Welcome to E.E.L.D.A.R.
Electrical Engineering Laboratories for Design, Advanced Studies, and Research.
Here at the labs, we have a couple pilots.
ADS-B is an interesting system and we decided to look into the details.
We further decided to share these details with the more inquisitive technically minded pilots. That is the motivation for this effort. The customer can assemble a simple circuit board on the bench, then take a look at real time ads-b out signals on an oscilliscope(see slides below). And learn considerably more about the system.
We could write a program with a cool gui that spits out all the hex code and illustrates the fields, but we prefer the soldering up a board hands on approach.
There are four parts to this process:
1) Parsing the gps serial data for positional and velocity information. There is much other information to be transmitted such as barometric altitude, aircraft weight, performance, and other capabilities, but that’s not the point here. This is all intended to be a learning tool.
2) Post Processing – some math (CPR stuff and breaking velocities into vector components).
3) Formatting – Arranging the data into specified ES1090 frame fields and UAT978 message fields. Pulse Position Modulating the ES1090 frames and complimentary output for UAT978 messages.
4) Up Converting – ASK for ES1090 and CPFSK for UAT978.
For now we are offering what we call the Base Band Gererator kit. It performs steps 1, 2, and 3. See kit information below.
We are putting the up converter on an IC now and developing art work for the board. With this, an SDR, and open source software like Dump1090 or RTL1090, you can drive around and watch the position, speed, and heading numbers change in real time on your laptop.
That kit will be coming soon.
We are also looking for a software guy to port all this code over to an ARM micro. When that is complete, the ARM, together with the front end IC, should constitute the world’s tiniest and lightest ads-b out transmitter. Simply bragging rights for E.E.L.D.A.R.
**** IMPORTANT ****
None of this information, hardware, or software is certified or approved by the FAA for use in any aspect of general aviation. The up converters are micro power. Not effective beyond immediate bench type distances. It is strictly a hobby type project to learn more about ADS-B OUT.
Contact information will be posted August 2021.