External slots with other i2c device.

[tarzan]

Hi all

Now I have done some testing with this, but just to make sure I’ll put the question out there. When running external slots is it ok to have another i2c device on the i2c bus such as DS1307?

So for instance I run slot 0 with DS1307 and do non-i2c things in slot 4.

This from the manual:

Running a program from external i2c has some restrictions
1) The i2c bus is reserved exclusively for the program reading
2) The i2c pins cannot be used for any other purpose
3) Any hardware i2c/spi commands are completely ignored
4) Program execution speed is reduced, due to the relatively slow speed of
reading data from the external 24LC128
The external 24LC128 only stores the program memory space. Any download
data memory information (ie from the EEPROM command) is not stored
externally. Read and write commands continue to act on the internal PICAXE
EEPROM data memory space.

 

[Technical]

The firmware assumes that the i2c pins are dedicated to i2c use when any external slot is used. Therefore as soon as 'run 4' processes from that point on it is assumed that the i2c bus is for the program slot only. So the 'formal' answer is that i2c should therefore be reserved for program use only.

That said, if you then re-issue a 'run 0' the i2c bus will not be in use any more until slot 4 is re-started. So you may well get away with using the i2c bus for other things during slot 0.

 

[tarzan]

OK thanks for your answer.
I will proceed with my plans until I run into problems, its all learning anyway.