Lpc2000

Hi,

I don't know about ADS7808, but i have done some work with MAX1271
and ADS8344, i think it similar.
I think you  started sampling every time by writing 0x10 to SPI,
so you got always only the high byte of conversion.

Try it like this :

 SPI0_SPDR = 0x10; // assumed this statement starts the sampling 
 while(!(SPI0_SPSR & SPIF)){} //wait that transmit
 gyro_x = SPI0_SPDR; //save the 8 most significant bits
 gyro_x = (gyro_x << 8);
 SPI0_SPDR = 0x0;  // do not start sampling anymore
 while(!(SPI0_SPSR & SPIF)){} //wait that transmit  
 gyro_x += SPI0_SPDR;

regards 

Peter

--- In lpc2000@yahoogroups.com, dasbento@a... wrote:
> 
> Hello,
> 
> I'm using SPI to read data of ADS7807U. My problem is not get to read
> the last bit, i.e, bit0. How does the SCK work? 
> 
> Anybody already work with this and can I help me???
> 
> Thanks
>       Domingos
> 
> 
> IOCLR0 |= SSEL0; //select AD
> IOCLR0 |= AD_RC; //(R/C = 0)
> 
> delay(2); //wait 50ns
> 
> IOSET0 |= SSEL0;
> IOSET0 |= AD_RC;
> 
> while(!(IOPIN1 & busy_x)){} //wait for busy is 1
> 
> IOCLR0 |= SSEL0; //select AD
> 
> 
> for(i=0;i<2;i++){
> SPI0_SPDR = 0x10;
> 
> while(!(SPI0_SPSR & SPIF)){} //wait that transmit
> 
> if(i==0){
> gyro_x = SPI0_SPDR; //save the 8 most significant bits
> 
> gyro_x = (gyro_x << 8);
> }else{
> gyro_x += SPI0_SPDR;
> }
> }
> 
> IOSET0 |= SSEL0; //deselect AD
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