Hello Marc,
Please accept our apologies for limited availability of the MMA8451Q. It is going through the assembly transfer and that is why it may be out of stock or have longer lead time, unfortunately.
However, there is a possibility to use the FXLS8471Q instead. Almost no firmware changes are necessary, just make sure to use correct slave address which is 0x1C (when SA0 = pin 10 = 0) for MMA8451Q and 0x1E (when SA0 = SA1 = 0) for FXLS8471Q. And the content of the WHO_AM_I register is different (0x1A vs. 0x6A). As for the hardware compatibility, pin 10 is address select pin SA1 on FXLS8471Q and there is no problem to have it connected to GND. And pin 3 on FXLS8471Q should be connected to GND, but I do not expect any problems if it will be left floating.
Best regards,
Tomas
