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Permalink Reply by 3D Robotics Tech Support on November 23, 2011 at 3:19pm

Hi Rapi,

The ArduIMU V3 is not a replacement for the ArduPilot Mega IMU shield or the ATMega boards. You can find a full list of features on each board in the product descriptions online, but to summarize: the V3 lacks many of the features that are included on the oilpan, such as the USB connector, the relay, dip switch, slide switch, pressure sensor, and many of the ports (for telemetry, airspeed sensor, etc.) to name a few. You will not need the ArduIMU V3 in addition to the oilpan if you are looking to use the ArduPilot Mega codes, and currently, the ArduPilot Mega codes work with the APM+IMU setup.

From the product page for the V3: "ArduIMU is not an Autopilot it's just an orientation solution (the heart of an Autopilot) and can be used on anything you want to know it's orientation in respect to the ground, like boats, cars, rockets or even your dog. To know more about IMU's read here.

ArduIMU V3 features the new MPU-6000, that includes 3 axis gyros & accells built-in and process everything internally that is some kind of dual core power (24-bits ADC sampling and sensor fusion is handled inside the MPU), the latest 3 axis I2C magnetometer HMC-5883L and the classic but very robust Arduino Atmega328 running at 16Mhz"

I hope this helps!

 

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Permalink Reply by Gerry Lichter on November 25, 2011 at 11:23am

My impression of the distinction:

The APM/Oil Pan are a highly integrated and plug and play system. The ArduIMU V3 is an AHRS/IMU which should be thought of as a more modular and "platform agnostic" sensor package. Fewer features than the oil pan, but compatible with the ArduIMU V2 pinout. This makes it a potential upgrade for legacy hardware and offers a product which doesn't include hardware that may not be needed or desired for your application.

 

The ArduIMU V3 is one of the first boards on the market which uses the MPU-6000 chip from InvenSense. This chip is a combination MCU, 3 axis Accelerometer, & 3 axis Gyroscope. The on-board "MPU" handles the InvenSense "Sensor Fusion" equivalent of the Ardupilot project's DCM library. This should in theory free up resources for the onboard Atmega328 which was previously used on the ArduIMU V2 to handle the DCM.

 

For more info, this is the video which got me so excited about this board:

http://www.youtube.com/watch?v=C7JQ7Rpwn2k

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Permalink Reply by Evan Evans on December 11, 2011 at 5:41am

From Evan Evans

What I would like to know is whether this V3 Arduimu board requires special software to run it or whether the the Arduimu 1.8.2 will work.

The fact that it is so different to the Arduimu V2 rather indicates that it will require it own program but I have not been able to find it at this stage.

It is ok to say it is pin compatible to V2 but what about software?

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Permalink Reply by Tim - Arduino for Visual Studio on December 11, 2011 at 8:17am

it requires new firmware, 1.8.2 will not work

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Permalink Reply by Evan Evans on December 11, 2011 at 5:59pm

That is what I expected but where do we get it from?

I have ordered one of these boards but it will be useless without firmware, I am not a programmer so I will not be able to write my own.

Sorry I just found the thread on the Ardupilot Legacy forum that advances my knowledge somewhat. I will follow it on there.

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Permalink Reply by Gerry Lichter on December 11, 2011 at 9:49pm

I'm in the same boat. My solution is to wait until a programmer writes the new code & try to learn to program in the mean time.

The problem is actually pretty trivial.

The experimental firmware is everything you need except you have a series of "int" variables which you need to print over serial in the same structure used to print the same "int" variables in the previous ArduIMU V2 Flat code. I expect it would take fewer than 20 lines of code to make the conversion.

I got my money's worth from the hardware, but I have confidence that the software isn't far off.

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Permalink Reply by Art Whaley on December 24, 2011 at 10:06pm

Seeking a little clarification...  

Once the IMU V3 firmware is finished and the code released (I read somewhere that should happen next month?)

Will it be possible to plug the V3 IMU into the Ardupilot Mega 2.0 board and have a functional autopilot?  I recognize that there will be missing features that the oilpan offered, but will it fly?  And will it fly with arduplane 2.7 code or will the arduplane code need to be modified to work with the V3 IMU?

I'm on the fence between picking up the ardupilot mega 2.0, or the ardupilot mega 1 with the v3 IMU.  I've already got a GPS module, and I like the modularity of going with the mega 1 and the v3 imu, both because I could update IMUs in the future, and because I like to tinker with all sorts of projects and can see both times when I might use the ardupilot board without the imu for projects, and times when I might want to use the imu with other processors as well. 

But that flexibility is secondary, of course, to whether or not it works for the intended purpose at the moment, which is getting a drone in the air!  :)  Will I be cursing myself for trying to hack the two together and make it fly instead of just buying the ardupilot 2.0 and having a ready-made solution?  I don't mind SOME tinkering but I don't want to have to completely recode either device!

Art

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3D RoboticsPermalink Reply by Chris Anderson on December 24, 2011 at 11:15pm

Art: APM2 has its own IMU built in--it's a functioning autopilot right out of the box. There's no need for (or connection to) ArduIMU, which is a stand-alone IMU for tinkering with.

There will be a version of it without the GPS if you'd like, but given how cheap it is, why not go with the one that has the GPS built-in and is guaranteed to work?

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Permalink Reply by Art Whaley on December 25, 2011 at 12:24am

Sorry for not being clear -  I understand that APM2 is a complete solution, my question was really how far is APM1 plus IMUv3 from being a complete solution as well?  Would that combination work 'out of the box' with the stock code?

 The only reason for going that direction is that I could see me wanting to use the APM1 board as a standalone arduino with servo control sometime in the future, without an IMU for a stationary project... or use the IMUv3 board with a propeller MCU, for example...  but at the MOMENT I want to use them together for a UAV project...  so if APM1 plus the IMUv3 will work as a complete unit without needing extra parts or a ton of extra code, that route would give me a UAV now, and give me more flexibility down the line on future projects...  if that's not a good combination for whatever reason... then I'll probably just buy the APM2 and if I re-purpose it later, it'll be a stationary project with an unused IMU...  or an IMU with one heck of an overpowered MCU in the middle collating the sensor data and passing it out the serial port...

Thanks for all the help!

Art

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3D RoboticsPermalink Reply by Chris Anderson on December 25, 2011 at 9:20am

Oh, APM1, not APM2.  Yes, technically you could combine APM1 and ArduIMU 3 to make a complete Autopiliot, but it would take months of coding work with an expert coder. I wouldn't even know how to begin. It absolutely would not work "out of the box". 

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