Gyro I2C problem, Crius SE v0.2

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olex
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Gyro I2C problem, Crius SE v0.2

Post by olex »

Hello,

I've recently bought a used Crius Multiwii SE v0.2 board on eBay for my quadcopter build, and got it today. I've successfully updated the firmware to MultiWii 2.1 and got the board to talk to the PC software, but there seems to be a problem with the gyro sensor. The I2C error counter in the software is constantly counting up and overflowing, and the gyro values are always 0. All other sensors (ACC, MAG, BAR) are working, and after calibrating them the GUI correctly shows the copter's orientation - but it updates very slowly, I'm pretty sure it won't fly without gyros working.

The gyro sensor is an ITG3205 (verified my looking at the chips myself). The sensors are correctly configured in the firmware, I've double-checked it - the stock configuration for the Crius SE lists the correct sensors. Other things I've tried: changing I2C frequency, enabling internal I2C pull-ups, trying the last dev MultiWii build.

I really hope this isn't it, but looks to me like the sensor or the board wiring is bad. I contacted the eBay seller to check if the board was flyable before. Still, is there anything else I can do on my end to maybe fix this?

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Hamburger
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Re: Gyro I2C problem, Crius SE v0.2

Post by Hamburger »

You did the right things.
Either fix the board now, get a new one or attach another gyro to i2c. Make sure to use one with different i2c address.

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olex
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Re: Gyro I2C problem, Crius SE v0.2

Post by olex »

How would I go about fixing it? I have some basic soldering skills (enough for wire splicing and bullet connectors), but nowhere near small enough a soldering iron for the chip pins. Would "baking" the board be an option to consider (similar to how some people repair broken solder on graphic cards)?

Btw, the board seller said the board was new and unused, but other ones from the same batch work fine.

edit Okay, so I researched Arduino and I2C a bit, and found a simple I2C scanner sketch. Sure enough, running it shows I2C devices at 3 addresses, but none at 0x68 or 0x69, which is where the gyro would be. So it's definitely a hardware fault with the board, presumably a loose solder connection.

cardboard
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Re: Gyro I2C problem, Crius SE v0.2

Post by cardboard »

you can try reflowing the board using a heat gun.
I had a similar issue and documented it over in this thread
viewtopic.php?f=16&t=2747

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Hamburger
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Re: Gyro I2C problem, Crius SE v0.2

Post by Hamburger »

could also be the gyro smd being faulty?
Get a magnifying glass and look at the soldering of gyro. Then heat board with heat gun like cardboard described? Really I am not good with that tiny stuff.

You can always just attach another gyro to i2c. No interference on i2c with that dead one.

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olex
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Re: Gyro I2C problem, Crius SE v0.2

Post by olex »

Well, I've now managed to source a replacement board, so it's not a primary concern anymore. Still, I'd like to try and get this fixed. Taking it to my university tomorrow to let some guys in the hardware lab take a look.

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