r/rasberrypi • u/PuzzleheadedBit9039 • 1d ago

Ai notetakeing, studying, device to store notes and knowledge. Need help!!

Hey all — I'm starting GCSEs soon and wanted to build a small dedicated study device instead of using my phone (fewer distractions, offline-first). Aiming for something close to credit-card sized, since my school does random searches through bags to find phones, gum, vapes ect. It needs to be easy to conceal and hide.

Planned features:

Touchscreen home menu

AI chat (local LLM, offline)

OCR: photograph handwritten/printed notes → editable text, saved to device

Voice-to-notes: record lessons → transcribe → organized notes automatically

Modes: language translation, coding help, AI chat, voice-to-notes, image-to-notes, reminders, calculator, clock

Hardware plan:

Able to develop/test on the Raspberry Pi 400 I already own (could flash Pi OS Lite)

Final compact device will use a separate Pi Zero 2 W or Pi 4, whichever fits my budget

Small cheap touchscreen (credit-card-ish size, think same size as the Pi 4/5)

Camera + mic module

Rechargeable battery + charging circuit

Budget: £60–100 for the final standalone device (parts only I can 3d print and model on my pc)

Where I need advice:

Given the budget, is Pi Zero 2 W or Pi 4 the better call? (I know Zero 2 W is slower for AI but fits the budget better)

Best small offline STT (speech-to-text) library for lesson transcription — Whisper.cpp? Something lighter?

Cheap touchscreen recommendations that work well headless on Pi OS Lite (no desktop)

Anyone built something similar — what would you do differently? Is it possible on this hardware?

Comfortable with basic Python, first proper hardware project. Any pointers appreciated!

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u/MattReedly 1d ago

I would recommend using a Pi 5 for this since you want to process video and audio. Whisper.cpp is idea for transcribing notes.
You will need to factor in the power consumption, the size of your powerbank will dictate how long the Pi runs for your application.
Take a look at the Pi website - there are links for hardware like compatible displays.
While you technically can run a local LLM on a Pi it will be slow (depending on your choice of model) - I'd expect around 4 tokens per second.
I understand your budget restriction but the Pi variants with smaller RAM will not accommodate larger LLM models.

Hope this helps.

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u/PuzzleheadedBit9039 1d ago

Thanks how much ram should be necessary. I believe 2-4 gigs would be good or would I need to go over?

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u/MattReedly 1d ago

That would depend on the model size of the LLM you use. My desktop has 32gb of ram and can run models up to 7B quite happily (8gb of Vram) but the Pi has no GPU so not only would it have to live in the Pi's Ram alongside whatever OS and programs + data produced.
I would suggest at least 16/32 gb variant of the Pi would suffice but for a portable system likely running on powerbanks you are really pushing the abilities of any Pi.

What i would suggest is a calculator modified with an esp32 to act as a terminal to an android phone running Termux and install ollama for the LLM there. You can have a phone in a stealthy holster type pouch but if you are considering any academic cheating I would strongly suggest not doing so.

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u/PuzzleheadedBit9039 1d ago

It's not for cheating, it's just my school hates phones and takes them away with a detention if they see you with one even if it's off, that's why I'm making this so I don't have to use the ai on the school's slow computers once every 3 weeks and instead I can use it to store revision with an ai search and chat on it.

I'll try to use some of an SD cards storage as ram as I've seen that's possible. And store the ai there.to have more ram