Stm32 ADXL345 Sensor

Acceleration Sensitivity Axis
The corresponding output voltage increases when accelerating along the sensitive axis

Register Mappings

Register Definition
0x31-data_format

Self_test bit: Set to 1, self-Test force applied to the sensor, resulting in output data conversion. A value of 0 o'clock disables self-test force
SPI bit: value 1, set device to 3-wire SPI mode, value 0, set to 4-wire SPI mode
Int_invert bit: value 0, set interrupt to High active, value 1, set to low active
Full_res bit: Set to 1, the device is full-resolution mode, and the output resolution increases with a scale factor of 4 MG/LSB as the range bit sets the G range. The Full_res bit is set to 0 o'clock, the device is a 10-bit mode, and the range bit determines the maximum G range and scale factor
Align bit: Set to 1, select left-aligned (MSB) mode, set to 0, select right-justified mode, and have symbol extension function
Range bit: Set G range

0x2c-bw_rate

Low_power bit: Set to 0, select Normal operation, set to 1, select low power operation, the noise increases at this time
Rate bit: Select the device bandwidth and output data rate. The default value is 0x0a, and the output data rate is converted to 100Hz

0x2d-power_ctl

Link bit: The link bit for the active and QUIESCE functions is set to 1, and the deferred activity function starts until it detects a standstill. When activity is detected, standstill detection starts and activity detection stops. The bit serial link activity and Quiesce function. This bit is set to 0 o'clock, and the QUIESCE function and the active function are simultaneously
Auto_sleep bit: Set link bit, Auto_sleep bit set to 1, auto sleep function enable
Measurement bit: Set the measuring bit to 0, put the device in standby mode, set to 1, put in measurement mode
Sleep bit: The sleep bit is set to 0, the device is placed in normal operation mode, set to 1, put into sleep mode
Wake-up bit: control read frequency in sleep mode

0x2e-int_enable

Set the bit value to 1, enable the corresponding function, generate interrupts, set to 0 o'clock, prevent these features from interrupting

Registers 0x1e, 0x1F, 0X20-OFSX, Ofsy, Ofsz. Provide user set offset adjustment

Registers 0x32 to 0x37-datax0, DATAX1, DATAY0, DATAY1, DATAZ0, and DATAZ1. Save output data for each axis

Example

#define DEVICE_ID 0x00//device ID #define THRESH_TAP 0X1D #define OFSX 0X1E #define OFSY 0X1F #define OFSZ 0X20 #define DUR 0X21 #define Latent 0X22 #define Window 0X23 #def INE thresh_ack 0X24 #define THRESH_INACT 0X25 #define TIME_INACT 0X26 #define ACT_INACT_CTL 0X27 #def INE thresh_ff 0X28 #define TIME_FF 0X29 #define Tap_axes 0X2A #define Act_tap_status 0X2B #defin E bw_rate 0X2C #define POWER_CTL 0X2D #define Int_enable 0x2e #define INT_MAP 0X2F #define INT_SOURC E 0X30 #define DATA_FORMAT 0X31 #define DATA_X0 0X32 #define DATA_X1 0X33 #define DATA_Y0 0x34 #define DA Ta_y1 0X35 #define DATA_Z0 0X36 #define DATA_Z1 0X37 #define FIFO_CTL 0X38 #define Fifo_status 0X39 #d Efine Adxl_read 0X3B//Read instruction #define Adxl_write 0X3A//write instruction typedef enum {x,//x axis angle Y,//with y axis angle z//with Z axis

Angle of}dir_t; void ADXL345_write (U8 addr, U8 data) {I2c_start ();
    I2c_send_byte (Adxl_write);
    I2c_wait_ack ();
    I2c_send_byte (addr);
    I2c_wait_ack ();
    I2c_send_byte (data);
    I2c_wait_ack ();  

    I2c_stop ();
Delay_ms (10);

    } U8 Adxl345_read (U8 addr) {U8 d = 0;    
    I2c_start ();
    I2c_send_byte (Adxl_write);
    I2c_wait_ack ();
    I2c_send_byte (addr);
    I2c_wait_ack ();    
    I2c_start ();
    I2c_send_byte (Adxl_read);
    I2c_wait_ack ();
    D = I2c_recv_byte ();
    I2c_ack (1);

    I2c_stop ();   
return D;

    } void Adxl345_init () {U8 D;

    I2c_init ();

    D = Adxl345_read (device_id);

    printf ("Adxl345_read%d\n", D); if (d = = 0xe5) {adxl345_write (Data_format, 0x2B);//Interrupt low active, 13-bit full resolution mode, 16g range Adxl345_write (power_ctl, 0 X28); Link Enable, Measurement mode Adxl345_write (int_enable, 0x00);
        Do not use interrupt Adxl345_write (OFSX, 0x00);
        Adxl345_write (Ofsy, 0x00);
    Adxl345_write (Ofsz, 0x00); }} void Adxl345_read_xyz (short *x, ShoRT *y, Short *z) {U8 i = 0;

    U16 Buf[6] = {0};    
    I2c_start ();
    I2c_send_byte (Adxl_write);
    I2c_wait_ack (); I2c_send_byte (0x32);
    Data first address i2c_wait_ack ();    
    I2c_start ();
    I2c_send_byte (Adxl_read);

    I2c_wait_ack (); for (i = 0; i < 6; i++)//A total of 6 {buf[i] = I2c_recv_byte ();//printf ("i2c_recv_byte [%d]%d\r\n", I, BU
        F[i]);
        if (i = = 5) {i2c_ack (1);
        } else {i2c_ack (0);

    }} i2c_stop ();         
    *x = (short) ((buf[1]<<8) + buf[0]);         
    *y = (short) ((buf[3]<<8) + buf[2]);
*z = (short) ((buf[5]<<8) + buf[4]);
    } void Adxl345_read_times (short *x, short *y, short *z, U8 times) {U8 i = 0;

    Short TX, Ty, TZ;

    *x = *y = *z = 0;

        for (i = 0; i < time; i++)//Read times {adxl345_read_xyz (&tx, &ty, &tz);
        *x + = TX;
        *y + = Ty;       

        *z + = TZ; Delay_ms (5); } *x/= times;
    Find average *y/= times;    
*z/= times;
    } short Adxl345_get_result (float x, float y, float z, U8 dir)//calculate angle {float T;

    float Res;
            Switch (dir) {Case x:t = x/sqrt (y*y + z*z); res = Atan (t);
        Find the arc break;
            Case y:t = y/sqrt (x*x + z*z);
            res = Atan (t);
        Break
            Case z:t = sqrt (x*x + y*y)/Z;
            res = Atan (t);
        Break
    Default:break; } return (res * 180/3.14);
    Find the angle} void Adxl345_main () {short x, y, Z;

    Short Rx, Ry, RZ; Adxl345_read_times (&x, &y, &z, 10);
    Read the x, Y, z-direction acceleration values printf ("×%d\n", x);
    printf ("y%d\n", y);

    printf ("Z%d\n", z);
    Rx = Adxl345_get_result (x, Y, z, x);
    ry = Adxl345_get_result (x, y, z, y);
    RZ = Adxl345_get_result (x, y, z, z);
    printf ("Rx%d\n", RX);
    printf ("Ry%d\n", ry);
printf ("RZ%d\n", RZ); }