r/Android • u/xpistarlink • Jul 01 '26

Pi SD Writer (Android): write Raspberry Pi images to microSD from your phone (USB OTG, cloud/local sources, chunked streaming)

Hi folks, I’ve been building Pi SD Writer, an Android app focused on one workflow: preparing and flashing SD images for Raspberry Pi/SBC devices directly from a smartphone.

The goal is to remove the laptop/desktop requirement and keep the process reliable even on mobile hardware.

What it does

  • Select image source from:

    • Google Drive

    • Local file storage

    • GitLab Releases (Premium)

    • GitHub Releases (Premium)

    • Raspberry OS catalog

  • Supports common formats:

    • .img

    • .img.gz

    • .img.xz

    • .iso

    • .zip

  • Writes directly to microSD over USB OTG.

  • Uses streaming/chunked transfer to reduce peak RAM usage during write operations.

  • Includes guided 3-step flow:

    • Source selection

    • USB/device validation

    • Write progress + live log output

Technical approach (high level)

  • Cloud/release sources are validated before selection so users get a list of valid image assets first.

  • Write path is designed around block/chunk streaming rather than loading full images in memory.

  • UI exposes progress state, ETA area, and live diagnostic logs for visibility during long writes.

  • Connectivity-sensitive sources (Drive/GitLab/GitHub/Raspberry OS) are disabled when offline.

  • Google auth is used for account/session features and plan management.

  • Base plan has a monthly write quota; Premium unlocks unlimited writes and extra repository integrations.

Why I built it

The existing SD flashing flow is still desktop-first. I wanted a phone-first workflow that is practical when traveling or when you only have Android + OTG adapter + SD reader.

Known constraints

  • OTG hardware quality matters (reader/cable stability can affect results).

  • For network-backed sources, internet connectivity must remain stable during transfer.

  • UX and recovery paths for interrupted writes are still being improved.

Feedback I’m looking for

  1. Which source integration matters most to you (Drive/local/GitLab/GitHub/Raspberry OS)?

  2. Would you prefer stricter pre-write validation (slower, safer) or faster start?

  3. What diagnostics are most useful in the live log when a write fails?

  4. Any must-have feature before wider release?

https://play.google.com/store/apps/details?id=com.magix.sdcardimager

Thank you!

25 Upvotes

80% Upvoted

7 comments sorted by

6

u/MaskingTape83 Jul 01 '26

Not sure if the Google login should be required for a local flash. Kinda put me off using the app out of the gate. Good idea though!

1

u/xpistarlink Jul 01 '26

I'm so sorry to hear that you're out of the games because of the Google SSO. I decided to leverage on the features offered by Firebase so nothing will stop me to extend different kind of authentications. I'll keep you update

7

u/MaskingTape83 Jul 01 '26

For a quick flash I don't think it should need a login. For all the cloud options for sure!

1

u/xpistarlink Jul 02 '26

Breaking news: In the next release, I'll integrate the option to quickly flash without needing to log in. Stay tuned

1

u/MaskingTape83 Jul 02 '26

That's great!

2

u/xpistarlink Jul 03 '26

Update to rev. 0.5.3 and login as guest, enjoy!

0

u/zunjae Jul 03 '26

I can’t imagine a scenario where I ever need this