9dof Sensor stick - HMC5843 I2C Problem! - SparkFun Electronics Forum

9dof Sensor stick - HMC5843 I2C Problem!#127952

By E.T. - Sun May 29, 2011 8:02 pm

- Sun May 29, 2011 8:02 pm #127952

Hi everyone!
Im new to the Sparkfun forum, and this is my first post! I just bought a 9dof sensor stick, and I am having some trouble communicating with the HMC5843 chip on it via I2C. Im using a PIC24F. I can talk to the ITG-3200 and ADXL435's (via I2C) just fine, but I am getting no ACK from the magnetometer. Ive triple checked all the registers, tried bit-banging and hardware I2C, and baud rates from 50Khz to 400Khz, but nothing has worked. Ive noticed the HMC5843 is a relatively old product, but I don't think thats the reason. Has anyone has this type of problem before? Thanks!

Re: 9dof Sensor stick - HMC5843 I2C Problem!#127989

By waltr - Mon May 30, 2011 3:26 pm

- Mon May 30, 2011 3:26 pm #127989

I have posted code in the PIC Code Snippits forum for the HMC6352 compass IC that I use.
A look at the mag_i2c.c file might be helpful.

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128020

By mocapeg - Tue May 31, 2011 4:40 am

- Tue May 31, 2011 4:40 am #128020

E.T, I got a couple of sticks few days ago, and i have the exact same problem as yours, i get no ACK signal from the magnetometer, gyro/acc works fine, and i know it's not a code problem cause i have 7 of the standalone breakout of the same magnetometer (HMC5843) and they all work fine, i just can't get the magnetometer of the stick to respond, and i tried two so far and they have the same problem, so if you find out what's the problem plz let me know.
Maybe the magnetometer of the last lot is defected or something, need someone from sparkfun to confirm.

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128027

By kld_555 - Tue May 31, 2011 6:59 am

- Tue May 31, 2011 6:59 am #128027

Hi All,

I have bought quite a few of the 9 dof stick, I am having exactly the same problem as E.T. I am getting readings from the ADXL and the ITG but no ACK from the HMC! I'm pretty sure the circuit is fine and that the I2C is working (I've used the same program with another I2C circuit). I am worried that the batch we got has a malfunctioned HMC

please help!

For the record: I already tried two of the 9 dof sticks I got, same exact problem

Can we have some attention from SparkFun about this

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128113

By MostlyHarmless - Wed Jun 01, 2011 10:58 am

- Wed Jun 01, 2011 10:58 am #128113

I use and MSP430 with the HMC5843. I had some trouble because of the MSP430 I2C module and the known issues. For the pic24, have you checked out the errata? http://ww1.microchip.com/downloads/en/D ... 80444D.pdf

At a glance I see several I2C issues.
Cheers,
MH

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128115

By mocapeg - Wed Jun 01, 2011 11:13 am

- Wed Jun 01, 2011 11:13 am #128115

@MostlyHarmless, it's not an issue of the i2c of the PIC, i also use PIC and i can communicate with the HMC5843 just fine (as i said before, i have the standalone breakout), but not the one on the stick that's all, so we have an issue with the HMC5843 of the stick not an issue with the HMC5843 sensor, i know it doesn't make any sense, so the only cause that i can come up with, that the HMC5843 of the stick of the last batch is defective, i only need someone to confirm it.

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128302

By belushi - Sun Jun 05, 2011 6:27 am

- Sun Jun 05, 2011 6:27 am #128302

Hi there,

I'm using the 9dof Sensor Stick with the Arduino Pro Mini. I have the problem that in the virtualization my Object continues to rotate around its own axis after i've moved it to a new position. Could it be also a problem of the HMC5843 Sensor?
The program code is from Fabio Varesano for the FreeIMU. I have modified the code but now I do not know where the fault may lie! And my fear is that it lies on the sensor.

Maybe someone have the same experience?

Best regards
Belushi

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128470

By fax8 - Wed Jun 08, 2011 2:53 pm

- Wed Jun 08, 2011 2:53 pm #128470

You guys should get in touch with sfe tech assistance.. they'll guide through the troubleshooting of the board and offer a replacement if needed.

Fabio Varesano

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128475

By sebmadgwick - Wed Jun 08, 2011 4:01 pm

- Wed Jun 08, 2011 4:01 pm #128475

ACK failure was a common complaint when SparkFun sold the HMC5843 with a cap of an inappropriate ESR. See:

viewtopic.php?f=14&t=17475&start=60&hilit=HMC5843+ESR

I think I've a got few posts in there from starting it wouldn't ACK and ending once I solved the problem.

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128477

By mocapeg - Wed Jun 08, 2011 5:04 pm

- Wed Jun 08, 2011 5:04 pm #128477

Thanx guys, but it turned out that the problem was in the board, the sensor wasn't soldered well, when i applied a bit of a pressure over it, it works. We contacted techsupport and they will send replacements soon.

Re: 9dof Sensor stick - HMC5843 I2C Problem!#128491

By fax8 - Thu Jun 09, 2011 12:44 am

- Thu Jun 09, 2011 12:44 am #128491

Yeah, unfortunately the HMC5843 is quite difficult to solder.. the HMC5883L it's even more difficult.. everyone using those sensors had these problems, no matters if using hot air & pizza oven (like myself) or fancy pick & place machines like the guys at sparkfun.

Hopefully, one year after reporting the ESR bug, they should have fixed that problem.

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