Hi

I’m Evan. I do nerd things: software engineering (professionally) and electronics (amateurly). I am interested in robotics, digital signal processing, Bayesian inference, (human) language learning, and community emergency preparedness.

Blog posts

• 2024/03/05 Pipad: Identifying the ambient light sensor
• 2024/01/21 Pipad: Audio codec: ground-centered mode, BCLK, headset detection
• 2023/12/29 Pipad: It’s a tablet! (Rev2 PCB testing)
• 2023/10/04 Pipad: NVMe, HDQ, SDIO, and curvy PCB traces
• 2023/01/23 Pipad: Debugging the power button
• 2022/10/21 Pipad: Attempting to tune the touchscreen controller
• 2022/10/18 Pipad: Trying my hand at driver development
• 2022/10/16 Pipad: Backlight flickering investigation + device tree overlay for the battery charger.
• 2022/10/15 Pipad: Starting to look like a tablet
• 2022/10/07 Pipad: The LCD works!
• 2022/07/04 Pipad: Some progress on the LCD
• 2022/07/04 Pipad: Getting the GT9110 touchscreen controller working
• 2022/06/29 Pipad: Real-time clock: It’s nice when something is easy.
• 2022/06/26 Pipad: Figuring out why the CM4 wouldn’t boot when attached to my board
• 2022/06/14 Pipad: CM4 carrier board: chip shortage pain, bodges, silly mistakes, and tragedy.
• 2022/01/26 Pipad: RPi CM4 and Radxa CM3 versions of the board
• 2022/01/15 Absurdle Hard-Mode High Score
• 2021/08/23 Pipad: Colors! (sn65dsi83 test pattern)
• 2021/08/18 Pipad: Using ftrace to debug device tree problems
• 2021/07/10 Pipad: First light: testing and fixing the backlight controller
• 2021/07/08 Pipad: Power supply testing, part 2
• 2021/07/06 Pipad: Power supply testing
• 2021/03/22 Pipad: Attempting to write a device tree overlay for the soundcard
• 2021/03/09 Pipad: Finally, things to solder!
• 2021/03/02 Pipad: Video output research
• 2021/02/25 Pipad: A more reasonable touchscreen controller IC
• 2021/02/23 Pipad: First prototype of soundcard, some breakout boards, 30-pin connector decision
• 2021/02/12 Pipad: The beginnings of the soundcard
• 2021/02/03 Pipad: The big scary touchscreen connectors
• 2020/10/12 Designing a PCB in EasyEDA and getting it assembled by JLCPCB