//Used for Double Shock Detection Only**
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);
這是我接收值的方式:
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
樣本 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
根據數據表,它說我們需要在每次觸發事件后重置觸發模式。 我嘗試這樣做但無濟於事。
我正在使用 I2C 進行多字節讀取,並實現了跨度為 4 的移動平均濾波器。
更新:我能夠獲得 output 值。 我所要做的就是通過在初始設置中進入旁路模式來重置觸發模式。 並在每次沖擊事件后再次重置。
這是我在設置中添加並在每次沖擊事件后調用的代碼部分。
/*START Disable Trigger Mode/enable Bypass Mode*/
Wire.beginTransmission(Device_Address);
Wire.write(0x38); //FIFO_CTL Register Address
Wire.write(0x2A); //Disable Trigger Mode, set samples = 10
Wire.endTransmission();
/*END Disable Trigger Mode/enable Bypass Mode*/
/*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*/
至於即使在沖擊后仍保持不變的值,我在僅讀取 output FIFO [0] 后重置觸發模式,當有 10 個 FIFO 收集數據時,正如我在寄存器 0x38(樣本 = 10)中配置的那樣。 因此,沖擊值存儲在 FIFO 的后期,而不是 FIFO [0]。 沖擊事件后讀取 FIFO 超過 10 次,然后重置觸發模式解決了問題。
樣本輸出(XYZ,g):
0.000 0.000 0.196
-0.490 0.098 0.000
0.098 -0.392 0.980
Shock Occured
FIFO STATUS REG: A0
ACT STATUS SHOCK REG: 1
INT_SOURCE: C3
0.490 -0.098 2.156
0.490 -0.098 2.156
0.392 0.098 1.960
0.392 0.294 2.254
0.294 0.098 1.960
-0.784 -0.882 1.470
-0.686 -0.980 1.274
10.976 13.524 59.290
27.342 17.934 36.358
-13.034 -6.566 -1.666
-0.098 0.098 1.078
0.000 0.294 0.686
0.098 0.098 1.470
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