Reverse Engineering Digital RF Signals the Easy Way with DSpectrum

Recently nullwolf (T.J. Acton) wrote in to let us know about a very useful wrapper for Inspectrum that he has created, called DSpectrum. Inspectrum is a Linux/Mac based tool that makes it very easy to extract a binary string from a digital transmission which can be recorded with any SDR like an RTL-SDR. DSpectrum builds on Inspectrum and further automates the reverse engineering process. He writes:

The wrapper [DSpectrum] assesses the amplitude measurements, or frequency shifts, that are reported by Inspectrum. The wrapper uses the average of the provided values as a threshold. When a cell’s value falls below the threshold, the wrapper determines that the value is a binary ‘0’, and when it is above the threshold, it records the value as a ‘1’. It then returns this raw binary data as output, in addition to the binary’s hex and ascii translations.

Another two features were included: the semi-automatic comparison of two portions of a transmission in the same file, and the semi-automatic comparison of two signals in separate files.

Nullwolf notes that with DSpectrum the time taken for him to reverse engineer signals has dropped from 1 hour down to 5 minutes in some cases.

A comparison of two binary signals in DSpectrum
A comparison of two binary signals in DSpectrum

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Anonymous

This is a sweet project, thanks for this.

nullwolf

Different people are going to have different opinions on topics like this. Mine is that tasks like coding, or report writing, are easier on Mac. Less configuration is required for my development environment, and my preferred tools just work. The right tool for the job, IMO. I use Linux for most other tasks, where it is the right tool for the job.

Jojo

Uhmmm hes using a mac :p

nullwolf

Yup. Macs are awesome thank you very much =P

ahmed

no they’re not