Differences

This shows you the differences between two versions of the page.

--- code:i2c_eeprom [2008/12/04 04:44] – laurenceb
+++ code:i2c_eeprom [2009/03/20 04:50] (current) – laurenceb
@@ Line 18: / Line 18: @@
 	u16 timeout=1;
 	TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);	//send start
-	while (!(TWCR & (1<<TWINT)) && timeout);
+	while (!(TWCR & (1<<TWINT)) && timeout)
 		timeout++;							//wait for a start to be transmitted
 	if(!timeout)
@@ Line 31: / Line 31: @@
 	u16 timeout=1;
 	TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
-	while (!(TWCR & (1<<TWSTO)) && timeout);//wait for stop to be sent
+	while (!(TWCR & (1<<TWSTO)) && timeout)	//wait for stop to be sent
 		timeout++;
 	if(!timeout)
@@ Line 42: / Line 42: @@
 	TWDR = c;								//load the data
 	TWCR = (1<<TWINT)|(1<<TWEN);
-	while (!(TWCR & (1<<TWINT)) && timeout);//wait for it to be sent
+	while (!(TWCR & (1<<TWINT)) && timeout)	//wait for it to be sent
 		timeout++;
 	if(!timeout)
@@ Line 113: / Line 113: @@
 u32 findtop()									//Find the address of record number where we enter painted eeprom
 {
-	u32 top=12*((u32)(((u32)1<<16)/12));		//half way through rounded down to nearest 12
+	u32 top=12*((u32)1<<13);					//half way through rounded down to 12
-	u08 n;
+	u08 n,endcond=TRUE;
-	u08 endcond=TRUE;							//used to solve the problem of running with n=0
+	u16 place=1<<13;
-	u16 place=5461;
 	for(n=14;endcond;)							//start by probing half way through - place is in records
 	{
@@ Line 123: / Line 122: @@
 			n--;								//need to decr here to get 1 byte resolution
 		else
-			endcond=FALSE;						//terminate the loop after completion
+			endcond=FALSE;						//terminate the loop after completion									//need to decr here to get 1 byte resolution
 		i2cstart();								//read the slave
 		i2cwrite(SLA_R);
 		if(i2cread(_NAK_)==MAGIC_NUMBER)		//see if its painted
-			place&=~(1<<n);						//set or clear the nth bit in the place holder
+			place&=~(1<<n);						//clear the nth bit in the place holder
-		else
+		if(n)
-			place|=(1<<n);
+			place|=(1<<(n-1));					//set the next bit
 		i2cstop();
 		if(place>10922)
@@ Line 135: / Line 134: @@
 		top = 12*( (u32)place );				//place is in units of 12
 	}
+	set_address(&top);
+	i2cstart();
+	i2cwrite(SLA_R);
+	if(i2cread(_NAK_)!=MAGIC_NUMBER)			//check the location to make sure its blank
+		place++;
+	top = 12*( (u32)place );
 	return top;
 }