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SPI : why my function works, but not the PICC function

 
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spilz



Joined: 30 Jan 2012
Posts: 220

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SPI : why my function works, but not the PICC function
PostPosted: Tue Oct 25, 2016 11:26 am     Reply with quote
hello,

I'm trying to use the CCS's SPI functions but it does not work, and with "my" SPI functions it works well ...

I guess I misunderstand Something but I don't know what ...

I'm using 16F690 with RFM69 module in SPI :

My code with "my" function :
Code:
#define CLOCK_MHZ    20
#define QUARTZ_MHZ   20

#include <16F690.h>

#device ADC=8
#FUSES NOWDT,PROTECT,BROWNOUT,NOMCLR,NOCPD,NOPUT   
#FUSES HS                       //High speed Osc (> 4mhz for PCM/PCH) (>10mhz for PCD)
#use delay(crystal=CLOCK_MHZ MHz)

#use rs232(baud=9600,parity=N,xmit=PIN_A0,rcv=PIN_A1,bits=8,restart_wdt,errors,TIMEOUT = 100,stream = RS232_PICKIT2)
#use rs232(baud=9600,parity=N,xmit=PIN_B7,rcv=PIN_B5,bits=8,errors,TIMEOUT = 100,STREAM = RS232_UART)

#define RFM69_MISO_PIN  PIN_B4
#define RFM69_MOSI_PIN  PIN_C7
#define RFM69_CLK_PIN   PIN_B6
#define RFM69_CS_PIN    PIN_C2
#define RFM69_RST_PIN   PIN_C6

#define RFM69_Select    output_low(RFM69_CS_PIN)
#define RFM69_UnSelect  output_high(RFM69_CS_PIN)

///////////////////////////////////////////////////////////
//Name:     SPICmd8bit
//Function: SPI Write one byte
//Input:    WrPara
//Output:   none
//note:     use for burst mode
///////////////////////////////////////////////////////////
void SPICmd8bit(int WrPara){
   byte bitcnt = 0;
   
   RFM69_Select;
   output_low(RFM69_CLK_PIN);
   
   for(bitcnt=8; bitcnt!=0; bitcnt--){
      output_low(RFM69_CLK_PIN);
     
      if(WrPara&0x80)
         output_high(RFM69_MOSI_PIN);// SDI = 1;
      else
         output_low(RFM69_MOSI_PIN);// SDI = 0;
         
      output_high(RFM69_CLK_PIN);
      WrPara <<= 1;
   }
   output_low(RFM69_CLK_PIN);
   output_high(RFM69_MOSI_PIN);// SDI = 1;
}

///////////////////////////////////////////////////////////
//Name:     SPIRead8bit
//Function: SPI Read one byte
//Input:    None
//Output:   result byte
//Note:     use for burst mode
///////////////////////////////////////////////////////////
int SPIRead8bit(void){
   byte RdPara = 0;
   byte bitcnt = 0;

   RFM69_Select;
   output_high(RFM69_MOSI_PIN);// SDI  = 1;    //Read one byte data from FIFO, MOSI hold to High
   
   for(bitcnt=8; bitcnt!=0; bitcnt--){
      output_low(RFM69_CLK_PIN);
      RdPara <<= 1;
      output_high(RFM69_CLK_PIN);
      if(input(RFM69_MISO_PIN))
         RdPara |= 0x01;
      else  //Codi per realitzar un retard del nombre especificat de cycles
         delay_cycles(1);//d'instruccio (1-255). Un cicle d'instrucció és igual
            //a quatre cicles de l'oscil·lador.
            //OSC16MHz --> (1*4)/16 = 0.25uS
   }
   
   output_low(RFM69_CLK_PIN);
   return(RdPara);
}

void main()
{
   int value = 0;
   
   setup_adc_ports(NO_ANALOGS|VSS_VDD);
   setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);       
   setup_wdt(WDT_OFF);
   disable_interrupts(GLOBAL);
   
   fprintf(RS232_PICKIT2,"16F690 RFM69\r\n");
   
   output_low(RFM69_RST_PIN);
   delay_ms(10);
   
   fprintf(RS232_PICKIT2,"SPI ");
   
   SPICmd8bit(0x2F|0x80);
   SPICmd8bit(0xAA);
   RFM69_UnSelect;
   
   delay_ms(10);
   
   SPICmd8bit(0x2F);                                         //Send address first
   value = SPIRead8bit();   
   RFM69_UnSelect;
   
   if(value == 0xAA)
   fprintf(RS232_PICKIT2,"OK\r\n");
   else
   fprintf(RS232_PICKIT2,"ERROR\r\n");
   
}


It works well,

but when I try this :
Code:
#define CLOCK_MHZ    20
#define QUARTZ_MHZ   20

#include <16F690.h>

#device ADC=8
#FUSES NOWDT,PROTECT,BROWNOUT,NOMCLR,NOCPD,NOPUT   
#FUSES HS                       //High speed Osc (> 4mhz for PCM/PCH) (>10mhz for PCD)
#use delay(crystal=CLOCK_MHZ MHz)

#use rs232(baud=9600,parity=N,xmit=PIN_A0,rcv=PIN_A1,bits=8,restart_wdt,errors,TIMEOUT = 100,stream = RS232_PICKIT2)
#use rs232(baud=9600,parity=N,xmit=PIN_B7,rcv=PIN_B5,bits=8,errors,TIMEOUT = 100,STREAM = RS232_UART)

#use spi (MASTER, DO=PIN_C7, DI=PIN_B4, CLK=PIN_B6, MODE=0, BITS=8, baud=115200)

#define RFM69_MISO_PIN  PIN_B4
#define RFM69_MOSI_PIN  PIN_C7
#define RFM69_CLK_PIN   PIN_B6
#define RFM69_CS_PIN    PIN_C2
#define RFM69_RST_PIN   PIN_C6

#define RFM69_Select    output_low(RFM69_CS_PIN)
#define RFM69_UnSelect  output_high(RFM69_CS_PIN)

void main()
{
   int value = 0;
   
   setup_adc_ports(NO_ANALOGS|VSS_VDD);
   setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);       
   setup_wdt(WDT_OFF);
   disable_interrupts(GLOBAL);
   
   fprintf(RS232_PICKIT2,"16F690 RFM69\r\n");
   
   output_low(RFM69_RST_PIN);
   delay_ms(10);
   
   fprintf(RS232_PICKIT2,"SPI ");
   
   spi_xfer(0x2F|0x80);
   spi_xfer(0xAA);
   RFM69_UnSelect;
   
   delay_ms(10);
   
   spi_xfer(0x2F);                                         //Send address first
   value = spi_xfer(0);   
   RFM69_UnSelect;
   
   if(value == 0xAA)
   fprintf(RS232_PICKIT2,"OK\r\n");
   else
   fprintf(RS232_PICKIT2,"ERROR\r\n");
   
}


it does not work ...

someone know why ?
What I miss understand ?

Thanks for your help

regards
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

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PostPosted: Tue Oct 25, 2016 11:41 am     Reply with quote
You are forgetting to select the chip....

Your code has the select line inside the routines. The CCS code does not. You are deselecting the chip after the transactions, but not selecting it before.....
spilz



Joined: 30 Jan 2012
Posts: 220

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PostPosted: Tue Oct 25, 2016 11:56 am     Reply with quote
that works Smile
really stupid error ^^

and what about using ENABLE in SPI ?

Code:
#use spi (MASTER, SPI1, MODE=0, BITS=8,ENABLE=PIN_C2,ENABLE_ACTIVE=0, baud=115200)


why it does not work ?

regards
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

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PostPosted: Tue Oct 25, 2016 12:50 pm     Reply with quote
Potentially yes.
You need to set the line high at the start of the code, and may need to add a delay between the enable and clocking (enable_delay in the #use).
spilz



Joined: 30 Jan 2012
Posts: 220

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PostPosted: Tue Oct 25, 2016 1:54 pm     Reply with quote
Enable_delay is not available for hardware SPI
But all other works fine

Thanks for your help
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

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PostPosted: Wed Oct 26, 2016 1:32 am     Reply with quote
The reason the hardware CS won't work for you is not the delay, but the way the chip expects the select to work. It wants it to stay low for the whole transaction. The ENABLE when using the CCS library operates on a per byte basis. It's designed for chips which use this (a byte enable), to ensure byte alignment, not to operate the CS. Assumes it you need a CS, you will be operating it 'manually' (in code).... Smile
spilz



Joined: 30 Jan 2012
Posts: 220

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PostPosted: Wed Oct 26, 2016 1:36 am     Reply with quote
OIC

I understand now, I'm going to do it 'manually'

thanks Smile
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