Bitcraze Forums

I am just getting this started. I have followed the tutorials on how to get it built. I wanted to jump in and use it with the iPhone app. I downloaded that, made connection, but it won't get off of the ground very well.

1) Installed all the components properly. Full Battery.
2) The LED light sequence indicates it is running properly.
3) All four motors pass the spin test on startup.
4) Green LED blinks showing bluetooth connection

However, I noticed that motors M3 and M4 do not spin at first. At 30% thrust, then they speed up to match the others. I read that this may be due to some lint in the axle or a damaged motor or a improperly installed rotor. I checked all of this, even put in a fresh motor, swapped them around, and was extremely careful in the installation. Still, these motors lag.

After I ramp up to about about 70% thrust the flie takes off and immediately spins out of control. The other motors are delivering way more power.

See video here https://youtu.be/Eto3sRt-wgE

I feel like I did most of this right. Is there any reason I should be experiencing such trouble right off the bat?

I am looking to get this thing in the air for a victorious "hello world" flight...

Any tips out there are very appreciated!

My first thought was that some of the props was placed upside down but that is clearly not the case after looking at the video.

My current guess is that it is a sensor problem (the board thinks it is tilted when it is not). You can confirm this by connecting using the cfclient and looking at the flight tab (if you have a Crazyradio). I've sent you a PM.

Ohh, and if you don't have a Crazyradio you can test by shortly apply throttle to see if all motors spin up at the same time.

Thank you for the response Tobias.

Here is a video illustrating the cfClient. I plugged in the CrazyRadio. I also have installed all the drivers successfully. I tried it with connecting the USB and without.

I saw this sensor behavior yesterday and was unsure why the flight readings were so erratic. I hope this is the information you are looking for.

Let me know what else I can do to help us diagnose the problem and move forward.

Video of cfClient and flight readings: https://youtu.be/tBNny5KwDNA?list=UUMp5 ... QEAnNHsuDw

I was able to connect correctly to the CrazyFlie after selecting the item in the connect menu.

However, I found that the sensor readings looked to be upside down. I posted another video showing these readings and the orientation. https://youtu.be/KfV0yQO72t0

Here are two pictures that illustrate the orientation more clearly. Is it possible that the CrazyFlie is upside down?

Top:

Bottom:

Yes that's it, it is upside down . Getting started instructions. Flip the motors and it should work just fine.

I feel incredibly silly. I am glad it was perhaps this simple.

I took the header mounts to be the section that carried the payload.

I also now see the "This side is up" marker... classic...

One thing I may ask, suppose I did want those headers to be on the bottom so that any circuits I mounted faced down. Could I just change the natural orientation in code or is this something that is hardwired?

And I thank you for the help once again. I look forward to flying this in the morning!

Well the LEDs look a lot cooler when it is mounted upside down and sure it is possible to change the code to have it that way. It might be a bit tricky as the sensor orientation mapping needs to be rotated 180 degrees and the motor mapping needs to be adjusted.

Excellent, I will try that when I get into the code.

Also, are there any resources for balancing it properly? I had a great deal of fun with it today but noticed it was a bit front heavy. Perhaps my battery positioning is off?

Also, I am going to go ahead and change the connections to a 2-pin JST connector type as my batter chargers are mostly that type. What is the name of the connector type it comes with for the battery?

Looking forward to more fun with this thing! Thank you again for the advice and help getting this started!

Excellent, I will try that when I get into the code.

Casey Scalf wrote:Also, are there any resources for balancing it properly? I had a great deal of fun with it today but noticed it was a bit front heavy. Perhaps my battery positioning is off?

This is a good tutorial for balancing the propellers. If you want something even more precise for that, there's this. I've only ever guessed at a balanced battery placement for the CF2. Though, I do place my battery backward. I tried to balance the CF1 once, but it was pretty hacky. If you have a constant front heavy behavior, you can correct by setting a negative trim value for the pitch. This can be done in the GUI client in fields in the "Basic Flight Control" section or alternatively, written into the firmware as part of the Crazyflie's configuration block. This is how I account for my reverse battery mount.

Casey Scalf wrote:Also, I am going to go ahead and change the connections to a 2-pin JST connector type as my batter chargers are mostly that type. What is the name of the connector type it comes with for the battery?

You can find a small list of parts here on the wiki. The battery connectors are listed there.

Casey Scalf wrote:Looking forward to more fun with this thing! Thank you again for the advice and help getting this started!

Awesome! I find just flying it more fun than hacking on it but hacking on it is pretty fun too!