How do i use SPI communication on this broad?
Introduction:
https://learn.sparkfun.com/tutorials/9d … troduction
Schematic:
https://cdn.sparkfun.com/assets/learn_t … ematic.pdf
Datasheet(mpu9250):
https://cdn.sparkfun.com/assets/learn_t … REV1.0.pdf
I tried to connect it to my arduino broad(nano) to implement multiple slaves like adding accelerometer,etc.
I read imu m0 schematic and mpu9250 datasheet about their spi connection.
imu m0 schematic(mpu9250 part)
https://i.imgur.com/RDVGSOs.jpg
mpu9250 datasheet(p.20 SPI operation)
https://i.imgur.com/G8y88Nf.jpg
I connected cs to nano’s cs(pin10),sd0 to nano’s miso,sdi to nano’s mosi,sclk to nano’s sclk.
Well,NOT work at all haha.
I even can’t read the value of WHO_AM_I register.
i think maybe it’s besause i didn’t supply power,but imu m0 schematic indicate CS is connected to 3.3V,and also Vdd and Vddid.
And SDO had connected to gnd.
Don’t have confident to wire it…though i still do it but still no value.
I see many break out pin on it,but i can’t find example on internet.
Is it can’t use the SPI interface? or there is a solution for it
I’m just a student new to it.
So… help…
my code:
#include <SPI.h>
#define ACCEL_XOUT_H 0x3B
#define ACCEL_XOUT_L 0x3C
#define ACCEL_YOUT_H 0x3D
#define ACCEL_YOUT_L 0x3E
#define ACCEL_ZOUT_H 0x3F
#define ACCEL_ZOUT_L 0x40
#define WHO_AM_I 0x75
#define PWR_MGMT_1 0x6B
#define PWR_MGMT_2 0x6C
#define ASTC 0x0CH
#define ST_X_ACCEL 0x0D
#define ST_Y_ACCEL 0x0E
#define ST_Z_ACCEL 0x0F
const int chipSelectPin = 10;
int values[20],t[9];
double x, y, z;
void setup() {
Serial.begin(115200);
SPI.begin();
SPI.setClockDivider(SPI_CLOCK_DIV16);
SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
pinMode(chipSelectPin, OUTPUT);
writeRegister(PWR_MGMT_2, 0x00);
writeRegister(PWR_MGMT_1, 0x80);
digitalWrite(chipSelectPin, HIGH);
delay(100);
}
void loop() {
values[0] = readRegister(ACCEL_XOUT_H);
values[1] = readRegister(ACCEL_XOUT_L);
values[2] = readRegister(ACCEL_YOUT_H);
values[3] = readRegister(ACCEL_YOUT_L);
values[4] = readRegister(ACCEL_ZOUT_H);
values[5] = readRegister(ACCEL_ZOUT_L);
t[0]=readRegister(WHO_AM_I);
x= (values[0] << 8) + values[1];
y= (values[2] << 8) + values[3];
z= (values[4] << 8) + values[5];
Serial.print(x);
Serial.print(',');
Serial.print(y);
Serial.print(',');
Serial.print(z);
Serial.print(',');
Serial.print(t[0],HEX);
Serial.print('\n');
delay(5);
}
byte readRegister (byte thisRegister) {
byte inByte = 0 ;
digitalWrite(chipSelectPin, LOW);
SPI.transfer(thisRegister | 0x80);
inByte = SPI.transfer(0x00);
digitalWrite(chipSelectPin, HIGH);
return inByte;
}
void writeRegister (byte thisRegister, byte value) {
digitalWrite(chipSelectPin, LOW);
SPI.transfer(thisRegister);
SPI.transfer(value);
digitalWrite(chipSelectPin, HIGH);
}