Sensor Bias...place on a level surface.

The Editor · Mar 31, 2015

RGD said:
Do you know what IMU stands for.

IMU stands for inertial measurement unit - it is basically a solid state device that houses a 3 dimensional gyro and a magnetometer or compass unit.
Your mod values should be 0.0, .99-1.01 and compass mod should be around 1500.

Hope that helps.

devin120 · Oct 22, 2015

Like this doctor?

Amazing first post on Inspired huh...

The Editor · Oct 22, 2015

devin120 said:
Like this doctor?

Amazing first post on Inspired huh...

Correct - Welcome to Inspirepilots.

inspire909 · Oct 23, 2015

are you moving the inspire after start up ?? if so that could be the problem ..if you haven't been checking you mod values in your preflight check consider yourself lucky!! always always check those mod numbers before putting your $3000 bird in the air
if you print out the inspire pdf manual you'll find a huge amount of great info. take you time and read it i guarantee theres some stuff in there that will make you go ohhhhhhh!!!
(no sarcasm implied)

The Editor · Oct 23, 2015

inspire909 said:
are you moving the inspire after start up ?? if so that could be the problem ..if you haven't been checking you mod values in your preflight check consider yourself lucky!! always always check those mod numbers before putting your $3000 bird in the air
if you print out the inspire pdf manual you'll find a huge amount of great info. take you time and read it i guarantee theres some stuff in there that will make you go ohhhhhhh!!!
(no sarcasm implied)

Who was that aimed at? If it was devin120 his mod values are just about spot on.

inspire909 · Oct 23, 2015

It was for the up he said in one of his posts he constantly has to move his inspire I'm wondering if he does this while the inspire us on

The Editor said:
Who was that aimed at? If it was devin120 his mod values are just about spot on.

devin120 · Oct 24, 2015

TX on
RX on (Inspire)
Calibrate compass or imu if needed
RESTART rx (Inspire)
Let all 5 million gyros calibrate. go fly.

Maybe if you go straight from compass calibrate to fly it retards the gyro vs compass deviation and all that science talk. You know what I mean?

Theirs so many systems initializing and calibrating on startup spinning it around and trying to place it level again would be an issue.

Although I doubt you would do that.

SultanGris · Oct 24, 2015

shouldnt need a level surface to take off unless something has changed in newer firmware, i use older firmware and take off from slanted surfaces all the time without issue, such as the bed cover of my truck when parked on the side of the highway at a slant. no problems ever.

The Editor · Oct 24, 2015

devin120 said:
TX on
RX on (Inspire)
Calibrate compass or imu if needed
RESTART rx (Inspire)
Let all 5 million gyros calibrate. go fly.

Maybe if you go straight from compass calibrate to fly it retards the gyro vs compass deviation and all that science talk. You know what I mean?

Theirs so many systems initializing and calibrating on startup spinning it around and trying to place it level again would be an issue.

Although I doubt you would do that.

It is not advisable to calibrate the compass every time you fly.
There are many threads on the forum and my views on this.
Do a search and you will see why compass cal every flight can actually be a bad thing.
More important than anything is checking mod values.

devin120 · Oct 24, 2015

Advice from someone more experienced. I shall follow your advice. Thanks.

Stupid question. When i do my compass calibration however (Today was my first inspire flight) Do you or can you just keep spinning it on its axis or do you really try to do solely a full 360 and stop...... ?

It's probably in the manual I should search. It was alot of info to take in! First multirotor flight on an inspire today. Went well!

SultanGris · Oct 24, 2015

I believe you have to make the full rotation, lights will flash or something when you do it correctly to inform you to move on to the next step. I forget exactly, haven't calibrated mine in about 8 months, haha

The Editor · Oct 25, 2015

devin120 said:
Advice from someone more experienced. I shall follow your advice. Thanks.

Stupid question. When i do my compass calibration however (Today was my first inspire flight) Do you or can you just keep spinning it on its axis or do you really try to do solely a full 360 and stop...... ?

It's probably in the manual I should search. It was alot of info to take in! First multirotor flight on an inspire today. Went well!

Yup, as Sultangris commented you must do a FULL 360degree rotation until the tail light changes. In actual fact it is slightly more than 360 ( you have to go right round and slight past your starting point and the led will change). Then do the same nose down and you're good to go.
Do always, always check your mod values though before you take off.
A well calibrated compass should have mode values fluctuating around 1500. In practice anything between 1400-1600 is 'safe' though.
Take the Inspire off, climb to around 20 feet, hands off sticks and in GPS mode it should hold position extremely well. If it doesn't, something isn't right you should land and investigate.