I'm pretty new to all this so I appreciate any help.
I'm wondering if it's possible for me to use 8 accelerometers without multiplexing. The accelerometer is the MMA8451 accelerometer from Adafruit that uses i2c:https://learn.adafruit.com/adafruit-mma8451-accelerometer-breakout/overview
(To answer my question I've been trying to find out how many addresses there are for this sensor, but I'm not sure how to figure that out....)
Thank you for any advice!
Looking at the datasheet for the standalone chip, you can change the address of the device by changing the state (high/low) of pin SA0 Look at page 17.
So...if you apply a HIGH voltage to pin SA0, the address is 0x1D and if you pull the SA0 pin LOW, the address is 0x1C.
You will want to wire up the 8 accelerometers on to an I2C BUS. Then you want separate connections (or the use of a shift register) to the pin 7 (SA0 pins) on each sensor.
The sensor you want to read from, you make its pin SA0 HIGH and communicate to address 0x1D.
In fact, the adafruit expansion boards label that pin as 'A' on the boards and give clear instructions here: