Gyro vs Inertial

In vex v5 whats the difference between and intertial and gyro sensor?

They’re the same picture.


They are not. The gyro sensor is a gyroscope. The inertial sensor is a gyroscope AND an accelerometer.


oh lol I always called it a gyro


There was in fact a “gyro sensor” that existed a long time ago: the Yaw Rate Gyroscope.

It is no longer is sold anymore, and in terms of accuracy, the inertial sensor is probably better. If you can get your hands on one, though, they’re still legal for use in VRC and they’re certainly still compatible with the V5 Brain.


Hi, lets not just “LOL” away passing off bad information. Better responses:

  • Sorry for the bad info, I’ve always just called it a gyro
  • TIL that the inertial sensor has gyro and an accelerometer in it
  • < silence >

Remember the first rule of answering tech questions on the forum is posting correct answers. I knew there were two sensors inside the case, and it took seconds to pull up the KB article and add that to the answer.

Doing the search is easily something that @D1Trappy could have done before posting.

Mom says “Bad answers are worse than no answer”


LOL. We always called it a gyro as well. Then we try to correct our engineering notebooks and train ourselves to say IMU or Inertial Sensor to judges. Then we realize we only use such a complex sensor that sees the world in 4 spacial dimensions just to make a semi-decent spinny turn. Like a gyro. So then it again becomes “the gyro sensor” and “the gyro turn”. Even coaches are insisting “it’s not The Gyro, it is an Inertial Measuring Unit!!” but then they ask “hey, you gonna fix that gyro turn ?”. Yup, it’s immortal. Gyro forever.

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Two things

  • only using 1/2 of the sensor is fine, but if you use the accelerometer part you can do these nice PID turns.
  • You are missing a huge chance to distance yourself from other teams by calling it “the spinny turn sensor” ie (“We use the spinny turn sensor to control our spinny turns during autonomous mode. “) Just do a replace all in your notebook and make sure you use that term in the judges interview, we eat that stuff up /s

Best wishes to your coach, we are 1/2 through the season, so the end is in sight.



One of our teams last year used the IMU as an inclinometer and also as an accelerometer to climb the platform and to predict the precise moment when to hit the brakes (motor HOLD) to prevent falling or oscillations and get a smooth balanced stop.

Yes judges eat that stuff up. However, teams need to be able to explain the big words. As a judge, it is super easy to spot when a team uses big words like Telemetry just for the sake of a good looking journal and in the hopes that the less technical judge would faint when hearing such words. I’d like to ask, are you just plastering numbers on the brain screen so it looks pretty or you actually read and use that data in any way?

On the flip side of the above, yes you are right, I absolutely cringe when teams are asked the standard, 100 years old question by judges: do you use any sensors? And they look at each other shy and kind of mumble something. Every V5 smart motor has an optical encoder inside. Back in the “cortex” days you would plop a big red quadrature encoder on your robot and every judge would faint. Now we have 8 (eight!) of them on a robot and people are silent about it.


When I’m the head judge I do a quick overview of the motors and sensors for the new judges. So they are prepared for the “umm, no sensors” and they can ask, “so you are not using the ones built into the motors?” That seems to trigger a better conversation.

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