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What happens if SA0 is left unconnected on MMA8451Q?

Question asked by osed on Aug 6, 2015
Latest reply on Aug 10, 2015 by Tomas Vaverka

I accidentally left SA0 of an MMA8451Q on my latest board. What type of behaviour can I expect? I would assume that it either defaults to one adress (0x1C or 0x1D), is the adress determined at startup (i.e. it randomly choses one adress, but sticks to it as long as it has power) or will it continuously jump between the addresses?

The first and second scenario can easily be handled in software, but the third will be a bummer.

 

Thanks,

 

Edit: AN4077 states "Pin 7 (SA0: Address Pin), ... should all use pull-up/down resistors to ensure they maintain the state of the pin.", so I assume leaving it unconnected was a bad move.

 

Message was edited by: osed

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