MMA7260 Triaxial Acceleration Higher Sensor

I have recently purtchesed one of these: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280523543745&ssPageName=STRK:MEWNX:IT#ht_3299wt_1137

i just got it conected it upt to the arduino but all i get is numbers around 500 they flicker a bit all the time but dont cahnge notesably hwen i move it somone have got an idea.

pls help!!

Can you show us the sketch you're using? The schematic doesn't seem to be available (there's a link but there's nobody home) so it's tough to figure out what could be wrong. I'm worried you're driving the accelerometer with 5V instead of 3.3V. A reading of 500 suggests it's putting out about 2.5V with no acceleration, but this 3.3V part should be putting out about 1.65V with no acceleration.

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Here is the schematics that work: http://www.freescale.com/files/sensors/doc/data_sheet/MMA7260QT.pdf http://www.satistronics.com/myfiles/file/Module/7260%20shematic%20diagram.pdf

and my code:

#define xpin    0
#define ypin    1
#define zpin    2

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  Serial.print("X:");
  Serial.print(analogRead(xpin));
  Serial.print(" Y:");
  Serial.print(analogRead(ypin));
  Serial.print(" Z:");
  Serial.println(analogRead(zpin));
  delay(100);
}

and the result:

X:343 Y:343 Z:510   //not moving
X:343 Y:337 Z:515
X:344 Y:336 Z:509
X:341 Y:340 Z:509
X:344 Y:338 Z:505
X:344 Y:340 Z:515
X:347 Y:344 Z:525   //Around here i started moving
X:348 Y:330 Z:539
X:334 Y:331 Z:456
X:337 Y:338 Z:499
X:338 Y:342 Z:541
X:342 Y:340 Z:509
X:348 Y:332 Z:478
X:335 Y:336 Z:423
X:339 Y:346 Z:550
X:352 Y:340 Z:567
X:340 Y:354 Z:508
X:336 Y:343 Z:466
X:353 Y:343 Z:453
X:346 Y:340 Z:565
X:350 Y:330 Z:581
X:345 Y:349 Z:490
X:338 Y:335 Z:461
X:352 Y:331 Z:458
X:343 Y:345 Z:542
X:339 Y:342 Z:500
X:338 Y:337 Z:506
X:326 Y:321 Z:520
X:340 Y:340 Z:512
X:341 Y:343 Z:503
X:336 Y:344 Z:516
X:345 Y:348 Z:505
X:339 Y:340 Z:519
X:337 Y:345 Z:509
X:340 Y:339 Z:510
X:341 Y:343 Z:512
X:341 Y:344 Z:512
X:344 Y:348 Z:502
X:336 Y:338 Z:511
X:337 Y:344 Z:509

Didn't see any code :)

Good start though. How are all the jumpers in the schematic set on the actual PCB? How is the accelerometer board connected to the Arduino?

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Here is my conections.

This actually looks right. Why do you think it's wrong? Acceleration doesn't last a very long time. With 100ms in between readings, you're not going to see a lot of change.

Try holding your accelerometer in different orientations (landscape, portrait, tilt right, tilt left, etc.) and you should see larger variations on all 3 channels.

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i have tride to remove the delay the serial print out dosent lock anny diferent

Does it look any different when you rotate the accelerometer to different positions?

How are jumpers J1, J2, and J3 set on the board?

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on teh output is always the same. and there are no jumpers only g1 and g2

and there are no jumpers only g1 and g2

What does this mean? Are there or are there not jumpers installed in J1 and/or J2?

More importantly, with no jumper on J3 it is possible pin 12 on the accelerometer is floating low which puts it in sleep mode. This pin needs to be high (3.3V) for normal operation.

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ok i vil test this the pin 12 has a soldering conection to it but no pin for the bread board

this diden't work

Did you found the problem? Because I'm also having problems with this sensor.. Using the same sketch as above, this is my output:

X:887 Y:911 Z:348
X:635 Y:712 Z:790
X:141 Y:908 Z:992
X:298 Y:857 Z:817
X:798 Y:541 Z:854
X:1006 Y:291 Z:969
X:981 Y:315 Z:957
X:738 Y:780 Z:579
X:972 Y:1023 Z:303
X:996 Y:1010 Z:106
X:876 Y:850 Z:458
X:465 Y:793 Z:865
X:27 Y:878 Z:884
X:691 Y:659 Z:773
X:957 Y:210 Z:976
X:939 Y:398 Z:913
X:734 Y:829 Z:490
X:994 Y:1023 Z:222
X:983 Y:977 Z:227
X:653 Y:677 Z:732
X:166 Y:894 Z:981
X:233 Y:871 Z:843
X:761 Y:586 Z:829
X:986 Y:163 Z:974
X:892 Y:490 Z:861
X:802 Y:873 Z:410

I'm not moving and still are those values changing.. Does someone have a clue?

My connections: Vcc - 3.3V GND - GND X - Analog In 0 Y - Analog In 1 Z - Analog In 2 GS1 - GND GS2 - GND SLP - 3.3V

I'm using an Arduino Mega thx

Sorry to cut in, but I like to know what Software you are using to make the picture of the connections in this post??

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1281552425#4

Thank you :-)

I've got a quick question aswell, I'm new to this kind of programming and recently got a project for doing an application which involves a MMA7260QT and an arduino table with a ATMEGA328P. I tried using Napsther's code to simply get it running and start messing around with it, but I'm getting compilation errors. Something with serial not being declared. There for after this small "wall of text" I'm wondering what it is I have to include to make it work? :> What includes are you, Napsther using? Help is appriciated!