Thursday, August 22, 2013

Virtual Bar mode is the way to go for acro

 OpenPilot / Taulabs have another flying mode than Rate & Axis Lock that is really fun for acro.

Here is how it's documented on the wiki:

This mode is different than rate mode in that it does not try to roll at a fixed number of degrees/s for each stick position, but rather applies the sticks directly to the outputs and applies a damping from the gyros.  The end result is that you can get much more aggressive rates...

 When I've tried last year on OpenPilot code, it was really hard to tune, because of missing D term in the PID loop.
James added it on Taulabs, and now it seems better. There's still a missing I term for attitude drift, but it's already really flyable and fun to play with.

The video is a jello orgy, one of my props had 1 cm missing on one side. Only saw it at the end of the flight of course.

VBAR mode or nothing

The quad was a bit too snappy, I need to lower P termst. But still really good control.

Tuesday, August 20, 2013

Heavy Duty Tracker ( part 1 )

 Hello folks.

After the 5.8ghz little antenna tracker, It's time to build a bigger one for those heavy 1.2 antennas.

- powerfull servos for handling some weight properly
- 360° pan with wires coming on the pan axis directly
- the tracker should fit in my fpv backpack with the rest of the groundstation
- modular backpack : can be used with or without antenna tracker depending of flight plans & mobility.
- still using my Ghettostation code.
- migrate from Arduino Nano to Teensy++2

Previous Ghettostation was using Atmega328P, and was almost full.
I've added some new cool features in Ghettostation code, but more flash & ram is needed.
So I've started to port the code on Teensy++2 ( 4x more ram/flash/eeprom compared to 328P ) .
This will be developped in a separated article.

- Plywood 0.5cm 
- Teensy++2
- Bluetooth Dongle
- 900 3DR telemetry module
- 5V 5A bec
- L/C filter
- Big pan& tilt servos from Servocity. Booth use reduction, pan servo allows the wire to pass trough the central axis.


 Box is made of 0.5cm plywood I've cut with a Dremmel. 5mn epoxy was used to glue the different parts.
12V from lipo is filtered with an L/C filter to avoid servo noise coming to the video RX power. Big servo are known for generating some craps in the power lineand that's not good for the video feed.
A 5amp 5V bec will power servos / micro-controller / Bluetooth & RF modules.
Pan servo will fit inside the box.

Used some good quality gold cinch connector for video/audio, and added the 3 needed buttons ( will replace them later, they sucks ).

Now with better buttons :)

Here is what it will look once closed. You can see the wires going trought the pan axis, this will prevent wire twists with 360° rotation.

 Covered the plywood with some fake leet carbon vinyl.

Reinforced the box with aluminum  half square tube. The box is now rock solid.

Made an easy access to electronic inside, using magnets to keep it closed.

Here is what it will looks on the tripod, seems we're not ghetto anymore.

Needs to integrate the tilt axis, doing proper connections and debug the mess.
To be continued in another article.

Wednesday, August 7, 2013

Acro Flying with CC3D

 All my fpv frames are stuck on ground for now, so this week is LOS time, and acro training.

I had to test this Virtual Flybar mode in OpenPilot. CC3D is loaded with latest Taulabs code, Peabody124 added the missing D term on the Virtual Flybar PID loops, and it changes everything. Now it's far more flyable.
Looks a bit like Multiwii rate mode with high Roll/Pitch rate setting, feels slightly differently, it's hard to explain.

Tuesday, August 6, 2013

Summer lazyness

So many thing to test, not enough time for all... Stuck in a time consuming project until end September.
I've still found few spare time to fly luckily.

Met ManuxApple on my flying field the other day. He wanted to put it's keychain like on my acro quad.
Here is the result :)