Indirect Adressing

[psf]

I should ude this feature to read a large amount of data from external eeprom:
I want to read 50 position of memory so if I use the I2CreceiveBYTE macro and I save the returnvalue to variable POS0, i must repeat the same thing 50 times.
There is a specific way to create a loop and auto increment the returnValue varibale to POS1,POS2,POS3....POS49 .(external memory address increment is automatic)
In asm I could increment the FSR reg having the first memory address (POS0 ADDRESS). In flowcode I suppose the memory address of a variable may change if I add another var (looking into asm build file they are in a strange order NOT sequential and NOT alphabetical).
Thanks

[Steve]

When communication with an external EEPROM via I2C, you do not need to send the internal EEPROM address each time. But it would be useful to store the data in some kind of array. Here's an example that may help:

Code: Select all

Idx= 0
MI2C_Init()
MI2C_Start()
MI2C_Transmit_Byte(0x24)                    [address on I2C bus; R/W=0]
MI2C_Transmit_Byte(0x00)                    [start of internal EEPROM address]
MI2C_Restart()
MI2C_Transmit_Byte(0x25)                    [address on I2C bus; R/W=1]
Loop while Idx < 50
  If (Idx = 49)
    MyArray[Idx] = MI2C_Receive_Byte(1)     [1 = last byte]
  Else
    MyArray[Idx] = MI2C_Receive_Byte(0)     [0 = still receiving]
  End If
  Idx = Idx + 1
End Loop
MI2C_Stop()

This example uses a variable "Idx" which is used as an index to an array, and an array "MyArray[50]" to hold the data. Both variables are BYTEs, and the array is 50 bytes long.

At the end of this, your array should contain the values that were stored in the EEPROM between addresses 0 and 49.

[psf]

Thanks, now I learnt to use arrays!