Quote:
Originally Posted by Gdeaver
For a gyro-IMU-AHRS solution we used the NavX MXP in 2015. It has worked for us, but we have had problems. We bought 2 boards. One has failed, will not initialize. We have had problems with the IO ports. Some are unusable and others are not reliable. We mounted our Roborio vertical. This forced us to use a cable between the Rio and the Navx. We use the NavX for 2 tasks. The NavX tells us which way our robot is pointing. (not which way our robot is moving). Second, it tells us if the robot is tilting. We fell over 3 times in competitions this year. We use the navx to stop us from tipping. If the the angle of tilt goes beyond x degrees, reverse the drive motors. It works.
For 2016 we are looking for a better IMU. We recently purchased a Arduino Shield with a Bosch BMO055 orientation sensor. It has a 3 axis accelerometer, gyro and magnetometer. Plus a Arm cortex M0 core running fusion code. Easy set up. Initialize the I2C port, write to a few registers and its running. We bought the Arduino shield for testing. Will use the Adafruit board on the robot if we go with it. Only have 1 hour of testing. Gyro, accelerometer fusion looks rock solid. Add in the mag and it is not good. Interesting is the linear acceleration output. It's a little noisy but with a little clean up could give direction of motion. Not suitable for distance. Better than the Invensense outputs. Looks good but you never know until it's on the robot.
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Please do send in the board that won't initialize, we'll get it replaced for you. Just send it and return address info to:
Kauai Labs
2371E Nimualu Road
Lihue, HI 96766
The updated firmware (it'll be loaded on your replacement board) includes the new Omnimount feature which enables vertical, horizontal and upside-down mounting, and has some reliability improvements. The addressing of the Digital IO pins has given folks some trouble, it has gaps in the address space, documented on
this page. If you have details on a port that isn't working, please send that information along, too.
We're getting ready also to release new Java/C++ Libaries w/SPI support at 2Mhz, with that enhancement the measurement latencies and RoboRIO CPU usage are very low.
Which board are you are using w/the Bosch sensor? I'd like to compare the linear acceleration values it generates with those from the navX MXP. I'd agree Invensense has some work to do on accelerometer noise levels on the MPU-9250, but wasn't aware the Bosch sensor specs were that much better, am very interested to hear your findings.
Thanks,
- scott