Great board but it has some I2C compatibility issues. I downloaded the example code but was surprised to see it did not use the standard Wire library. I was able to rewrite the code to use Wire but learned about an issue this board has with the Wire.endTransmission() function. Unlike other devices, the MMA8452 (and some other I2C devices as well) need a flag to keep the I2C connection alive during a read sequence. The issue is described here: http://arduino.cc/en/Reference/WireEndTransmission When I used Wire.endTransmission(false), it fixed the problems I was having with the standard wire library.

However, there is still one major limitation if you plan to use this device with an ATTiny device (as I had). The TinyWireM library does not implement the false flag in its TinyWireM.endTransmission() so, until that feature is added, you can't use this board with ATTiny devices - a serious bummer. If anyone has a workaround - please let me know.

HELP ME !!! The example code is fails c (0x0D) no return 0x2A. I doing wrong?

What are the pros or cons of this device relative to other digital-interface 3-axis accelerometer chips that are available?

If i supply this board with 5v and a voltage divider (R1 330ohm R2 660ohm giving 3.333v) would it work? and would the extra 0.033v be to high for it?

hi, i want to ask a question, for this accelerometer, 2g--1024 counts/g 4g--512 counts/g 8g--256 counts/g how can i convert counts/g unit to mV/g or V/g?, could yo help me? thank you

I can't get the basic sample to run on Teensy 2.0 Any idea on what's going on?

It chokes on the first call to the wire lib.

I was able to modify the RedBot accelerometer (MMA8462Q) CPP file to add two's complement checking and LSB shifting ala the advanced example in the Example Code above. Everything works as expected EXCEPT the g values are four times too large. I checked and double checked that the scale setting is +/- 8 g, I'm in the low res mode, the logic looks fine, and I'm dividing the count by 256 for the 8 g scale and I am getting ~+4.00 g in the z-direction, not ~+1.00 g as I expect. I'm using 8 for the scale factor in constructing the divisor for the counts (1/(1<<12)/(2*SCALE)) = 1/256 for 8 g full scale, yet I am getting an extra factor of four. I checked the raw output of the concatenated z-bytes which was ~16000 unshifted = 14-bits! What gives???

Any suggestions for what could be going wrong? Thanks.

I am working on my first Arduino project, and looking to interface with an Accelerometer to attach to the back of a washing machine. I want to monitor, and determine if its moving (i.e. ON). Do you think this is sensitive enough? Anyone got an suggestions? (It's not for homework, its a part of random idea process for a handicapped person in my neighborhood) Thanks.

I want to confirm what some other comments have said. I am using my MSP430G2553 launchpad, Energia and the Basic Example from Sparkfun at 3.3V.

The 10K pull ups are too large. I connected the SCL and SDA lines to an oscilloscope and they are rounded off horribly. It explains why my plotted data from the chip is incredibly "noisy."

4.7kΩ pull ups work great though. The SCL and SDA aren't exactly square, but are less rounded and the plotted data is clean.

Sparkfun, as other have suggested from years ago, please sell off the stock you have and revise these boards to R1=R2=10kΩ.

I am using an Arduino Mega. When i upload the basic code it reads out "MMA8452 Basic Example" then nothing else.

How can I use this item with the BOB-00099 RTC module? I am using Arduino mega/uno.

I noticed that you guys sell the MMA8452Q separately and also that the I2C addresses (you can choose between two by default) can be designated at the factory. I need to have up to 8 of these functioning on the same microcontroller, is there any chance you guys can request address reconfiguration on a few units so that I can order them through you? I love this little breakout board.

So I've been using these, and normally they work fine, but recently, they have started shorting on me. They'll be working fine, then all of a sudden, I'll resupply power and nothing will work. If I remove the the MMA8452, everything else works. Then when I test the pins on the actual breakout using a multimeter (with it removed from the breadboard I am using), there is continuity between VCC and GND. I am running everything off of a 9v battery plugged into the RAW pin of an 3.3v Arduino Pro Mini, which properly regulates down to 3.3v as expected (verified with multimeter). I can swap in a different MMA8452 and everything works again. I have soldered standard straight pin headers to all of the breakouts, but I can't imagine that that is the issue, since it only happens after using the accelerometer for a little while, so I don't think it is a solder bridging issue, but I suppose it could be.

Any ideas as to what might be happening? Is there anything that might cause a working PCB to short, or did I just get unlucky with the manufacturing? I would like to be able to fix anything that I can, since I've already killed 2 and only have 1 left to work with, and I would rather not buy more if the issue is going to keep happening.

If anyone gets this working on a Due on either set of ports, please let me know.

Thanks.

The example code (https://github.com/sparkfun/MMA8452_Accelerometer/tree/master/Firmware/MMA8452Q_BasicExample) doesn't work with an Arduino Leonardo. The Leonardo runs okay for 15 to 30 seconds, then hangs.

hello,

i am attempting to cross-compile this example MMA8452Q aduino code for the raspberry pi:-

https://github.com/sparkfun/MMA8452_Accelerometer/tree/master/Firmware/MMA8452Q_BasicExample

i am getting all sorts of missing library and header errors (all of which i located in the "arduino-1.0.4" folder i downloaded). trouble is, every time i satisfy one library, i get a new error the next time.

1) is it possibly to compile this code without the arduino compile environment (ie just a standalone linux gcc compile) ?? 2) if so, how do i satisfy the library requirements, since the needed files are scattered all over the "arduino-1.0.4" folder ?? 3) does anyone have a simple makefile or shell that i can use to satisfy the dependencies? (better yet, anyone done this for the raspberry pi???)

sorry if this is a silly endevour-i want the code but i dont want all the arduino fluff that goes with it.

thanks!

andrew.

Hello everyone! I have read the datasheet and the AN4076. On page 5 of the AN4076 it sais that with an ODR of 800Hz every sample the time detween every sample will be 1.25ms.So if i am interested in reading only one axis its value will be refreshed every 3.75ms? can't this get faster?(for example turn off the sampling on the othr two axes?) Another confusing point is at the AN4075 where it is stated on page 6 that the internal sampling rate is 1600Hz.The max 800Hz ODR is computed with the oversampling of two samples on the internal sampling frequency?

I have bought this accelerometer and I am using it with arduino uno. I have used the sample code from this just to display the x y z axis.But i am getting an error in the serial port. It basically is not able to pick up the value stored in WHO_AM_I register. Can anyone please help me.

Thanks for the sample code. Would have taken me a few days to put together but I was up and running in under 5 mins!

I have the pull up resistors wired up like the schematic, and then everything hooked into the arduino from the instruction in the advanced example. I am getting could not connect to mma8452q:0x1a. Any ideas?

Hello SparkFun friends. My kids and I are new to Arduino and, in connection with work I'm doing with Sandy Hook Promise, starting to experiment with how we'd build a tampering detector for firearms.

First step, we've acquired a SparkFun Arduino kit and one of these 10955 / MMA8542Q accelerometer breakout boards. And, we quickly got stuck. Here's what we've done:

Here's how we connected things:

10955 / Arduino

3.3V => 3.3V

Gnd => Gnd

SDA => A4

SCL => A5

ID1 => 1

ID2 => 2

I haven’t added any circuitry to pull up the 3.3V logic signals to 5V — it sounded from the discussion like that shouldn't be necessary. (Am I missing something?)

We're using the code and libraries linked below, and it's hanging so long as the SCL pin is connected.

Here's the relevant code:

#include <I2C.h>

#include <MMA8453_n0m1.h>

MMA8453_n0m1 accel;

void setup()

{

Serial.begin(9600);

accel.setI2CAddr(0x1d);

I2c.begin();

accel.dataMode(true, 2);

}

In particular, the call to accel.dataMode(true, 2) doesn't return if SCL is connected. Removing SCL connection, it proceeds into loop() but there's (obviously) no meaningful data coming through.

Stuff I’ve tried that doesn’t change behavior: – adding I2c.begin() – disconnecting I1/I2 – either address 0x1c to 0x1d

Seems strange to me that the behavior is the same regardless of address.

Thanks for advice!

I bought this to use with a Raspberry Pi and unfortunately determined these two devices are incompatible. The incompatibility is a result of the RPi not sending repeated starts correctly. Basically, the RPi can write to any register but can only read the first 7 registers on this device.

Anyone having trouble setting the dynamic range to 8G? I have comms working, and can verify the device ID and read data. However, my data is always coming in with a 2G dynamic range, even when I set XYZ_DATA_CFG to FS1.

I bought this to make the classic “Oh Fudge!” Prank.

I didn’t want to spend $28 on a ADXL345 Accelerometer, when the MMA8452Q is a much cheaper. The only down side to the MMA8452Q, is the lack of a Arduino Library for it.

So, I decided to offer the Arduino Code I used to make the “Oh Fudge!” using a MMA8452Q.

Here it is: http://pastebin.com/JKPSFxAe

I hope that helps all you “Oh Fudge!” Makers!

I would like to suggest that if you are going to keep putting pull-up resistors on breakout boards (as if they were the ONLY thing on the I2C bus), that you also provide jumpers so that they can be easily removed without having to desolder 0402 smt resistors. Thanks.

Can you Offer Variations of this with different I2C Addresses? It would be great to be able to read several of these at once. I see there are provisions for handling two variations, but I'd like a couple more.

It would be simple if you would mark them 1A,1C,1E and give a different versions. then the with the SDA line make them shift to 1B, 1D, 1F.

That would make it easy enough to chain 6 together for more complicated solutions using single I2C lines.

Thank you, -Sean Reynolds

Has anybody been using this with Netduino? I can only partly access the registers. Following are some parts of the code I wrote:

// Freescale MMA8452Q I2CDevice.Configuration Conf = new I2CDevice.Configuration(0x1D, 50); I2CDevice icD = new I2CDevice(Conf);

        byte[] data = new byte[7];

// Set it Active (This part works correctly) I2CDevice.I2CTransaction[] writeTransaction = new I2CDevice.I2CTransaction[] { I2CDevice.CreateWriteTransaction(new byte[] {0x2A, 0x01}) }; int bytesWritten = icD.Execute(writeTransaction, 50);

// Try to read Device ID (This part does not work correctly) I2CDevice.I2CTransaction[] rwtransaction = new I2CDevice.I2CTransaction[2] { I2CDevice.CreateWriteTransaction(new byte[1] { 0x0D }), I2CDevice.CreateReadTransaction(data)

            };
        int bytesRead = icD.Execute(rwtransaction, 50);
        Debug.Print(ByteToInt(data[0]).ToString());

It seems that the read register is not set to 0x0D, but that it is set to 0X00, hence the byte array "data" contains the content of the registers starting at 0X00.

Has anybody made the same experiences and found a way how to address this?

Thanks - Thomas

Are there any non-arduino code examples for how to use this?

I have two questions:

1) How/where do I complete the jumper to the SA0 pin. I plan on using four of these, in 2 groups.

2) What can I do to monitor two separate accelerometers with the same address. I need a way to combine them so I can tell when one is accelerating. Doesn't matter whether one is moving or both, just need to identify motion.

Thanks in advance.

I adapted the I2C library used in the example code to work with the new Arduino Leonardo which uses an ATMEGA32U4 instead of an ATMEGA328.

I've uploaded the changed i2c.h file to a bitbucket repository in case anyone else is interested in that: https://bitbucket.org/wizard23/arduinoleonardolibraries/src/39d52819baae/i2c.h

If you just replace the i2c.h from the above Example Code then it should work on the arduino Leonardo (or any other ATMEGA32U4 board)

The only thing I had to change was the definitions of WRITE_sda and READ_sda because that pin is on a different port on the ATMEGA32U4.

I used the sensor in my own design (thanks sparkfun for the eagle library (although I had to adapt it because the NC pins are not connected to the package and according to Freescale Application Note AN4077 you should connect dummy traces to the NC pins...)) and now I can already read the sensor values :)...thanks again to sparkfun for this awesome code example!

Will it be safe to run this straight off of a li-ion?

When I apply input voltage 3.3V to the power pin all the pins go high 3.3V with exception of ground including the Int pins. From what I read in the spec this doesn't seem right at all? They don't change no matter what I do connected or unconnected..The device reads back 0xff...Has anyone measured the voltage on the pins immediately after applying power? I wonder if I got a bad board?

I got this to work with Arduino v23 using the provided software, but can not get it to compile using Arduino V 1.0.1. Cleaned up most of the error messages (going from 23 to 1.0.1) Still no luck. Has anyone used this board and provided software with Arduino v1.0.1??

I found working library for this module: MMA8452 Library and Examples All is working fine.

I was connected this module to arduino uno via logical level converter but example code doest work, "could not connect to MMA8452Q: 3B" Can you help me ?

If I'm powering one of these off of the 3.3 volt pin on an arduino that is talking to other 5 volt devices, do I need a logic level converter like http://www.sparkfun.com/products/8745 to insure the signals are 3.3?

The comments in the example code seems to imply the code takes care of the issue so I would not, but I don't see how it does that.

I have this thing hooked up to an adruino nano 2.3. I am not receiving any error notes in the serial monitor but all I'm getting are 1s and 0s when it is moved. I see in the code it is set to show that when the orientation changes but I can't get it so show any x, y, or x values. I see the 1s and 0s when my serial monitor baud rate is 9600. When I change it to 115200 like I see in the code noting shows up. Help?

Hey guys,

I've triple checked my connections between this board and the UNO:

V3.3->3.3 GND -> GND A5 -> SCL A4 -> SDA 2 -> i1 3 -> i2

The example program fails because the WHO_AM_I register (0x0D) is returning 0x39, not 0x2A. Any idea what I could be doing wrong?

What are the dimensions of the board? .7x.7 ? It would be nice if that was part of the specs or features or something. I don't want to have to load the eagle files to figure it out.

Also, AdrianFreed has a good point and you should update the board to follow MFG guidelines.

I am putting this on my current design because our tech can't solder LCC's by hand.

Hi, Please rev. this to follow the manufacturers recommendations (i.e. 4.7k pullups, non central placement, no holes near package, traces off all pads) from AN4077.

Can you make one with the higher res. MMA8451Q too? It would be good to have the 5v regulator on there too like the competitive board from LongQi

MattTheGeek designed a similar board.

I have sooo been waiting for this: a cheap, 3 axis accelerometer on a breakout board. Yay!

You guys have so many neat accelerometers that I imagine some people have a hard time choosing. Can you do some kind of comparison table? That would be awesome! Thanks,