Sensors: IMU, Magnetometer

There is reference on some RVR web pages to a magnetometer, i.e. compass. The programming access to it is not specified that I can find. Is there actually one onboard?

What is the IMU? Usually this is an amalgamation of accelerator, gyroscope, and compass. Is the IMU an actual device or a software fusion of sensor data?

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Hey @rmerriam!!

Funny that you should ask… I was just chatting with someone yesterday about how the magnetometer is, indeed, on board, but is not yet programmable (even in the currently released internal firmware). This is one of the things planned for the Q1 Firmware update :slight_smile:

In regards to the IMU, you can actually see it in your bot! (in the center, below where it says “Sphero”):

I’ll work on getting you a bit more information on IMU, but wanted to get you what I had thus far :slight_smile:

Kelsey

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Hello there!

The IMU in RVR has indeed a 3 axis accelerometer, a 3 axis gyroscope, and a 3 axis magnetometer.
As @brightnbubbly mentioned, it is a small chip in the middle of the RVR board.
We have some algorithms to transform the raw data into some other useful information, such as orientation.
As far as the magnetomer, we are still set to have it ready for the Q1 Firmware release.

Let me know if you have more questions on the topic!

Quentin

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I’d like to know what IMU is being used but realize you might not want to say. Just curioius…

For others, I’m updating my Wiki. Added a preliminary page on orientation of the sensors that might be of interest.

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Not sure if I can officially say the part number here, but you are always welcome to look at the board to find out :wink:

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Tried looking at the board. What I see is:

134
P1842
80?

Not sure what is at the end of the line with 80. Might be an icon rather than alphanumeric.

Web searches don’t provide any results.

Anybody else see something different than what I see?

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Rud,

I asked the team about this topic, and we decided that it would be okay to share that information.
The IMU in RVR is the BMX055.

I hope this helps!

Quentin

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Err, regarding the IMU – one clarification:

so if I use today the current Python examples to read the IMU – I get nothing until FW in Q1 is published?

Thanks,

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You do get data from the IMU, just not the magnetometer data (aka compass).

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