Latest: Meet Project Patchouli, An Open-source Drawing Tablet Project To...

For something intended to mimic good old pencil and paper, drawing tablets and the tech behind them are surprisingly complicated. If you fancy a crash course in how they work and want to build your own from scratch, I have the open-source project for you.

Project Patchouli from designer Yukidama is a project to "build your own EMR tablet from scratch". As helpfully laid out in Yukidama's YouTube video, an EMR tablet is one that uses Electromagnetic Resonance that sends a signal to a tablet, which is then translated by the tablet. It's a quick and responsive bit of technology, but different pen vendors work off different frequencies, which can impact compatibility.

The video shows how electromagnetic pencils have coils and capacitors near the tip; a test board picks up that frequency and uses a signal amplifier to send that information to a computer. With an oscilloscope, Yukidama measures the frequency of each pencil as it touches the board, and then that frequency as they press harder. Two different pens register two different frequencies.

This project uses a smart array of coils in the tablet itself, making it "compatible with most commercial pens from different vendors, offering an ultra-low-latency pen input experience for your customized hardware projects."

Admittedly, due to the high level of complexity in the build, some of this project goes over my head, but the gitlab source gives the firmware and hardware designs you need to build it. It also provides helpful graphs and some extra pictures in the 'docs' section.

Much of the hardware blueprints are in CAD files, which means (for most) having to send those files off to get created by a circuit board manufacturer. A project like this won't be done on a whim, but it's still rather impressive.

Over on the Project Patchouli Discord, Yukidama has said that they are looking into documentation so that the non-initiated can also replicate the project and has said, "Please let me know if there's something you want to know in particular, so I can include them in the guide." Though I'm tempted to say 'well, all of it', I do think the YouTube video does a good job at explaining the background of EMR tech and why artists use EMR tablets.

Keep up to date with the most important stories and the best deals, as picked by the PC Gamer team.

In a sense, one could look at this more as a proof of concept than a replacement for a drawing tablet. Modern drawing tablets will have all kinds of neat software and har

Source: PC Gamer