# [Q][Triple Axis Accelerometer][DFR0143]How to have a speed in m/s with this obj?

Hi everyone, sorry i'm a newbie and a noob in arduino development (and sorry for my bad english). First, i'm sorry if it's the good place to post this thread. I'm using a triple axis accelerometer, but i don't understand how with these information (X, Y , Z) can i have a speed (m/s). Here it's the wiki page of the product: http://www.dfrobot.com/wiki/index.php/Triple_Axis_Accelerometer_MMA7361_%28SKU:_DFR0143%29#Sample_Code

I'm using a triple axis accelerometer, but i don't understand how with these information (X, Y , Z) can i have a speed (m/s). Here it's the wiki page of the product: http://www.dfrobot.com/wiki/index.php/Triple_Axis_Accelerometer_MMA7361_%28SKU:_DFR0143%29#Sample_Code

You cannot find the speed using the accelerometer right now, I wanted to do the same sometime back but due to the working physics of an Acc.. involved it wasn't possible .

NI\$HANT:

I'm using a triple axis accelerometer, but i don't understand how with these information (X, Y , Z) can i have a speed (m/s). Here it's the wiki page of the product: http://www.dfrobot.com/wiki/index.php/Triple_Axis_Accelerometer_MMA7361_%28SKU:_DFR0143%29#Sample_Code

You cannot find the speed using the accelerometer right now, I wanted to do the same sometime back but due to the working physics of an Acc.. involved it wasn't possible .

Ok, thanks for your quick answer, so my microcontroller is useless ? x) I thought using it just for have a speed...

Well you can measure speed using many other available ways. The thing is which objects speed you wanted to measure?

NI\$HANT: Well you can measure speed using many other available ways. The thing is which objects speed you wanted to measure?

Sorry, it's my fault that i not precise why i would like to have speed. I'm actually building firefighter robot prototype for my high school project. And so, i would like to measure the speed of the robot Photos (it's just the chassis): http://image.noelshack.com/fichiers/2014/14/1396518659-20140402-085024-0.jpg

use a rotary encoder or quadrature encoder:

see the polulu website for this.

there is a lot of ways to measure the speed on your car.

Use hall sensor (Allegro A1302) and magnet (on drive shaft).