Arduino SCCB Driver for OV7670 Camera Module

SCCB_Arduino.c

#define SIO_C 2
#define SIO_D 4
#define SIO_CLOCK_DELAY 100
 
void setup()
{
  pinMode(8,OUTPUT);
  
//  while(1)
//  {
//    digitalWrite(8,HIGH);
//    delayMicroseconds(SIO_CLOCK_DELAY);    
//    digitalWrite(8,LOW);
//    delayMicroseconds(SIO_CLOCK_DELAY);    
//  }
    
  Serial.begin(9600);
  Serial.println("Start InitOV7670 test program");
  digitalWrite(8,HIGH);delayMicroseconds(SIO_CLOCK_DELAY);   
  digitalWrite(8,LOW);delayMicroseconds(SIO_CLOCK_DELAY);   
  digitalWrite(8,HIGH);delayMicroseconds(SIO_CLOCK_DELAY);   
 
  if(InitOV7670())    
    Serial.println("InitOV7670 OK");
  else
    Serial.println("InitOV7670 NG");
  
  
}
 
void loop()
{
}
 
 
void InitSCCB(void) //SCCB Initialization
{
  pinMode(SIO_C,OUTPUT);
  pinMode(SIO_D,OUTPUT);
  
  digitalWrite(SIO_C,HIGH);
  digitalWrite(SIO_D,HIGH);
  
  Serial.println("InitSCCB - Port Direction Set & Set High OK");
}
 
void StartSCCB(void) //SCCB Start
{
  Serial.println("StartSCCB");
 
  digitalWrite(SIO_D,HIGH);
  delayMicroseconds(SIO_CLOCK_DELAY);
  
  digitalWrite(SIO_C,HIGH);
  delayMicroseconds(SIO_CLOCK_DELAY);
  
  digitalWrite(SIO_D,LOW);
  delayMicroseconds(SIO_CLOCK_DELAY);
  
  digitalWrite(SIO_C,LOW);
  delayMicroseconds(SIO_CLOCK_DELAY);
}
 
void StopSCCB(void) //SCCB Stop
{
  //Serial.println("StopSCCB");
 
  digitalWrite(SIO_D,LOW);
  delayMicroseconds(SIO_CLOCK_DELAY);
  
  digitalWrite(SIO_C,HIGH);
  delayMicroseconds(SIO_CLOCK_DELAY);
  
  digitalWrite(SIO_D,HIGH);
  delayMicroseconds(SIO_CLOCK_DELAY);
}
 
bool SCCBWrite(byte m_data)
{
  unsigned char j;
  bool success;

  for ( j = 0; j < 8; j++ ) //Loop transmit data 8 times
  {
    if( (m_data<<j) & 0x80 )
      digitalWrite(SIO_D,HIGH);
    else
      digitalWrite(SIO_D,LOW);
  
    delayMicroseconds(SIO_CLOCK_DELAY);
    
	
	digitalWrite(SIO_C,HIGH);
	delayMicroseconds(SIO_CLOCK_DELAY);
    
	digitalWrite(SIO_C,LOW);
    delayMicroseconds(SIO_CLOCK_DELAY);
  }
 

  digitalWrite(8,LOW); //debug
  
  pinMode(SIO_D,INPUT); // I pass a bus of SIO_D to slave (OV7670)
  digitalWrite(SIO_D,LOW); // Pull-up prevention  --this line is not present in embedded programmer lib
  delayMicroseconds(SIO_CLOCK_DELAY);
 
  digitalWrite(8,HIGH); //debug
  
  digitalWrite(SIO_C,HIGH);
  delayMicroseconds(SIO_CLOCK_DELAY);
 
  digitalWrite(8,LOW); //debug
  
  if(digitalRead(SIO_D)==HIGH)
    success= false;
  else
    success= true; 

  digitalWrite(SIO_C,LOW);
  delayMicroseconds(SIO_CLOCK_DELAY);	
  
  pinMode(SIO_D,OUTPUT); //Return the bus of SIO_D to master (Arduino)
  
  //delayMicroseconds(SIO_CLOCK_DELAY);	
  //digitalWrite(SIO_D,LOW);
  //delayMicroseconds(SIO_CLOCK_DELAY);	
 
  //pinMode(SIO_C,OUTPUT); //Return the bus of SIO_C to master (Arduino)
 
  return success;  
}
 
bool InitOV7670(void)
{
  char temp = 0x80;

  InitSCCB();
  
  if( ! WriteOV7670(0x12, temp) ) //Reset SCCB
  {
    Serial.println("Resetting SCCB Failed");
    return false;
  }

  return true; 
}  
 
////////////////////////////
//To write to the OV7660 register: 
// function Return value: Success = 1 failure = 0
bool WriteOV7670(char regID, char regDat)
{
	StartSCCB();
	if( ! SCCBWrite(0x42) )
	{
        Serial.println(" Write Error 0x42");
  		StopSCCB();
		return false;
	}
	
	delayMicroseconds(SIO_CLOCK_DELAY);

  	if( ! SCCBWrite(regID) )
	{
		StopSCCB();
		return false;
	}
	delayMicroseconds(SIO_CLOCK_DELAY);
  	if( ! SCCBWrite(regDat) )
	{
		StopSCCB();
		return false;
	}
	
  	StopSCCB();
	
  	return true;
}

Can you share the hardware setup

Can you share the hardware setup

Hi @Madhuri1398 , it was a very long time ago. I don't really remember hardware details at this point.