在Raspberry 上面使用ADXL345

Step 1: Setting up the Raspberry pi for the ADXL 345

ADXL 345 pin out 圖

 RPI GPIO 圖

The ADXL345 supports both I2C and SPI connections, I used I2C, which requires some configuration on the Pi:

使用I2C 來連線.....

Use the GPIO diagram above to help with the wiring

GND - GND 

3V - 3V3

SDA - SDA

SCL - SCL

check 一下系統有沒有把I2C關掉

Add the I2C modules to the Pi's configuration:

sudo nano /etc/modules

Then add the following lines:

i2c-bcm2708
i2c-dev

Remove I2C from the blacklist:

sudo nano /etc/modprobe.d/fbdev-blacklist.conf

Change this:

blacklist i2c-bcm2708

To this:

#blacklist i2c-bcm2708

Reboot to make the changes:

sudo reboot

Step 2: Installing the Stuff

You will need to install smbus:

sudo apt-get install python-smbus i2c-tools git-core

Now test the ADXL345 is found on the I2C bus by running:

sudo i2cdetect -y 1

看的出來address 0x53的地方有device....

如果沒有看到0x53...代表你線接錯了...或是i2c關掉了

Now download from

https://github.com/pimoroni/adxl345-python

不太會使用gitcore.....  所以我從網頁右上角有個 Download Zip..... 按下... 然後用ftp 傳到RPI...

cd adxl345-python-master

Then write:

sudo python example.py

If you get 0.000G for all axis then something probably isn't set up correctly.

看一下  example.py

from adxl345 import ADXL345

adxl345 = ADXL345()

axes = adxl345.getAxes(True)

print "ADXL345 on address 0x%x:" % (adxl345.address)

print "   x = %.3fG" % ( axes['x'] )

print "   y = %.3fG" % ( axes['y'] )

print "   z = %.3fG" % ( axes['z'] )

解釋如下 :

#import the adxl345 module
import adxl345

#create ADXL345 object 

accel = adxl345.ADXL345()

#get axes as g 

axes = accel.getAxes(True) 

# to get axes as ms^2 use  

axes = accel.getAxes(False)

#put the axes into variables 

x = axes['x'] 

y = axes['y'] 

z = axes['z']

#print axes 

print x 

print y 

print z

Change the program for fun!

The default range is 2g which means that the maximum G the ADXL345 can measure is 2.048, but at a high degree of sensitivity.

You can change the sensitivity of the ADXL345 by using the .setRange() method of the class.

這邊還有另外一個sample code

Firstly download their file from:

http://www.sunfounder.com/index.php?c=downloads

From there download the User manual(Super Kit for Pi) and the Code and Frizting(Super kit for Pi)

會看到兩個code ...

也是可以參考一下......  

Reference : http://www.instructables.com/id/how-to-use-the-ADXL345-on-Raspberry-pi/