Free resource
i2c cheat sheet
Everything you reach for mid-project on one page — connector pinouts, the common addresses, pull-up values, speed modes and the 7-bit/8-bit rule. Free to download, print, or share (CC-BY).
What's on it
Everything on the sheet, with the full reference
The cheat sheet is the quick version. Each part of it has a complete page behind it:
- Connector pinouts — Qwiic, STEMMA QT, Grove, STEMMA and Gravity pin order and voltage: the i2c connector standards, or check a specific pairing with the compatibility checker.
- Common i2c addresses — the full, searchable list of every part by 7-bit address is the i2c address list, with the conflict guide for when two share one.
- Speed modes — Standard through High-speed and why turning the clock up can make a bus less reliable: i2c speed modes.
- Pull-up resistors — the 4.7 kΩ default and when to go stronger: pull-up resistor values.
- 7-bit vs 8-bit — why a datasheet's 0xEC is your scanner's 0x76, explained on the address page.
- Scanning the bus — ready-to-paste scanner code for Arduino, the Pi and MicroPython: the i2c scanner guide.
Using it somewhere? The sheet is released under CC-BY 4.0 — free to embed, print for a class or workshop, or share, as long as you credit i2c.net. The address data behind it is also an open dataset on GitHub.