Posted on February 11, 2014 at 22:11 Hi all,I'm trying to read data from a L3G4200D gyro through an SPI module of aPIC32MX460F.The following is the code I'm using:
void
Spi1STL3G4200DConfig(
void
) {
unsigned
int
configA, configB;
int
rData;
configA = SPI_MODE8_ON |
SPI_CKE_ON |
CLK_POL_ACTIVE_HIGH |
MASTER_ENABLE_ON |
SEC_PRESCAL_3_1 |
PRI_PRESCAL_4_1;
// 80/12 = 6.66Mhz
configB = SPI_ENABLE;
rData = SPI1BUF;
IFS0CLR = 0x03800000;
SPI1STATCLR = 0x40;
OpenSPI1(configA, configB);
//configuro i pin SPI1
mPORTDSetPinsDigitalOut(BIT_0 | BIT_9 | BIT_10);
mPORTCSetPinsDigitalIn(BIT_4);
//C4 input digitale
if
(STL3G4200D_SpiReadRegister(WHO_AM_I) != 0xD3)
// ALWAYS OK !
return
-1; DelayMs(200);
STL3G4200D_SpiWriteRegister(CTRL_REG1, 0b00001111);
STL3G4200D_SpiWriteRegister(CTRL_REG5, 0b00000010);
//low pass filtering
DelayMs(200);
STL3G4200D_SpiReadRegister(0x29);
// ALWAYS FAILS WITH CODE HANGING AT SECOND ''while (!SPI1STATbits.SPIRBF)''
}
int
STL3G4200D_SpiReadRegister(
char
address){
int
toRead;
address |= 0x80;
//stiamo leggendo....0xA9 dopo l'OR
CS1GYRO = 0;
// _RD9
SPI1BUF = address;
while
(!SPI1STATbits.SPIRBF);
toRead = SPI1BUF;
// ALWAYS 0xFF AFTER GYRO INIT
SPI1BUF = 0x00;
while
(!SPI1STATbits.SPIRBF);
// CODE HANGS HERE AFTER GYRO INIT
toRead = SPI1BUF;
CS1GYRO = 1;
return
toRead;
}
void
STL3G4200D_SpiWriteRegister(unsigned
int
address, unsigned
int
data) {
address &= 0x7F;
//vogliamo scrivere
CS1GYRO = 0;
SPI1BUF = address;
//SPI.transfer(address);
while
(!SPI1STATbits.SPIRBF);
SPI1BUF = data;
//SPI.transfer(data);
while
(!SPI1STATbits.SPIRBF);
CS1GYRO = 1;
}
The code always hangs after gyro initialization and after the successful reading ofdevice ID.I use the same code
(with different prescaler values according to therequested SPI clock rates) to read XYZ channels from accelerometerswithout any problem. Lastly I'm able to read data from the gyro using I2C communicationprotocol but I needperformance so I'd like to use SPI module.Thank's for your help.Raffaele
