Transceiver example?

[git-artes]

Hi,
This is a very interesting project, and I've been wanting to test it for use in classroom as a demo. However, I cannot seem to make a simulated transceiver work. I've tried making a new flowgraph that includes both the transmitter and receiver, but I cannot get the decoder block to produce anything useful. Do you have such an example?
thanks!

[cpoore1]

It does take some extra work to get it working in a file. There are a few problems when you go to combine them:

1. First, it uses tags at the start of every message because it's meant for a UHD sink that handles them pretty well. It doesn't work well for other radios that don't utilize those tag. I should change it to be continuous so more people can use it. If you add samples before each message with something like the Burst Shaper block, add noise, and drop the tags, it will look more like a real signal with silence between each message.
2. The receiver needs those breaks because it detects the edges and tags them. The decoder looks for those tags.
3. The threshold block needs to be adjusted to something like 0 and 0 for the low and high when looking at the perfect FM signal. Then it should print the 1's and 0's properly and be recognized by the decoder. The decoded message will then be printed at the bottom. It should mostly match up to the input data. The pressure has quantization error from the formula but it is close.

It only does the one TPMS format mentioned in the README (there are a lot of different types). I could add more if people want to see it. I could build new types blindly with the information pulled from rtl_433.

I assembled a bunch of example flow graphs using these TPMS signals for classroom lessons if you're interested. I give people the option of using FISSURE and GNU Radio to do the same RF reverse engineering steps.

You can find a couple extra IQ files to work with when you download FISSURE (https://github.com/ainfosec/FISSURE). I think there are two files in the Archive folder taken from a car. There's only one file in this repo under /examples.

Try it out and let me know if you get it working. Tell your friends about FISSURE and star the repo.

tpms_transceiver.zip

[git-artes]

Worked like a charm! Thanks! Didn't know about the Burst Shaper block, I was trying to add zeros by using a stream mux and computing the size of each packet, maybe that was the problem.

I'll be more than interested to take a look at those flowgraphs with TPMS signals. I try to include as many demos as possible in class, and for binary modulation I'm currently using RDS (through gr-rds), but the technology is somewhat "old fashion" and students cannot really relate.

Regarding FISSURE, I've seen it and was impressed by it. I'll sure star the repos. BTW, is there any contrib guidelines? I mean, if I can get group of students to do their end-of-degree project in FISSURE, what would be a nice contribution?

thanks again!

[cpoore1]

Excellent. Send me an email through the FISSURE contact info at the bottom of the page and I'll give you some material. You can decide if any of it is useful to you. I'm updating the FISSURE README, hopefully by the end of next week. It will have more white papers on specific subjects like:

• General Overview (Short)
• Technical Details & Architecture (Long)
• Training & Education
• Counter UAS
• Maritime
• Perimeter Infrastructure Defense
• TAK & Mobile Integration
• UAS Payload & Aerial Ops
• Vehicle & Mobility Systems

From those you can see where we're going with this and what's missing. I've also created an expanded roadmap with interactive diagrams that will list the goals we're trying to achieve and where our progress is. It will be accessible from the README once uploaded. I can also point you to different areas of interest that aren't actively being developed that could use attention.

I'd love for more students, projects, and lessons to use FISSURE. We've had student projects in the past help with things like testing and integrating new hardware types into FISSURE or recording and replaying signals with something like a PlutoSDR to interact with RF devices. Any new features, third-party software, use cases, testimonials, or discovered bugs are helpful. Anyone is welcome to contribute to FISSURE from an individual level up to whole organizations.