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The TK31 at an angle: a black board with a wide gold border, a black eight-legged memory chip near the top, two small capacitors under it, a white memory-chip icon with MEMORY, two small resistors at the lower right, lonely binary up the left edge, and a right-angle four-pin header.
VR

View it in VR

This board opens in a VR headset: life-size, or big enough to stand beside, with every pin and every part named where it sits. Open this address in the browser on a headset such as Apple Vision Pro or Meta Quest.

learn.lonelybinary.com/vr/tk31
You have this

EEPROM Memory

An AT24C128 I2C EEPROM on a TinkerBlock board: 16,384 bytes that keep their values with the power off, at address 0x50. VCC goes to your board's logic supply because the pull-ups end at VCC, each write takes up to 5 ms, a write wraps inside its 64-byte page, and each byte takes about a million writes.

Stores
16,384bytes, kept with the power off
I2C address
0x50fixed: one TK31 per bus
VCC
3V3 or 5Vyour board's logic supply
Each write
5ms max, then read it back
Start here · 01 The four pinsOpen the board in 3D

Turn it over and find the I2C PULL-UP jumper. All four holes are wired: VCC goes to your board's logic supply, because the pull-ups on SDA and SCL end at VCC.

Product questions & answers ↓

The whole handbook10 articles · 45 minQuick referencePDF · 455 KBEEPROM Memory model (GLB)GLB · 878 KBEEPROM Memory CAD (STEP)ZIP · 928 KBEEPROM Memory drawing (PDF)PDF · 2.2 MBEEPROM Memory drawing (DXF)ZIP · 32 KBAT24C128 datasheetPDF · datasheet.lcsc.comPinout and specsThe pin table, and the questions people ask first
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EEPROM Memory

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Need another

Not on general sale yet. Reply to your order and we will sort out a spare — quote tk31.

Order or missing parts?

Email us or reply to your order, and quote tk31 — that identifies the product. If something is missing from the bag, your order is the record of what shipped.

Take it with you

Point a phone camera at the code and this page opens there. It is the same address as the one printed on your box, so it is also what to show someone you are passing the board to.