Great Scott Gadgets

open source tools for innovative people


Pseudo-Doppler Redux, ShmooCon 2018

Back in 2018 Michael Ossmann teamed up with Schuyler St. Leger at ShmooCon to present “Pseudo-Doppler Redux”; a talk about taking a modern approach to the implementation of pseudo-doppler direction finding (DF) with Software Defined Radio (SDR).

This presentation demonstrates what pseudo-doppler direction finding is and gives an example of Opera Cake usage.

We hope you enjoy watching the presentation!


Free Stuff - August 2022

The August recipient for the Great Scott Gadgets Free Stuff Program is Trevor! Trevor is working on a project called Hack365 where he is attempting to blog about one hack (or make or break or fix or learn) each day until next DEF CON. We are excited by how enthusiastic Trevor is about documentation, sharing his experiences with the community, and learning new things. One of the projects Trevor plans to take on is learning about his ceiling fan’s RF receiver, which is an excellent place to start when you are learning about RF. Trevor plans to share his progress with the DEF CON group DC612 as he progresses. We wish Trevor happy hacking and hope he continues to share what he learns so all of the community can benefit!



Free Stuff - July 2022

The July recipient for the Great Scott Gadgets Free Stuff Program is Manoj Kumar Mondal from India! Manoj requested a HackRF so he could take some security courses at his university; having a HackRF is a pre-requisite for the course. We look forward to hearing from Manoj as he progresses through the course!


Free Stuff - June 2022

The June recipient for the Great Scott Gadgets Free Stuff Program is Kyle from SkullSpace. SkullSpace is a hackerspace located in Winnipeg, Manitoba, Canada. Kyle plans to put together a group of SDR and wireless enthusiasts. This group will put on classes, host labs, and lead projects that help the community learn more about SDR and wireless. If you are ever in Winnipeg on a Tuesday evening we hope you take advantage of SkullSpace’s open night and check out their hackerspace!


FPGA Substitution on LUNA

This is a cross post from our LUNA project page on Crowd Supply.

Global supply chain issues continue to be difficult to traverse, but once in a while we do get a little bit lucky! In a previous update [1] we mentioned that Lattice had pushed out the lead time on our FPGAs for LUNA from 30 weeks to 60 weeks. Well, the expected delivery date for those FPGAs got pushed out again. Thankfully, we were able to purchase another ECP5 part for the first batch of LUNAs from an authorized Lattice distributor in a 381-ball package rather than a 256-ball package. We already have the 381-ball FPGAs in hand, so we don’t have to worry about those lead times changing again. We are still waiting on other components though, so with this FPGA substitution our estimated shipping date for LUNA will still be December 2022.

Changes to LUNA

Both FPGAs are from the same manufacturer and are part of the same line. The firmware and software we are creating will work the same regardless of which of the FPGAs is present on a given LUNA board. The primary difference impacting LUNA is that the substitute FPGA is slightly bigger than the original FPGA we had picked out. The original FPGA was 14x14 mm and the substitute FPGA is 17x17 mm. To accommodate this change in size we expect to increase the board area of LUNA to 51x51 mm instead of its original 48x48 mm.

LUNA with size increase

This change adds 297 millimetres squared of available space. 93 millimetres squared of the extra space will be taken up by the bigger FPGA which leaves 204 millimeteres squared to use. The Great Scott Gadgets team has not yet settled on what we will be doing with the extra space but we will update you all as soon as we finalize our decisions. If you would like to make requests for or share your thoughts on what to use this space for, please come discuss in our Discord server.

[1] https://www.crowdsupply.com/great-scott-gadgets/luna/updates/luna-delayed


Free Stuff - May 2022

The May recipient for the Great Scott Gadgets Free Stuff Program is C.J. who is a Broadway tour sound engineer that works backstage with wireless RF microphones. Every week the tour moves to a new location and C.J. has to re-coordinate wireless frequencies for the show. He’s hoping to use the HackRF we are sending him to improve his RF monitoring and create more precise RF layouts for the travelling shows.


Free Stuff - April 2022

The April recipient for the Great Scott Gadgets Free Stuff Program is Anmol, a high school student in India! Anmol learned about Great Scott Gadgets after watching Michael Ossmann’s video on complex numbers, which is part of his Software Defined Radio with HackRF training video series. Anmol is the IT president of their school and is excited to use the HackRF we will be sending them to share the world of Software Defined Radio with other students.


Free Stuff - March 2022

The March recipient for the Great Scott Gadgets Free Stuff Program is Katerina Autumnrain! Katerina had such an enthusiastic and detailed application to the Free Stuff Program that we just had to send her the HackRF One she requested. In her application she had this to say:

“I believe that the HackRF could enable me to open up the oft more confusing aspects of radio, particularly modulation modes like QAM and digital systems like satellites and P25/DMR. I’d also like to try and promote the higher frequencies (33cm and beyond). Once the bandwidth and frequency limitation is lifted I can more or less apply that knowledge I’d gain from those systems and make both learning experiences and some pretty neat tech for people to explore, utilize, and build themselves. I ultimately believe I could cultivate a sort of resurgence in radio geekery in my area, as it unfortunately seems to be on the downturn somewhat, and promote higher levels of curiosity.”

It’ll be really exciting to follow Katerina’s updates on her HackRF-fueled radio journey!


Free Stuff - February 2022

The February recipient for the Great Scott Gadgets Free Stuff Program is Matthew Hilts! Matthew is a student at the University of Dayton who will be spending his Spring semester learning about and using GNU Radio. To help enhance his studies we have sent Matthew a HackRF One. We look forward to hearing about what he learns!


subscribe to GSG feed