topic Re: SPI0 Freedom Board kl25z in Kinetis Microcontrollers

SPI0 Freedom Board kl25z

asdasdaram — Wed, 04 Sep 2013 09:37:29 GMT

Hello, does someone have used SPI0 Master Mode of KL25z Board without Processor Expert and could post some code pls

Re: SPI0 Freedom Board kl25z

martynhunt — Wed, 04 Sep 2013 14:42:42 GMT

Hi,

Here is a basic SPI0 Master send example.


#include "common.h"

void spi_init(void);
void spi_send(char spiMsg);


int main(void)
{

  char ch;

  spi_init();   //Init SPI0

  while(1)
 {
   ch = in_char();  //Read char from terminal
   spi_send(ch);    //Send char over SPI
   out_char(ch);    //Echo char to terminal
   
  }

}

void spi_init(void)
{
 SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK;      //Turn on clock to D module
 SIM_SCGC4 |= SIM_SCGC4_SPI0_MASK;       //Enable SPI0 clock

  PORTD_PCR0 = PORT_PCR_MUX(0x2);    //Set PTD0 to mux 2 [SPI0_PCS0]
  PORTD_PCR1 = PORT_PCR_MUX(0x2);    //Set PTD1 to mux 2 [SPI0_SCK]
  PORTD_PCR2 = PORT_PCR_MUX(0x2);    //Set PTD2 to mux 2 [SPI0_MOSI]
  PORTD_PCR3 = PORT_PCR_MUX(0x2);    //Set PTD3 to mux 2 [SPIO_MISO]

  SPI0_C1 = SPI_C1_MSTR_MASK | SPI_C1_SSOE_MASK;   //Set SPI0 to Master & SS pin to auto SS
  
  SPI0_C2 = SPI_C2_MODFEN_MASK;   //Master SS pin acts as slave select output 
  
  SPI0_BR = (SPI_BR_SPPR(0x02) | SPI_BR_SPR(0x08));     //Set baud rate prescale divisor to 3 & set baud rate divisor to 64 for baud rate of 15625 hz
  
  SPI0_C1 |= SPI_C1_SPE_MASK;    //Enable SPI0

}

void spi_send(char spiMsg)
{

  while(!(SPI_S_SPTEF_MASK & SPI0_S))
  {    
    asm("nop");  //While buffer is not empty do nothing
  }
    
  SPI0_D = spiMsg;    //Write char to SPI

}

Best regards,

Martyn

Re: SPI0 Freedom Board kl25z

emmanuelballest — Wed, 04 Sep 2013 15:09:15 GMT

Hi asdasd

If you need more information about SPI you check this link http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=FRDM-KL25Z&fpsp=1&tab=Design_Tools_Tab and download KL25_SC.

I hope this helps.

Re: SPI0 Freedom Board kl25z

asdasdaram — Wed, 04 Sep 2013 16:10:49 GMT

thx very much that works. in the twr_spi_demo there is also an initialisation of spi.

Re: SPI0 Freedom Board kl25z

asdasdaram — Thu, 05 Sep 2013 06:36:17 GMT

Its funny, after i initialise the SPI0 so the Blue LED is on. WHY?^^ BUT THE SPI WORKS

Re: SPI0 Freedom Board kl25z

emmanuelballest — Thu, 05 Sep 2013 14:50:47 GMT

The Blue LED pin is the same as the SPI0 in the port D this pin is PTD13 remember that is multiplexed.

Re: SPI0 Freedom Board kl25z

asdasdaram — Thu, 05 Sep 2013 17:20:05 GMT

Oh yes of course didnt think about it. But Now i have the next Problem. When i send for example an 0x01 Hex Number to the SPI Port in a while(1) loop i can see the Bit on the Oscilloscope.

But if i try to send 0xFF i while(1) loop so there is nothing. Its Maybe Because the Data collides??. Then I tried to Send some Data to my LCD to turn it on. the lcd expects 16 bits. And when I send the following: so i dont see 00000110 and 00000001 on the Oscilloscope its seems to be wrong sometimes it matches but the most time its wrong.

void display_on (void)

{

FGPIOE_PCOR= (1UL<<1) // Pin LOW for Write Command to SPI

spi_send(0x06); // Command for LCD Register

FGPIOE_PSOR= (1UL<<1) // Pin HIGH for Write Command to SPI

spi_send(0x01); // Data LCD

}

But, when i do SOFTWARE SPI the Display works and the bits are right on the Oscilloskope too

void Write_command(unsigned char Data)

{

unsigned char i;

CS_OFF; // Chip Select LOW

DC_OFF; // Pin LOW for Write Command to SPI

for (i=0; i<8; i++)

{

SCLK_OFF; // SCLK LOW

FGPIOC_PDOR=(Data&0x80)>>7; // MSB FIRST

Data = Data << 1;

SCLK_ON; / SCLK HIGH

}

DC_ON; // Pin LOW for Write Command to SPI

CS_ON; // Chip Select HIGH

}

void Write_data(unsigned char Data)

{

unsigned char i;

CS_OFF; // Chip Select LOW

DC_ON; // Pin HIGH for Write Command to SPI

for (i=0; i<8; i++)

{

SCLK_OFF; // SCLK LOW

FGPIOC_PDOR=(Data&0x80)>>7; // MSB FIRST

Data = Data << 1;

SCLK_ON; / SCLK HIGH

}

DC_ON; // PinHIGH for Write Command to SPI

CS_ON; // Chip Select HIGH

}

if i write to display now it works and i see the right Bits on the oscilloscope

int main(void)

{

Write_command(0x06) // Command to LCD

Write_data(0x01); // Data LCD ON

}

Re: SPI0 Freedom Board kl25z

martynhunt — Thu, 05 Sep 2013 22:19:00 GMT

Hi,

You might not be seeing any change in the MOSI line when writing 0xFF because it is high for the duration of the transfer. Could you post screen shots from your oscilloscope, please? Also, what type of LCD controller are you using? And, could you post a link to the datasheet?

Thank you,

Martyn

Re: SPI0 Freedom Board kl25z

asdasdaram — Fri, 06 Sep 2013 09:18:15 GMT

I can do the Screenshots Monday, The Controller is the SEPS525 the LCD is DD-160128FC-1A, http://www.techdesign.be/shop/datasheets/SEPS525[1].pdf , http://www.farnell.com/datasheets/302911.pdf

I initialise the SPI0 with CPHA=1 and CPOL=1 and i toggle the Chip Select like so

FGPIOE_PCOR= (1UL<<4) // Chip Select low

FGPIOE_PCOR= (1UL<<1) // Pin LOW for Write Command to SPI (RS PIN)

spi_send(0x06); // Command for LCD Register

FGPIOE_PSOR= (1UL<<1) // Pin HIGH for Write DATA to SPI (RS PIN)

FGPIOE_PSOR= (1UL<<4) // Chip Select HIGH

FGPIOE_PCOR= (1UL<<4) // Chip Select low

FGPIOE_PSOR= (1UL<<1) // Pin HIGH for Write DATA to SPI (RS PIN)

spi_send(0x01); // Data LCD

FGPIOE_PSOR= (1UL<<1) // Pin HIGH for Write DATA to SPI (RS PIN)

FGPIOE_PSOR= (1UL<<4) // Chip Select HIGH

I use the Pins PTD1 for SCK and PTD2 for MOSI. MISO is unused and i set SSOE and MODFEN=0, so Chip Select is unused too.

I also found a Lib for Arduino to handle the SEPS525 with SPI it look the same.

Thanks for help

Re: SPI0 Freedom Board kl25z

martynhunt — Fri, 06 Sep 2013 17:29:58 GMT

Hi,

I ran similar code with a SPI baud rate of 1MHz, and I saw the CS & RS lines toggling LOW then HIGH before the data had started shifting out of the SPI module. The code returns from the spi_send function before the data has finished sending; therefore, the CS line is set high too early. I'm looking into the best way to solve this issue.

Best regards,

Martyn

Re: Re: SPI0 Freedom Board kl25z

martynhunt — Fri, 06 Sep 2013 19:26:39 GMT

This should fix the CS & RS line toggling issue:

void spi_send(char spiMsg)  
{  
  volatile int i;
  FGPIOD_PCOR |= (1 << 0);  //Set SS low
  
  while(!(SPI_S_SPTEF_MASK & SPI0_S))  
  {      
    asm("nop");        //While buffer is not empty do nothing  
  }  
      
  SPI0_D = spiMsg;     //Write char to SPI   

  while(!(SPI_S_SPTEF_MASK & SPI0_S))  
  {      
    asm("nop");        //While buffer is not empty do nothing  
  }
  
  for(i = 0; i < 40; i++){}  //Wait for SPI to finish...adjust for baud rate


  FGPIOD_PSOR |= (1 << 0);   //Set SS high
}

I'm working on something nicer.

Best regards,

Martyn

Re: Re: SPI0 Freedom Board kl25z

asdasdaram — Fri, 06 Sep 2013 19:48:41 GMT

OK i will try it on monday with an oscilloskope. How about an interrupt request after SPTEF=1

BTW do you use KEIL? asm("nop"); The KEIL Compiler does not know this.

Re: SPI0 Freedom Board kl25z

martynhunt — Fri, 06 Sep 2013 22:49:59 GMT

I'm using IAR, so replace asm("nop"); with __nop();

Re: SPI0 Freedom Board kl25z

asdasdaram — Sat, 07 Sep 2013 13:42:48 GMT

I used your actual spi_send function and make shots with the oscilloscope when i sending

while(1)

{

spi_send(0x01);

spi_send(0x06);

}

It looks right i think. How about Chip Select its ok too !?

Re: SPI0 Freedom Board kl25z

martynhunt — Mon, 09 Sep 2013 13:56:29 GMT

HI,

It looks alright to me. The Saleae is getting valid data, which is good. Just to clarify, you attached pictures of SCK & MOSI for 0x01, SCK & MOSI for 0x06, SCK & CS, and the logic analyzer MOSI, SCK, & CS, correct? Is the LCD working?

Best regards,

Martyn

Re: SPI0 Freedom Board kl25z

asdasdaram — Mon, 09 Sep 2013 18:11:28 GMT

Hey yes right SCK & MOSI for 0x01, SCK & MOSI for 0x06, SCK & CS, and the logic analyzer MOSI, SCK, & CS. Today i got the LCD running :smileyhappy: very nice. You helped me a lot, thank you :smileyhappy:. One question, Why there is a logic HIGH on the MOSI WHEN SCLK is Idle.

Re: SPI0 Freedom Board kl25z

martynhunt — Mon, 09 Sep 2013 18:37:40 GMT

Hi,

Glad to hear everything works! Happy to help.

The MOSI line's idle state is high for this SPI module. Therefore, whenever it the SCK is idle (high or low) the MOSI line will idle high.

Best regards,

Martyn

Re: SPI0 Freedom Board kl25z

asdasdaram — Wed, 11 Sep 2013 09:54:28 GMT

Hi again, i try to use ADC on kl25z but cant get it work, maybe u used it already and it works? I want to control the V-Bat and make a bargraph on the LCD. There are an example for IAR "vlpr_lls_adc.c" but cant get it run for KEIL

Re: SPI0 Freedom Board kl25z

perharaldhelges — Tue, 06 May 2014 12:11:13 GMT

Hello Martyn Hunt. I`ve been studying this tread to make my spi work. The toggeling issue was not ficed by your code. I also have the problem of the cs going high and therebye resetting the register. How to solve this ?

Re: SPI0 Freedom Board kl25z

martynhunt — Tue, 06 May 2014 14:58:28 GMT

Hi,

I'd be happy to help you fix this issue you are seeing.

Would it be possible for you to share your code? Which Kinetis device are you developing on?

Also, what device is the slave in this SPI configuration?

Best regards,

Martyn