Build example 2: For the advanced
This build is equivalent to the pre-built units/kits that are available in Europe, with potentially some slightly different hardware choices in the details. It will be a bit cheaper to build and of course easier to customize your purchase, use a different case, ....
- Receive ADS-B targets and forward them to the EFB of your choice
- Receive 868Mhz targets (OGN) and forward them to the EFB of your choice
- Optional: provide AHRS, barometric pressure, fan control
| Image | Item/Amount | Notes/Source |
|---|---|---|
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1xRaspberry PI | Base board that runs the software. You can either use the model 3B, 3B+ or 4B. All offer the same functionality for Stratux, but 3B draws a bit less power. You might also want to get a heatsink for the CPU as shown in the photo, but this is optional. |
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1xCase | There is a variety of ready to use cases available on amazon. We've decided to use our own 3D printed case, as it is nice and compact and has space to fit some of the common extensions (including everything that's neede for Build 3. You can get the 3D printable CAD files here https://github.com/b3nn0/stratux/tree/master/notes/case_eu. If you don't have access to a 3D printer and don't know anyone who has, you should be able to use a commercial 3D printing service. Printing this should cost you around 15-25€. Recommended print settings: PETG, bright color to reduce heat from sunlight, 0.2mm resolution. There are STL files provided for different variants. You can either print the case and the 40mm fan lid seperately, or use the combined model to print both at once. |
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1xFan with mounting screws | Any 5v fan should do. Most commercial cases will require a 30x30mm fan. Our 3d printed one can also use a 40x40mm fan, with the advantage that it provides better airflow at lower noise levels. So we recommend a 40x40mm fan and printing the respective case. |
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1xUblox 8 USB GPS | Many internal and external options available. For this built, we used a Stratux GPYes. Other GPS Chips might work aswell, but it is highly recommended to use a decent U-Blox 8 or U-Blox 9 based GPS |
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2xRTLSDR Dongle with compatible cables | Recommended: Stratux V2 SDR or Nooelec Nano 2+, but any RTLSDR dongle should do, as long as it fits in the case. They are often offered in pairs already. Do NOT get one with a Bias-Tee (e.g. Nooelec SMArTee). They consume too much power. |
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1090 MHz and 868 MHz antenna | There are many SDR + Antenna kits available that work fine. Note that these usually come with a 978 MHz antenna, instead of an 868 MHz one. In this case, you might want to consider getting an 868 MHz antenna seperately to improve reception range. The 978 one does work as well though - you can upgrade down the line if you want to. BEWARE: Make sure that your 868 MHz antenna has the correct SMA connector. There is a male and a female connector. If you put a female SMA antenna on a female SMA cable, it will NOT work. |
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Micro SD card (4Gb+) | Get a decend brand one. Quality and performance varies a lot between manufacturers, so get something decent, not the cheapest one available. They typically don't work well. |
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4x M2.5x5 and 4xM2x8 screws | The M2x8 screws may also be a bit longer, but the M2.5x5 ones may not. |
Additionally, you will need something providing 5V/2A power via a Micro USB plug (or USB-C plug if you use the Raspberry Pi 4). You can either use a cigaret lighter adapter, or a power bank, depending on your needs.
Mount the fan to the lid. We recommend to mount it as an exhaust fan so that fresh air can be sucked in from the other side of the case to cool the RTLSDR modules
Use the M2.5x5 screws to mount the RaspberryPI, and screw in the two SMA cables to the side "wings".
Try to not bend the SMA antenna cables too much. They are a bit fragile and can break.
Plug in the two RTLSDR dongles in the bottom two USB slots and connect the SMA cables to them. IMPORTANT: Your SDRs will probably be labelled "1090" and "978". The Lid of the case also has labels embossed on both sides (depending on 3D printing settings maybe a bit hard to see). Make sure you connect the 1090 SDR to the 1090 side of the case, and the 978 SDR to the 868 side of the case.
Now plug the GPS into the top-center USB port and connect the fan to the 5V headers as shown in the photo. The exact pin layout can be found here: https://www.raspberrypi.org/documentation/usage/gpio/ Connect the red cable to a "5V power" pin, the black one to a "Ground" pin.
Now connect the antennas to the appropriate sides and close the case with the M2x8 screws and you are done with the hardware
You can download the latest version of Stratux EU here: https://github.com/b3nn0/stratux/releases.
There are several guides on Youtube on how to flash the software. See e.g. here: https://www.youtube.com/watch?v=fJmMdIvb8zE.
Of course, make sure to use the image of the EU version, not the US version shown in the video.
After you have flashed the software onto the Micro SD, put it into your Stratux and you are good to go. Boot up your Stratux and it will create a WiFi hotspot called "stratux" for you. Connect to it, and then open http://192.168.10.1 in your browser to get started.
- You can add a Stratux AHRS module to get a barometric altitude (i.e. more precise relative traffic altitudes) and AHRS data (TODO: no guide yet)
- You can add a BMP280 breakout board to get barometric altitude, see here
- You can add a GY91 board to get AHRS (TODO: no guide yet)
- You can replace your GPS with a TTGO T-Beam to get transmit capabilities (See Build example 3, which does just that)
- You can add a serial adapter to connect to devices that only support serial traffic data: https://github.com/b3nn0/stratux/wiki/Stratux-Serial-output-for-EFIS's-that-support-GDL90-or-Flarm-NMEA-over-serial