Posted on June 22, 2017 at 15:50Hi, I'm new here and I am new at working on mems.
I have a LPCXpresso1549 evaluation board and a Steval-MKI172v1 mems that implements a lsm303agr chip.
I'm working on mbed platform and I need to read values from accelerometer but I tried a lot and cannot read anything.
I connect pins for SCL and SDA, 3V3 to the VDD pin, the GND, and two digital pins to the CS and CS_A (chip select on lsm303agr).
I don't know what address my lsm303 has and I can't understand what address I need to write on registers
:(
My code is:
&sharpinclude 'mbed.h'
&sharpdefine ACC 0x00
&sharpdefine CTRL_REG1_A 0x20
&sharpdefine CTRL_REG2_A 0x21
&sharpdefine CTRL_REG3_A 0x22
&sharpdefine CTRL_REG4_A 0x23
&sharpdefine CTRL_REG5_A 0x24
&sharpdefine OUT_X_L_A 0x28
&sharpdefine OUT_X_H_A 0x29
&sharpdefine OUT_Y_L_A 0x2A
&sharpdefine OUT_Y_H_A 0x2B
&sharpdefine OUT_Z_L_A 0x2C
&sharpdefine OUT_Z_H_A 0x2D
typedef struct Plane {
float x, y, z;
} Plane;
Plane a;
//Plane a_max;
//Plane a_min;
Serial pc(USBTX, USBRX); // tx, rx
I2C i2c(P0_23, P0_22);
DigitalOut chip_sel_a(P0_27);
DigitalOut chip_sel_m(P0_28);
void LSM303_write (int data, int reg_address) {
char out[2] = { reg_address, data };
i2c.write( ACC, out, 2 );
}
int main() {
//setup iniziale
chip_sel_a = 1;
chip_sel_m = 0;
LSM303_write(0x57, CTRL_REG1_A);
LSM303_write(0x81, CTRL_REG4_A);
LSM303_write(0x00, CTRL_REG2_A);
LSM303_write(0x00, CTRL_REG3_A);
LSM303_write(0x00, CTRL_REG5_A);
while(1) {
char data[1] = { OUT_X_L_A | (1<<7)}; //mette un 1 in testa all'indirizzo per fare read multipla
char out[6] = {0,0,0,0,0,0};
i2c.write( ACC, data,1);
i2c.read( ACC, out, 6);
a.x = short( (((short)out[1]) << 8) | out[0] );
a.y = short( (((short)out[3]) << 8) | out[2] );
a.z = short( (((short)out[5]) << 8) | out[4] );
pc.printf('asse x: %f\n', a.x);
pc.printf('asse y: %f\n', a.y);
pc.printf('asse z: %f\n\n', a.z);
wait(2);
}
}
Could someone help me?
:(
#sensor #steval-mki172v1 #lpc1549 #lpcxpresso #mems #lsm303agr
