Go Down

Topic: Controlling a MMA8452QT accelerometer. (Read 741 times) previous topic - next topic

mixania

Oct 29, 2012, 04:35 pm Last Edit: Oct 29, 2012, 05:03 pm by mixania Reason: 1
Hey, guys. I just ordered this accelerometer MMA8452QT http://www.newark.com/jsp/search/productdetail.jsp?sku=84R7353  but I have no idea how to hook it up with the I2C. It seems that It is not even possible to control it from an Arduino at all.

By reading it's data sheet made feel even worse. Can anyone help me out in controlling this guy? I would be very very thankful to the person that would provide some guidance with this guy. It would be so so so cool if I could've controlled a 1$ sensor instead of buying a 30$ kit from spark fun.

If you now were to acquire any cheap sensors (1$-3$) that output analog instead of I2C please let me know. (Preferably from newark.com)

UPDATE     UPDATE     UPDATE     UPDATE    UPDATE     UPDATE    UPDATE     UPDATE   

Hey guys, this seems like a analog one right?
http://www.newark.com/analog-devices/adxl335bcpz/accelerometer-3-axis-lfcsp-16/dp/45P6448?in_merch=Featured%20Analog%20Devices%20Products&MER=PSPSO_S_P_AnalogDevices_None
Arduino Uno R3
Mac OSX Lion

MarkT

Starting point for I2C: http://www.arduino.cc/en/Reference/Wire

You can also look at other I2C drivers for other chips and see how it all works.

Hardware wise this is a 3V3 chip, so you provide 4k7 pull-up resistors from 3V3 to both SCL and SDA - and power the chip from 3V3.

So you have bought a QFN package chip - any idea how you are going to solder that?  (Or is it on a breakout board?)
[ I won't respond to messages, use the forum please ]

dhenry

Quote
but I have no idea how to hook it up with the I2C.


Why buy it then?

Quote
It seems that It is not even possible to control it from an Arduino at all.


It is entirely possible and done everyday.

Quote
Can anyone help me out in controlling this guy?


Using i2c.

Quote
If you now were to acquire any cheap sensors (1$-3$) that output analog instead of I2C please let me know. (Preferably from newark.com)


Not sure about newark but on digital, you do select output type to be digital and it will generate many chips for you. I use mma7361 from Freescale.

dhenry

Quote
any idea how you are going to solder that?


Dead bug.

qfn is fairly easy to work with.

mixania

Arduino Uno R3
Mac OSX Lion

mixania


Starting point for I2C: http://www.arduino.cc/en/Reference/Wire

So you have bought a QFN package chip - any idea how you are going to solder that?  (Or is it on a breakout board?)


Don't worry, I have hands plus a solder station ;)

Thanks for the advise thought, really appreciate it man!
Arduino Uno R3
Mac OSX Lion

MarkT

OK, I'll rephrase my question:  how are you going to solder that and have it exactly level and aligned on the circuit board so that the X, Y, Z axes are aligned to the board?

[edit: and if you can, show us how you do it!]
[ I won't respond to messages, use the forum please ]

mixania


OK, I'll rephrase my question:  how are you going to solder that and have it exactly level and aligned on the circuit board so that the X, Y, Z axes are aligned to the board?

[edit: and if you can, show us how you do it!]


For now, i'm not worrying how exactly It would be aligned to the circuit board. I just want to solder it with whatever I could and connect it to my Arduino Uno. If necessary I would just solder it to some wires and not worry about sticking it on a board at all. If i'm going to build a project later on, then i'll consider your question once again. :)
Arduino Uno R3
Mac OSX Lion

dhenry

Quote
how are you going to solder that and have it exactly level and aligned on the circuit board so that the X, Y, Z axes are aligned to the board?


With a glue gun: drop some hot glue on the board and then push the chip's topside onto it. And solder from the bottom side (now exposed).

Also, you don't need it to be "exactly" level. Just reasonably level would do.

mixania




With a glue gun: drop some hot glue on the board and then push the chip's topside onto it. And solder from the bottom side (now exposed).



O! really? Can a glue gun glue actually conduct electricity and work as a "soldering" material?
Arduino Uno R3
Mac OSX Lion

Go Up