Gromit-MPX

Posted on 2025-02-10 [Monday] by Jay Jay

Gromit-MPX is an on-screen annotation tool that works with any Unix desktop environment under X11 as well as Wayland.

Arduino Keyboard library not working on Debian KDE

Posted on 2025-02-10 [Monday] by Jay Jay

Man, I just spent quite a bit of time diagnosing this particular issue.

The problem was that my Symbol Keyboard stopped working. This is a USB keyboard I made from an Arduino Leonardo. The touch screen was working okay, but the keypresses weren’t being delivered over USB.

Long story short, the 7-port USB 3.0 hub attached to my workstation needed rebooting! I disconnected the power supply and disconnected the upstream USB cable to remove both sources of power, then when I reconnected everything my stuff started working again, including my symbol keyboard.

Lesson learned: if you’re debugging a USB device failure try plugging the device directly into the host to avoid any potential issues caused by your hub(s).

It was lucky I had a spare 104-key USB keyboard in the cupboard because I needed one while diagnosing this issue (the Windows box I was using only has a tenkeyless 87-key keyboard plugged into it but the Windows alt-key codes require use of the number pad).

The latest incarnation of my symbol keyboard looks like this:

CSS library based on Counter Strike 1.6 UI

Posted on 2025-01-27 [Monday] by Jay Jay

This turned up in my feed today: CSS library based on Counter Strike 1.6 UI. I was particularly interested in how they implemented the tab panels.

JTAG ‘Hacking’ the Original Xbox in 2023

Posted on 2025-01-20 [Monday] by Jay Jay

This turned up on hacker news today: JTAG ‘Hacking’ the Original Xbox in 2023 – Using Intel CPU JTAG to dump the secret bootrom in Microsoft’s original Xbox. There’s some info being collected on github: github.com/Necrosys/x86-JTAG-Information.

Time and Space Complexity

Posted on 2025-01-16 [Thursday] by Jay Jay

This is good: Time and Space Complexity. If I find myself needing to explain algorithmic complexity to someone I will refer them to this.

Interlude #11: Playing with WeAct Studio Epaper Modules on ESP32-C3 MCU | In The Lab With Jay Jay

Posted on 2025-01-16 [Thursday] by Jay Jay

This post is part of my video blog and you can find more information about this video over here.

You can support this channel on Patreon: patreon.com/JohnElliotV

In this video we play around with the 2.13″ and 2.9″ WeAct Studio Epaper Modules available here: WeAct 2.9” 2.13″ 2.9 2.13 Inch Epaper Module E-paper E-Ink EInk Display Screen SPI Black-White Black-White-Red.

As I mention in the video I was having a hard time getting good solder joints from my Horusdy Soldering Station. This was annoying me so much that I went and purchased a new soldering iron! My new iron is an Metcal PS-900 Soldering Station and I love it! This is what a soldering iron should be!

We use the Arduino IDE and the sample code from WeAct Studio but we don’t successfully load content into our Epaper Module.

We use the Rigol MSO5074 Mixed Signal Oscilloscope to and the Rigol PLA2216 Logic Probe to wire up a Logic Analyzer to instrument out circuit, but we don’t follow through with that in the end. We run out of time. We will try again another day.

Thanks very much for watching! And please remember to hit like and subscribe! :)

Following is a product I use picked at random from my collection which may appear in my videos. Clicking through on this to find and click on the green affiliate links before purchasing from eBay or AliExpress is a great way to support the channel at no cost to you. Thanks!

Yum Cha 58-pcs Stainless Steel Thread Pitch Gauge