Hackware June 2026

Retro-PC, part 3/3

whoami

• Jeroen Domburg
• Sprite_tm
• Espressif
• spritesmods.com

Last time

Last time

Need:

• LCD
• Battery
• Power management
• Buttons
• Case

Complexity!

• Series or parallel?
• Charging?
• Power path?

Old power supply

• 5V from USB-C
• 5V to 3.3V via buck
• 5V to 1.1V via buck
• 5V from USB-C to GPU/VRAM
• 5V from USB-C to USB-A

New power supply

• Vsys from battery/PMU
• Vsys to 3.3V via buck/boost
• Vsys to 1.1V via buck
• Vsys to USB-A/GPU/VRAM via boost

Main PCB runs off 3V-6V

PMU connector

• Vusb
• Vsys
• Gnd
• SCL/SDA/INT

SGM41511

• Charges 1 cell
• Vsys >= 3.5V
• Adjustable input current <=3A
• NVDC

Buttons

• D-pad, 4 buttons, 'meta buttons'
• RGB power button
• Shoulder buttons?

Power: Turn it off

• Disable unneeded rails
• Sleep I2C devices
• Deep sleep
• ...zzzz

Turn it back on?

• I2C interrupt on button / PMU event
• ULP wakes up
• ULP checks state
• Exit deep sleep
• Main code: need to start?
• Boot up: load fpga, bios, ...

Build it!

VapourDeck!

https://codeberg.org/Sprite_tm/vapourdeck

Image code, verilog, schematic, pcb