HefnyCopter has brought altitude hold capabilities to the KK2.0 flight controller using an HC-SR04 Sonar! As you can see from the video above, it appears to do an amazing job. There are limitations to using a sonar for altitude hold. It only works up to 4 meters and it maintains altitude with the terrain. It is more common to use a barometer for altitude hold. It looks like it will be fun to experiment with this firmware realizing it is still in the process of being developed.
HefnyCopter is firmware written for the KK2.0 by MHefny as an alternative to the standard firmware that comes loaded on the board. It can be easily loaded using the LazyZero KKMulticopter Flashtool and a USBasp AVR Programming Device for ATMEL proccessors. Here are the pins to connect the USBasp to the KK2.0.
I have yet to try this firmware, but ordered an HC-SR04 Sonar off ebay that ships from the USA. It was under five bucks and should be here in a few days. I am planning on giving it a try and doing a post on the detailed steps I follow in my attempt to implement altitude hold.
HefnyCopter has lots of other cool features and I am really excited about giving it a try. Here is a list of features that are also listed on the HefnyCopter website:
- Sonar altitude hold
- Buddy mode allows two tx/rx for training a friend on a quadcopter(click here to see a video)
- Switch quadcopter mode from +Quad to X-Quad without changing board orientation
- Fewer wires
- New stabilization system
- Auto disarming feature
- Buzzer to find a lost quadcopter
- Transmitter sticks can be used to control lcd buttons