A bit of an update

August 2013

A lot of things have happened. Shortly: I added several modules to the source, notably modules for XBee and GPS. I’ve set up wireless link between two XEFIS instances, and could read current altitude with help of a BMP085 pressure sensor. ;-) Things are slowly pushed forward, though I had some hard time with DN2800MT motherboard and Cedarview graphics drivers. Seriously – don’t buy it. Nevertheless, here’s what my groundstation looks like now. :-)

IMG_9207
XEFIS running on Archlinux, DN2800MT motherboard (don’t use it) and cheap Chinese flat panel.

More or less…

June 2013

…it will look like this:

IMG_8697

Things to be done:

  • Reinforce panels, because they’re too sloppy.
  • Make PCBs to hold buttons and 7-segment displays under the main LCD screen.

Instruments

May 2013

Long time no see!

I’ve never posted any screenshots of the software I’m preparing for the station, so here is one. Its design is based on Boeing’s 787 glass cockpit. Recent additions include shadows/outlines under features and text, and font that resembles more the one used in Boeing’s aricraft. And this is, more or less, what I’ll see on my groundstation’s LCD screen.

Instruments panel

Did I forget about something?

April 2013

This is probably the final design of top and bottom panels of my groundstation. And this is the first ever CAD design I created, heh.

One funny thing: when I was searching for a victim that would cut the front panels for me, I found a rc-model hobby shop which offered a CNC service (yay!), but apparently only accepted .CDR (Corel Draw) files. They claimed they couldn’t open DXFs. WAT! That’s where I started to doubt that they were professionals. ;-)

groundstation-panel-top
groundstation-panel-bottom

HOLTEK

March 2013

Just received a package from China with a set of Holtek HT16K33 chips. Will use them to control switches and 7-segment displays over I²C. Awesome little things.

IMG_8691

Hardware

March 2013

Ok, some more hardware plans. Initially I thought that Raspberry Pi would be a good choice for a groundstation. But since XEFIS runs on Qt5 and does a lot of drawing, it needs more capable CPU than some slow ARM on Raspberry Pi. GPU won’t cut it, because I’m already using Qt’s QPainter and I’m not willing to rewrite everything to OpenGL. So, Rasperry runs XEFIS rather slowly – 1 fps with EFIS and NAV displays – and doesn’t meet my needs. ;-) So I bought a mini-ITX motherboard with dual-core 1.86 GHz Atom. And then added threaded painting to XEFIS. Works fine now. 15-20 fps is OK, and it will be even more if I hide ND, which I won’t really need for FPV flying (or at least I won’t need all VORs, DMEs, airports, etc displayed).

Raspberry Pi will find its place inside the model and will run XEFIS, too, but without any “displays” – just modules responsible for automated flight, communication, etc. They are not very CPU-demanding.

There’s also a LCD panel, Chinese LG substitute, that waits to be connected to the motherboard. I had to order LVDS connector to the motherboard from China, since obviously Intel had to put a connector that’s impossible to buy in normal electronics store.

Raspberry Pi + GPS receiver, Intel DN2800MT Atom motherboard

Raspberry Pi + GPS receiver, Intel DN2800MT Atom motherboard

A brief list of what I have already:

  • Motherboard
  • LCD panel
  • Noname 16 GB SSD hard drive (Archlinux installed)
  • Knobs, switches, interfaces, 7-segment displays
  • Small TV display
  • Casing
  • Barometric pressure sensor – for airport pressure reference

Things related to the plane:

  • Raspberry Pi
  • Adafruit I²C-PWM controller (for servos)
  • GPS module
  • Barometric pressure sensor

I still need:

  • CNC-cut panels
  • MAX7219 chips for controlling switches and 7-segment displays
  • At least three 5 Ah 3-cell LiPo batteries
  • Communications modules – controlling and telemetry

And for the plane:

  • Airframe
  • IMU with compass
  • Airspeed sensor
  • Current and voltage sensor
  • Transceiver for plane control and telemetry
  • Pan-tilt mechanism for camera
  • Backup camera
  • Servos, motor, etc.

Maybe I’ll try to hack EagleTree Airspeed sensor, will see. They don’t have any documentation, so they’re basically useless if not used with other EagleTree modules, unless someone tries to figure out their communication.

Since I don’t plan to put radio modules inside my groundstation, I’m not worried about them now. Let’s say that radios will be a separate station.

Casing

March 2013

Tool cases

I bought an “aluminium” toolcase for the station. When it arrived I’ve quickly realized that it’s too big for my needs. And because it’s not 100% aluminium (more like 5%), it’s not rigid enough.

So I bought another, smaller one. So simple. First one will carry other equipment (batteries, cables, antennas, etc).

Maker: Allit, type: Toolcase-18.

I had a dream

March 2013

A dream of nice ground station. I saw quite vividly that it had 787-like glass cockpit, could be controlled with regular USB joystick/throttle, and was easy and quick to set up.

So I thought: I need one!

My old, primitive 5.8 GHz groundstation
My old, primitive 5.8 GHz groundstation