topic Re: SPI example code for loop back is not working for TRK-KE64 board in Kinetis Microcontrollers

SPI example code for loop back is not working for TRK-KE64 board

punithb — Tue, 29 Sep 2015 07:30:05 GMT

void serial_flash_init(void)

{

SIM->SCGC |= SIM_SCGC_SPI0_MASK;

CONFIG_PIN_AS_GPIO(PTB,SPI0_CS,OUTPUT);

CONFIG_PIN_AS_GPIO(PTB,SPI0_MOSI,OUTPUT);

CONFIG_PIN_AS_GPIO(PTB,SPI0_SCK,OUTPUT);

CONFIG_PIN_AS_GPIO(PTB,SPI0_MISO,INPUT);

ENABLE_INPUT(PTB,SPI0_MISO);

CONFIG_PIN_AS_GPIO(PTB,SPI0_CS,OUTPUT);

OUTPUT_SET(PTB,SPI0_CS);

SPI0_C1 |= SPI_C1_MSTR_MASK; // SPI0 master mode

SPI0_BR = 0x00;//0x43; //SPPR = 4, SPR = 3, bps div = (SPPR+1)*2^(SPR+1) = 80, baudrate= 24Mhz/80=300khz

SPI0_C1 |= SPI_C1_SSOE_MASK;

SPI0_C1 &= (~SPI_C1_CPHA_MASK); // clock polarity

SPI0_C1 &= (~SPI_C1_CPOL_MASK); //clock phase

SPI0_C1 &= (~SPI_C1_LSBFE_MASK); // LSB:most significant

SPI0_C1 &= (~SPI_C1_SPIE_MASK); //Disable RX interrrupt

SPI0_C1 &= (~SPI_C1_SPTIE_MASK); //Disable the transmit interrupt

SPI0_C2 |= SPI_C2_MODFEN_MASK;

SPI0_C1 |= SPI_C1_SPE_MASK; // enable SPI module

}

uint8_t hal_spi_transfer_one_byte(uint8_t v)

{

int dummy =0;

char buff=0;

while ((SPI0_S & SPI_S_SPTEF_MASK) == 0) // wait for transmit buffer empty

{

dummy++;

}

dummy = SPI0_S;

SPI0_D = v; // send one byte to transmit buffer

while ((SPI0_S & SPI_S_SPRF_MASK) == 0); // wait ready buffer full

buff = SPI0_D; // read one received byte

return buff; // return the received byte

}

void hal_spi_transfer_start()

{

OUTPUT_CLEAR(PTB,SPI0_CS);

}

void hal_spi_transfer_stop()

{

OUTPUT_SET(PTB,SPI0_CS);

}

int main()

{

serial_flash_init();

for(;;)

{

hal_spi_transfer_start();

buff=hal_spi_transfer_one_byte(0xAA);

if(buff==0xAA || buff==0x55)

{

LED3_ON;

}

hal_spi_transfer_stop();

LED2_ON;

}

But LED3 is not on, i probed clock pin and mosi and miso , all are ok .

Could any one tell what may be the issue?.

Re: SPI example code for loop back is not working for TRK-KE64 board

punithb — Tue, 29 Sep 2015 11:29:06 GMT

Could any one tell the sampling code for SPI, i want to test loop back method.

Here what i did.

#define SPI0_SCK PTE0

#define SPI0_MOSI PTE1

#define SPI0_MISO PTE2

#define SPI0_CS PTE3

void serial_flash_init(void)

{

SIM->PINSEL|=SIM_SCGC_SPI0_MASK;

SIM->SCGC |= SIM_SCGC_SPI0_MASK;

CONFIG_PIN_AS_GPIO(PTE,SPI0_CS,OUTPUT);

CONFIG_PIN_AS_GPIO(PTE,SPI0_MOSI,OUTPUT);

CONFIG_PIN_AS_GPIO(PTE,SPI0_SCK,OUTPUT);

CONFIG_PIN_AS_GPIO(PTE,SPI0_MISO,INPUT);

ENABLE_INPUT(PTE,SPI0_MISO);

//ENABLE_PULLUP(PTE,SPI0_MISO);

CONFIG_PIN_AS_GPIO(PTE,SPI0_CS,OUTPUT);

OUTPUT_SET(PTE,SPI0_CS);

SPI0_C1 = 0x54;

SPI0_C2 =0x80;

SPI0_BR = 0x00;

}

uint8_t hal_spi_transfer_one_byte(uint8_t v)

{

int dummy =0;

char buff=0;

while ((SPI0_S & SPI_S_SPTEF_MASK) == 0) // wait for transmit buffer empty

{

dummy++;

}

dummy = SPI0_S;

SPI0_D =v; // send one byte to transmit buffer

while ((SPI0_S & SPI_S_SPRF_MASK) == 0); // wait ready buffer full

buff = SPI0_D; // read one received byte

return buff; // return the received byte

}

void hal_spi_transfer_start()

{

OUTPUT_CLEAR(PTE,SPI0_CS);

}

void hal_spi_transfer_stop()

{

OUTPUT_SET(PTE,SPI0_CS);

}

int main()

{

uint8_t buff;

Clk_Init(); /* Configure clocks to run at 20 Mhz, TRK board does not include XTAL */

GPIO_Init(); /* Configure button pins as inputs and LED pins as outputs */

serial_flash_init();

while(1)

{

hal_spi_transfer_start();

buff=hal_spi_transfer_one_byte(0xAA);

if(buff==0xAA || buff==0x55)

{

LED3_ON;

}

if(buff==0xFF)

{

LED2_ON;

}

if( buff==0x00)

{

LED1_ON;

}

hal_spi_transfer_stop();

}

But i am not able to write 0xAA in to SPIO_D register , it is taking only 0xFF. i checked debug also , it is always updating with 0xFF instead of 0xAA.

Could any one tell me what is wrong in my code. I dont want to use PE generated code. i need to know what is problem in my code.

Kindly let me know the problem.

Regards

punith

Re: SPI example code for loop back is not working for TRK-KE64 board

punithb — Wed, 30 Sep 2015 14:47:03 GMT

Can any one please address this issue?.

Re: SPI example code for loop back is not working for TRK-KE64 board

david_diaz — Mon, 19 Oct 2015 21:55:42 GMT

Hello,

You can find attached to this response a simple SPI application (SPI.c/h).

The project is intended for the KEA128.

Please refer to chapter 29 from the Reference manual at:

http://www.freescale.com/files/microcontrollers/doc/ref_manual/KEA64RM.pdf

Please let me know if this material is useful for you.

Have an excellent day.

David