StratuxWhat's inside a Stratux
Stratux is built from off-the-shelf parts, so every part can be replaced on its own.
The parts
| Part | What it does |
|---|---|
| Raspberry Pi | The computer that runs the Stratux software from a microSD card |
| 1090 MHz radio | Receives 1090ES traffic, broadcast directly by aircraft worldwide |
| 978 MHz radio | Receives UAT traffic and FIS-B weather (US and Canada) |
| GPS | A u-blox USB GPS with WAAS, which gives your EFB its position |
| AHRS board (optional) | Attitude sensors for synthetic vision, plus the fan controller |
| Fan | Temperature-controlled; turns on at about 55 °C |
Which Raspberry Pi?
| Model | Verdict |
|---|---|
| Pi 3B+ / 3B | The standard choice: most tested, runs cool |
| Pi 4 | Works, but runs hotter and draws more power for no benefit |
| Pi Zero 2 W | Tight on performance |
| Pi 5 | Not recommended (power demands, no fan control) |
Stratux isn't limited by the processor; the radios do the heavy lifting. A Pi 3B+ is plenty.
The radios
- 1090 MHz uses an RTL-SDR (software-defined radio).
- 978 MHz on current builds uses a dedicated UAT radio based on a TI CC1310 chip, not an RTL-SDR. It connects to its antenna port through a small, fragile u.FL pigtail; a broken pigtail is a common and cheap fix. It's a UAT receiver only and can't receive FLARM.
If you're choosing radios for a build, the original Stratux project's low-power radio comparison covers heat and noise.
Power
Stratux runs on 5 V USB and needs at least 2 A. See Power and status lights.
The HDMI and audio ports
They're part of the Raspberry Pi and aren't used in normal operation. Developers can plug in a monitor for Linux access; pilots can ignore them.
Antennas
Use the right antenna on each port and hand-tighten only. See Stratux antennas.