MCP3204 SPI PROBLEM???

800 to BFF

That might be a problem with the SPI settings (clock phase and polarity). There are four possible combinations, which are also called SPI modes. Make sure you use the SPI mode that the ADC expects.

800 to BFF

That might be a problem with the SPI settings (clock phase and polarity). There are four possible combinations, which are also called SPI modes. Make sure you use the SPI mode that the ADC expects.

Firstly,
Thanks for your reply.
Yes can be.. But I don't know so much about spi comm.
If you explain much more to solve the problem I will be pleased for your help. I also written the program code in C below.

#include<at898252.h>
#include<stdio.h>

sbit ADC_CS = P3^4;
sbit ADC_CLK = P1^7;
sbit ADC_DO = P1^6;
sbit ADC_DI = P1^5;

void InitSerial(void);
void write_adc_byte(char data_byte);
unsigned int ReadADC(unsigned char channel);
void DelayMs(unsigned int count);

//---------------------------------------
// Main program
//---------------------------------------
void main(void)
{ InitSerial(); // Initialize serial port while(1) { putchar(0x0C); // clear Hyper terminal printf("Ch 0 : %03X\n\r",ReadADC(0)); printf("Ch 1 : %03X\n\r",ReadADC(1)); DelayMs(1000); // Delay about 100 mS }
}

//---------------------------------------
// Initialize serial port
//---------------------------------------
void InitSerial(void)
{ SCON = 0x52; // setup serial port control TMOD = 0x20; // hardware (9600 BAUD @11.05592MHZ) TH1 = 0xFD; // TH1 TR1 = 1; // Timer 1 on
}

//---------------------------------------
// read analog from ADC
// Single end mode(2 channel)
//---------------------------------------
unsigned int ReadADC(unsigned char channel)
{ unsigned char i,k; unsigned int AdcResult; // 12 bit

ADC_CS=0; // Active chip select k++; // Delay about 1 uS ADC_CLK=0; // make clock low first k++;k++; channel = channel? 0xF0 : 0xE0; k++;k++; // delay about 2 uS //--- write command 4 bit ---------- for(i=0; i< 4;i++) { ADC_DI = (channel & 0x80) != 0; channel<<=1; ADC_CLK=1; k++;k++; // delay about 2 uS ADC_CLK=0; }

k++;k++; // delay about 2 uS ADC_CLK=1; k++;k++; // delay about 2 uS ADC_CLK=0; k++;k++; // delay about 2 uS

//--- read ADC result 12 bit -------- AdcResult=0; for(i=0;i<12;i++) { ADC_CLK=1; k++;k++; // delay about 2 uS AdcResult<<=1; AdcResult=AdcResult | (ADC_DO & 0x01); ADC_CLK=0; k++;k++; // delay about 2 uS } ADC_CS=1; return(AdcResult);
}

//---------------------------------------
// Delay mS function
//---------------------------------------
void DelayMs(unsigned int count) { // mSec Delay 11.0592 Mhz unsigned int i; // Keil v7.5a while(count) { i = 115; while(i>0) i--; count--; }
}