Most of the project is in the setup
The Pocket Pi repository mostly documents the hardware and boot setup. The operating system, display driver, controls, and power monitoring each do one job. That makes problems much easier to isolate when the tiny screen stays stubbornly black.
The original guide targets Raspberry Pi OS Legacy, Bullseye 32-bit. Keep that in mind when using its boot files and framebuffer instructions. I haven't tested the same steps against every newer Raspberry Pi OS release, so this page doesn't pretend otherwise.
Get remote access before touching the display
The repository's bootfs/ folder has display and GPIO settings, a command line with modules-load=dwc2,g_ether, and an SSH enable file. USB gadget networking gives the Pi an Ethernet connection over its data port.
I set the account, hostname, and WiFi while imaging the card, then copy the matching boot files. That gives me a way into the machine before the tiny screen works. Any example SSH command also needs the username created during imaging, not whatever username happened to be fashionable when the guide was written.
USB power alone isn't enough. Use the Pi's data port and a cable that carries data. With headless access working first, I can still inspect the system when the display driver or button setup needs another pass.
Making the LCD show the desktop
The Waveshare 1.3-inch LCD HAT uses SPI. The build uses fbcp-ili9341 with the Waveshare ST7789 configuration to mirror the main framebuffer onto that screen.
I enable SPI, check the user's SPI and GPIO access, then build and test the driver. The original setup starts the binary through /etc/rc.local. Running it as a service would work too, but that's a change from the original files.
The panel works well for checking the desktop and handling small tasks. It doesn't make ordinary desktop apps comfortable at handheld resolution. Software is still annoyingly literal about available pixels.
Buttons and battery power
The joystick and buttons use the input script from the LCD HAT guide. It maps the controls to mouse movement and clicks, which is enough to get around without carrying a separate mouse.
The Waveshare UPS HAT provides portable power. Its monitoring example reads the INA219 over I2C, so I can check voltage and current separately from the display. I bring that up after the Pi and screen are stable.
The Zero 2 W has 512 MB of RAM, so the guide increases swap to help with packages and compilation. It makes a constrained build less frustrating. It doesn't magically turn storage into fast memory.
Build it one layer at a time
I'd still follow the same order: image the card, set up SSH, update the system, bring up SPI and the LCD, add input, then test power monitoring. A blank display and a network problem are both irritating. They're much easier to fix separately.
Once that's working, an enclosure or a different input script is a reasonable next step. The project stays close to standard Linux tools, so there's plenty of room to adapt it without replacing the whole setup.
The useful references are the project guide, LCD HAT documentation, and UPS HAT documentation. Pocket Pi is Apache-2.0, so you can use and adapt the files under that license.