Old smartphones vs. Raspberry Pi: a cost breakdown
Original: Why get an expensive Pi when I have an old phone?
Why This Matters
Repurposed consumer hardware could undercut embedded compute costs significantly at scale.
A maker compared used Android phones (¥300–500) against a fully equipped Raspberry Pi 4 setup (~¥2,317) for a camera/GPS/lighting project, finding rooted handsets already pack most required hardware.
Builder and digital artist behind so.long.thanks.fish was designing a PCB-based system needing a high-res camera, GPS, storage, and light control — and watched the Raspberry Pi 4 bill climb past ¥2,317 (~$347) once cellular, RTC, UPS, and display HATs were added. A used Redmi 13C 5G or Huawei Mate 30 5G sourced from Taobao for ¥300–500 (~$45–75) already includes all of that in one unit: 40–50MP cameras, GPS, 64GB storage, a battery, touchscreen, 5G modem, and a USB-C port for connecting a custom light-controller PCB. The author has rooted the Redmi, tested scheduled sleep/wake cycles, and used Codex to configure components over USB. The Huawei, harder to root, is being used in kiosk mode instead. A parallel camera comparison between the Redmi's 50MP JPEG output and an Arducam 64MP module is underway — raw megapixel count alone doesn't settle image quality. The main unsolved problem is scale: sourcing two matching phones is straightforward; sourcing hundreds with consistent battery health and camera behavior is a different challenge. Beyond this project, the author floats a compelling application for digital art installations — shipping clients a pre-configured phone that just plugs into a display, with remote access over mobile data, no gallery Wi-Fi required.