我需要使用 Sparkfun 分线板ADXL345来检测我的电机系统何时停止振动。我也在使用 Sparkfun RedBoard（Arduino uno）。
我正在为此行为配置的事情：
- 启用 INACTIVITY 事件
- 将 INACTIVITY 事件路由到 INT 1（红板上的引脚 2）
- 立即引发 INACTIVITY 中断
- 为 INACTIVITY 设置低阈值（排除设置太高）
- INACTIVITY 考虑所有轴
- 清除中断数据寄存器
完成所有这些事情后，从摇动设备到放下设备，我没有收到任何中断。
//Add the SPI library so we can communicate with the ADXL345 sensor
#include <SPI.h>
//Assign the Chip Select signal to pin 10.
int CS=10;
//This is a list of some of the registers available on the ADXL345.
//To learn more about these and the rest of the registers on the ADXL345, read the datasheet!
char POWER_CTL = 0x2D; //Power Control Register
char DATA_FORMAT = 0x31;
char DATAX0 = 0x32; //X-Axis Data 0
char DATAX1 = 0x33; //X-Axis Data 1
char DATAY0 = 0x34; //Y-Axis Data 0
char DATAY1 = 0x35; //Y-Axis Data 1
char DATAZ0 = 0x36; //Z-Axis Data 0
char DATAZ1 = 0x37; //Z-Axis Data 1
char THRESH_ACT = 0x24; // Activity threshold
char THRESH_INACT = 0x38; // Inactivity threshold to 3g
char TIME_INACT = 0x26; // time before raising interrupt
char INT_ENABLE = 0x2E; // Enabling the interrupt lines
char INT_MAP = 0x2F;
char ACT_INACT_CTL = 0x27; // mask byte for controlling
char INT_SOURCE = 0x30;
//This buffer will hold values read from the ADXL345 registers.
char values[10];
//These variables will be used to hold the x,y and z axis accelerometer values.
int x,y,z;
void setup(){
//Initiate an SPI communication instance.
SPI.begin();
//Configure the SPI connection for the ADXL345.
SPI.setDataMode(SPI_MODE3);
//Create a serial connection to display the data on the terminal.
Serial.begin(9600);
//Set up the Chip Select pin to be an output from the Arduino.
pinMode(CS, OUTPUT);
//Before communication starts, the Chip Select pin needs to be set high.
digitalWrite(CS, HIGH);
// Create an interrupt that will trigger when inactivity is detected
attachInterrupt(0, interruptHandler, RISING);
//Put the ADXL345 into +/- 4G range by writing the value 0x01 to the DATA_FORMAT register.
writeRegister(DATA_FORMAT, 0x01);
//Put the ADXL345 into Measurement Mode by writing 0x08 to the POWER_CTL register.
writeRegister(POWER_CTL, 0x08); //Measurement mode
// Send the inactivity && activity to PIN 1
// 0xF7 && 0xEF
writeRegister(INT_MAP,0xF7 && 0xEF);
// Set the inactivity threshold to 3g (0x38)
// writeRegister(THRESH_INACT,0x38);
writeRegister(THRESH_INACT,1);
// Raise the inact interrupt immediately after going below threshold
writeRegister(TIME_INACT,0);
// Map INACT event (only) to PIN 1
writeRegister(ACT_INACT_CTL, 0x0F);
// Enab le inactivity to generate interrupts
writeRegister(INT_ENABLE, 0x08);
readRegister(INT_SOURCE, 1, values); // Clear the INT_SOURCE register
Serial.println("Waiting for interrupt!");
}
void interruptHandler(){
// readRegister(INT_SOURCE, 1, values); // Clear the INT_SOURCE register
Serial.println("something raise an interrupt!");
}
void loop(){
//Reading 6 bytes of data starting at register DATAX0 will retrieve the x,y and z acceleration values from the ADXL345.
//The results of the read operation will get stored to the values[] buffer.
readRegister(DATAX0, 6, values);
//The ADXL345 gives 10-bit acceleration values, but they are stored as bytes (8-bits). To get the full value, two bytes must be combined for each axis.
//The X value is stored in values[0] and values[1].
x = ((int)values[1]<<8)|(int)values[0];
//The Y value is stored in values[2] and values[3].
y = ((int)values[3]<<8)|(int)values[2];
//The Z value is stored in values[4] and values[5].
z = ((int)values[5]<<8)|(int)values[4];
//Print the results to the terminal.
Serial.print(x, DEC);
Serial.print(',');
Serial.print(y, DEC);
Serial.print(',');
Serial.println(z, DEC);
delay(500);
}
//This function will write a value to a register on the ADXL345.
//Parameters:
// char registerAddress - The register to write a value to
// char value - The value to be written to the specified register.
void writeRegister(char registerAddress, char value){
//Set Chip Select pin low to signal the beginning of an SPI packet.
digitalWrite(CS, LOW);
//Transfer the register address over SPI.
SPI.transfer(registerAddress);
//Transfer the desired register value over SPI.
SPI.transfer(value);
//Set the Chip Select pin high to signal the end of an SPI packet.
digitalWrite(CS, HIGH);
}
//This function will read a certain number of registers starting from a specified address and store their values in a buffer.
//Parameters:
// char registerAddress - The register addresse to start the read sequence from.
// int numBytes - The number of registers that should be read.
// char * values - A pointer to a buffer where the results of the operation should be stored.
void readRegister(char registerAddress, int numBytes, char * values){
//Since we're performing a read operation, the most significant bit of the register address should be set.
char address = 0x80 | registerAddress;
//If we're doing a multi-byte read, bit 6 needs to be set as well.
if(numBytes > 1)address = address | 0x40;
//Set the Chip select pin low to start an SPI packet.
digitalWrite(CS, LOW);
//Transfer the starting register address that needs to be read.
SPI.transfer(address);
//Continue to read registers until we've read the number specified, storing the results to the input buffer.
for(int i=0; i<numBytes; i++){
values[i] = SPI.transfer(0x00);
}
//Set the Chips Select pin high to end the SPI packet.
digitalWrite(CS, HIGH);
}