MAX6954 SPI Help

[jayanthd]

I have written a SPI code for MAX6954 to drive 8 X 16 Segment displays but it is not working. I am testing it in both hardware and Proteus. In Proteus I sometimes see one of the display turn ON for a moment. I am posting my Code and attaching my mikroC PRO PIC + Proteus files. I feel it is an issue with timing that is causing it not to work. Please have a look at my code and tell me where I have gone wrong. If possible please test it on hardware and tell me what is the problem. I don't have an Oscilloscope.

Code: Select all

#define reg_noOp 0x00
#define reg_decodeMode 0x01
#define reg_globalIntensity 0x02
#define reg_scanLimit 0x03
#define reg_configuration 0x04
#define reg_displayTest 0x07
#define reg_digitType 0x0C

#define reg_intensity10 0x10
#define reg_intensity32 0x11
#define reg_intensity54 0x12
#define reg_intensity76 0x13
#define reg_intensity10a 0x14
#define reg_intensity32a 0x15
#define reg_intensity54a 0x16
#define reg_intensity76a 0x17

#define USE_GLOBAL 0x00
#define USE_DISCRETE 0x40
#define RUN 0x01
#define SHUTDOWN 0x00

#define reg_digit0 0x60
#define reg_digit1 0x61
#define reg_digit2 0x62
#define reg_digit3 0x63
#define reg_digit4 0x64
#define reg_digit5 0x65
#define reg_digit6 0x66
#define reg_digit7 0x67
#define reg_digit0a 0x68
#define reg_digit1a 0x69
#define reg_digit2a 0x6A
#define reg_digit3a 0x6B
#define reg_digit4a 0x6C
#define reg_digit5a 0x6D
#define reg_digit6a 0x6E
#define reg_digit7a 0x6F

sbit Chip_Select at RC6_bit;
sbit SoftSpi_CLK at RC3_bit;
sbit SoftSpi_SDI at RC4_bit;
sbit SoftSpi_SDO at RC5_bit;

sbit Chip_Select_Direction at TRISC6_bit;
sbit SoftSpi_CLK_Direction at TRISC3_bit;
sbit SoftSpi_SDI_Direction at TRISC4_bit;
sbit SoftSpi_SDO_Direction at TRISC5_bit;

unsigned digits[] = {0x30, 0x31, 0x32, 0x33, 0x34, 0x53, 0x36, 0x37, 0x38, 0x39};
unsigned char digitsdp[] = {0xB0, 0XB1, 0XB2, 0XB3, 0XB4, 0X75, 0XB6, 0XB7, 0XB8, 0XB9};
unsigned char alphabets1[] = {0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0X4B, 0X4C, 0X4D, 0X4E, 0X4F,
                              0X50, 0X51, 0X52, 0X53, 0X54, 0X55, 0X56, 0X57, 0X58, 0X59, 0X5A};
unsigned char alphabets2[] = {0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0X6B, 0X6C, 0X6D, 0X6E, 0X6F,
                              0X70, 0X71, 0X72, 0X73, 0X74, 0X75, 0X76, 0X77, 0X78, 0X79, 0X7A};

void MAX6954_Write(unsigned char command, unsigned char data_);
void MAX6955_Init();

void MAX6954_Write(unsigned char command, unsigned char data_)
{

   Chip_Select = 0;
   Soft_SPI_Write(command);
   Soft_SPI_Write(data_);
   Chip_Select = 1;



}

void MAX6955_Init()
{
   MAX6954_Write(reg_decodeMode, 0xFF);
   MAX6954_Write(reg_scanLimit, 0x07);
   MAX6954_Write(reg_configuration, (RUN|USE_DISCRETE));
   MAX6954_Write(reg_globalIntensity, 0x13);
   MAX6954_Write(reg_digitType, 0x00);
   MAX6954_Write(reg_displayTest, 0x01);
   delay_ms(1000);
   MAX6954_Write(reg_displayTest, 0x00);

}

unsigned char i = 0, j = 0, strvolt[23], dpset = 0;
float volt = 0.0;

void main(){

   TRISB = 0x00;
   TRISC = 0x00;
   TRISC.F4 = 1;
   CMCON = 0X07;
   ADCON0 = 0b10000000;
   ADCON1 = 0b11001110;
   CVRCON.CVROE = 0;
   Chip_Select = 1;
   //SPI1_Init_Advanced(_SPI_MASTER_OSC_DIV64, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_LOW, _SPI_LOW_2_HIGH);
   Soft_SPI_Init();
   MAX6955_Init();

   while(1){


         volt = ADC_Read(0);
         volt = volt * (5.0 / 1023.0) * 60.0;
         FloatToStr(volt, strvolt);
         j = 0;
         for(i = 0; i < 8; i++){
                 if(strvolt[i] != '.'){
                        if(dpset == 0)
                        MAX6954_Write(0x20 + i, digits[strvolt[i] - 0x30]);
                        else if(dpset == 1)
                        MAX6954_Write(0x20 + i - 1, digits[strvolt[i] - 0x30]);
                 }
                 else if(strvolt[i] == '.'){
                        MAX6954_Write(0x20 + (i - 1), digitsdp[strvolt[i - 1] - 0x30]);
                        dpset = 1;
                 }
         }
         dpset = 0;
         MAX6954_Write(0x27, alphabets2[21]);
         Delay_ms(1000);
   }
}