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Real hacking is back

There was once a time when "hacking" was a good thing.

To "hack" something had no negative connotations, it was simply a way of getting more out of less or turning a mundane device into a much better one through some clever engineering.

More often than not, these were hardware-based hacks revolving around making changes to the physical components of a device, rather than simply changing the software or firmware.

If someone was a "hacker" then they were looked up to as generally being a person with above-average intelligence and problem-solving skills.

Sadly, today the title "hacker" more often refers to some snotty-nosed script-kiddy downloading malware from the internet and inflicting it on unsuspecting innocents.

However, recently I've been impressed to see that the spirit of the old-school original hacker has been revived, somewhat.

In this case it's a case of very smart cookies repurposing one of the world's most popular microprocessors/microcontrollers to do something it was never designed to do.

Anyone who's dabbled to any extent in the microcontroller world of late will know about the ESP32 family of devices.

These are exceptionally capable chips that pack a lot of power and functionality into a single device. More often than not they're purchased as a module, complete with wifi antenna or connector and with much of the I/O wired up to castelated pads or pins for easy integration into projects.

Two separate hackers seem to have discovered ways to "repurpose" the wifi section of some ESP32 chips into software defined radio (SDR) receivers.

Normally this part of the microcontroller is treated as a functional block that simply acts as circuitry to provide connectivity with any other wifi device. However, the discoveries by these guys has enabled that circuitry to actually function as the front end of what could be a quite useful general purpose SDR on both the 2.4GHz and 5GHz bands.

As a drone flyer, I was pretty impressed to see that one of the hacks results in the ability to create an analog FPV video receiver using little more than the ESP32 itself and a simple resistor-based DAC (digital to analog converter).

This is actually pretty cool.

Other uses for these hacks include the creation of el-cheapo spectrum analyzers on the 2.4GHz and 5GHz bandes as well as traditional SDR setups with those cool waterfall displays.

The hacks work by using an undocumented debug capability that allows direct access to signals that are normally internal to the wifi circuitry. This lets the raw I/Q signals to be extracted before they're sent to the internal wifi modem. This data can then be streamed via the USB port to a more powerful computer for decoding or, for more simple tasks, actually processed by the CPU cores within the ESP32 itself.

Unless you're somewhat technically literate this probably all sounds like Greek but the TLDR is that some people found clever ways to turn a popular chip into something it was never designed to be and in doing so created a whole new application for it.

How cool is that?

Carpe Diem folks!

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