I use a MMA8452 accelerometer to measure the position in which my project is .
however, it is not very fast, is it due to i2c or the sensor ?
is there a better sensor ?


You might want to look at the ST LIS3DH (datasheet), which is also I²C and has output rates up to 5kHz (the MMA8452 goes up to 800Hz).

The LIS3DH also has the advantage that there’s a ready baked code library for it.

this is really the only criterion which will increase the data read speed ?

I really seeks to be precise as an iphone for example

the electric imp he is able to read at this speed
or can I get this component ?


The iPhone 4 and 4S used the LIS331DH accelerometer and the LIS3DH is the updated version for that part so it is certainly possible to get iPhone quality results out of it. You will need to write new software to take advantage of the FIFO to capture high speed data in a single reading.

the LIS331DH has a data rate of 0.5 Hz to 1 kHz.
while the LIS3DH has a data rate 1 Hz to 5 kHz.

MMA8452 goes up to 800Hz , it is similar to LIS331DH

where i can find LIS3DH ? for my test


OK thank you
I do not find the component with the pcb .
I found the only component in a french supplier

Googling found this:

thanks you for your help !!!

I found what I would like …
order to know the position of a cube in space

based on madgwick_algorithm

I have to use a gyroscope
an accelerometer and a magnetrometre

Try any one of these breakout boards.