MAX7219 turn into working

[imranahmed]

Please let me know that I am interface MAX7219 with Arduino UNO and connect necessary

connection on breadboard and using common cathode 3-digit 7-segment display.

But when turn it on all digits are lit up and no data is display.

And I am using library "LedControlMS"

 

[Easyrider83]

All digits are on in test mode. You should perform initialization first.

#include "MAX7219.h"

#define MAX7219_SPI								SPI1		//interface definition
#define MAX7219_MaxCountValue			12			//maximum vaule of chips in serial to scan

/* You can manualy assign the value of chips in serialy connected here*/
unsigned char ChipsInSerial=0;	//otherwise search procedure will be needed and loop must be closed

unsigned char DigitsPerChip=8;

unsigned char MAX7219_WriteReg (unsigned char Reg, unsigned char Data);

unsigned char MAX7219_WriteReg (unsigned char Reg, unsigned char Data)
{
	unsigned char cnt=0;
	unsigned char tmp=0;
	
	if (ChipsInSerial==0) 
	{
		PIN_OFF(CS);
		for (tmp=0;tmp!=MAX7219_MaxCountValue;tmp++) SPI_SendByte(MAX7219_SPI, MAX7219_NoOperation);
		PIN_ON(CS);
		PIN_OFF(CS);
		tmp=0;
		while ((tmp!=Reg)&(cnt<MAX7219_MaxCountValue)) 
		{	
			tmp=SPI_ReadByte(MAX7219_SPI, Reg);
			SPI_SendByte(MAX7219_SPI, Data);
			cnt++;
		}
		PIN_ON(CS);
		ChipsInSerial = cnt-1;
	}
	else
	{
		PIN_OFF(CS);
		for (tmp=0;tmp!=ChipsInSerial;tmp++)
		{
			SPI_SendByte(MAX7219_SPI, Reg);
			SPI_SendByte(MAX7219_SPI, Data);
		}
		PIN_ON(CS);
	}
	return ChipsInSerial;
}

unsigned char MAX7219_Init (MAX7219Init_TypeDef * MAX7219_InitStruct)
{
	MAX7219_DisplayTestVoid(0);
	DigitsPerChip = MAX7219_InitStruct->ScanLimit+1;
	MAX7219_WriteReg(MAX7219_DecodeMode, MAX7219_InitStruct->DecodeMode);
	MAX7219_WriteReg(MAX7219_Intensity, MAX7219_InitStruct->Intensity);
	MAX7219_WriteReg(MAX7219_ScanLimit, MAX7219_InitStruct->ScanLimit);
	return MAX7219_WriteReg(MAX7219_ShutDown, MAX7219_InitStruct->ShutDown);
}

void MAX7219_StructInit (MAX7219Init_TypeDef * MAX7219_InitStruct, unsigned char DigitsPerChip)
{
	MAX7219_InitStruct->DecodeMode=0xFF;	//code B 0..7
	MAX7219_InitStruct->Intensity=8;	//0...16
	MAX7219_InitStruct->ScanLimit=(DigitsPerChip-1);
	MAX7219_InitStruct->ShutDown=1;
}

void MAX7219_DrawDigitSerial (unsigned char * Digit)
{
	unsigned char ChipCNT;
	unsigned char DigitCNT = DigitsPerChip;

	for (DigitCNT=0;  DigitCNT!=DigitsPerChip; DigitCNT++)
	{
		PIN_OFF(CS);
		for (ChipCNT=0; ChipCNT!=ChipsInSerial; ChipCNT++)
		{
				SPI_SendByte(MAX7219_SPI, (DigitCNT+1));
				SPI_SendByte(MAX7219_SPI, Digit[(ChipsInSerial-ChipCNT-1)*DigitsPerChip+DigitCNT]);			
		}
		PIN_ON(CS);
	}
}

void MAX7219_DisplayTestVoid (unsigned char Enable)
{
	MAX7219_WriteReg(MAX7219_DisplayTest, Enable);
}

void MAX7219_SetIntensity (unsigned char Intensity)
{
	MAX7219_WriteReg(MAX7219_Intensity, Intensity&0x0F);
}

void MAX7219_Power (unsigned char PowerState)
{
	MAX7219_WriteReg(MAX7219_ShutDown, PowerState);
}

void MAX7219_DrawCharSerial (unsigned char CHAR, const unsigned long (*FONT)[])
{
	unsigned char DigitArray[8];
	CHAR=CHAR<<1;
	DigitArray[0]=((*FONT)[CHAR]&0xFF000000)>>24;
	DigitArray[1]=((*FONT)[CHAR]&0x00FF0000)>>16;
	DigitArray[2]=((*FONT)[CHAR]&0x0000FF00)>>8;
	DigitArray[3]=((*FONT)[CHAR]&0x000000FF);
	DigitArray[4]=((*FONT+1)[CHAR]&0xFF000000)>>24;
	DigitArray[5]=((*FONT+1)[CHAR]&0x00FF0000)>>16;
	DigitArray[6]=((*FONT+1)[CHAR]&0x0000FF00)>>8;
	DigitArray[7]=((*FONT+1)[CHAR]&0x000000FF);
	MAX7219_DrawDigitSerial(DigitArray);
}

#include "spi.h"
#include "stm32_GPIO.h"

#define CS														GPIOA, GPIO_Pin_2

#define MAX7219_NoOperation						0xA0
#define MAX7219_DecodeMode						0xA9
#define MAX7219_Intensity							0xAA
#define MAX7219_ScanLimit							0xAB
#define MAX7219_ShutDown							0xAC
#define MAX7219_DisplayTest						0xAF


typedef struct
{
	unsigned char DecodeMode;
	unsigned char Intensity;
	unsigned char ScanLimit;
	unsigned char ShutDown;
}MAX7219Init_TypeDef;

unsigned char MAX7219_Init (MAX7219Init_TypeDef * MAX7219_InitStruct);
void MAX7219_StructInit (MAX7219Init_TypeDef * MAX7219_InitStruct, unsigned char DigitsPerChip);
void MAX7219_DrawDigitSerial (unsigned char * Digit);
void MAX7219_DisplayTestVoid (unsigned char Enable);
void MAX7219_SetIntensity (unsigned char Intensity);
void MAX7219_Power (unsigned char PowerState);
void MAX7219_DrawCharSerial (unsigned char CHAR, const unsigned long (*FONT)[]);

 

[milan.rajik]

Are you using this module ? It has 8 digits.

https://www.banggood.com/MAX7219-Re...-Display-Module-For-Arduino-MCU-p-907849.html

 

[imranahmed]

All digits are on in test mode. You should perform initialization first.

Dear Easyrider83,

I performed initialization but no effect. Only proteus simulation is running the code successfully.

void setup()
{
   /*
   The MAX72XX is in power-saving mode on startup,
   we have to do a wakeup call
   */
   lc.shutdown(0,false);
 
   /* Set the brightness to a medium values */
   lc.setIntensity(0,15);

   /* and clear the display */
   lc.clearDisplay(0);
  
   
}

- - - Updated - - -

No dear milan.rajik,

I am using my own built circuit of 3-digit 7 segment display and also they are multiplexed.

Proteus simulation is running but in breadboard all segments are lit up fully.

 

[ud23]

Proteus simulation is running but in breadboard all segments are lit up fully.

check out the clock signal on the scope.make sure you have proper clock provided at your breadboard.

 

[milan.rajik]

Please zip and post your mikroC project files and Proteus file.