IMU swap

Hello, I have the V2 board i’m almost finished. I have the MMA8452 currently installed. I’ve upgraded to the latest version which i believe does not support this IMU. I do have a GY-BNO08x and i was wondering how to mount it. Can i just connect the pins appropriately (i found a diagram on here) with loose wire, and then are guys just hot glueing the IMU to the board or is there a better way. I also have an MPU6050 and a BNO055 but i understand the o08x is better. Thank you for all the patience and help so far.

  1. short wires
  2. use an i2c extender ( PCA9615 or P82B715) so you can mount it on the roof or elsewhere with longer distances

see topic Wiring diagrams - Operations/Getting Started - AgOpenGPS

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Better IMU module :wink:

I have BNO with wires to MMA slot on PCBv2 but because box moves its unstable. Thinking about moving it outside of box and fixing it to frame.

With BNO085 because magnetometer is not used it can be placed anywhere.

Is there any benefit to putting IMU or IMU module closer to antenna and under it (to middle of tractor)?

Main advantage of IMU module is future proofing if higher IMU speed can be used?

For Chinese and other 3.3v IMU should logic level shifter be used for IMU module, on PCB its behind 330omh resistor or is it ok to connect it directly as in wiring?

Main advantage of the imu is it can figure out sidehill, and direction.

If you could turn a GPS antenna 360 degrees on a single point it would still give you the same position. You need to start moving on a vector for the gps unit to make a decision on direction.

With the imu you can turn on one point and know you are turning.

They are very complimentary to each other.

Does not matter where you put it, tilt will be the same.

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While that is true, I suspect Brian is correct that the closest you put it to the axle the better. Up on the roof it experiences a lot of acceleration which can throw off the tilt readings a bit. Several commercial units put the IMU in the globe on the roof, and they make it work, so might not be an issue.


I understand what is IMU question was more toward conflicting IMU placement and saying that IMU module is better then IMU on PCB.
(module = separate nano with IMU)

IMU can be placed anywhere but BNO08X is better closer to axel while CMPS14 is better on roof because of magnetometer.

IMU module for CMPS14 make sense so it can be placed on top of cabin away from interference.

But is there other advantage to BNO08X IMU module except

This can help in rough terrain is it that better to get box , nano , usb cable, logic level shifter and install it somewhere on axel vs just some wires to MMA slot.

Question is why go with IMU module with BNO08X vs placing it on PCB?

The only difference I see is the ease to mount it as parallel to the axle and straight in line to the direction of travel as possible, some peoples PCB enclosures are too tight so that imu cant fit it. PCB box mounting in the tractor sometimes is too curvy or cannot find a suitable flat spot. You can also zero and invert the tilt from the tablet if mounting is not truly ideal.

My ali express BNO sits on top of the pcb opto isolators with double sided tape, inside an aluminum box, no issues with it. Mounted the boxes on the floor or on a homemade bracket with Velcro.

It has to be installed kinda square to the tractor, but no need to break out alignment tools unless you really want too.