Design Rock-Solid I2C Buses
from Pull-ups to Multi-Master Arbitration
A practical hardware-design course on the I2C interface: how the bus works, how to calculate pull-up resistors with confidence, how to hang many devices off one controller (and many controllers on one bus), and how to lay out, protect, and debug the result — with animated waveforms, interactive Plotly charts, and a design calculator.
Course Modules
Work through in order, or jump straight to the topic you need today.
What is I2C
Two wires, one protocol: open-drain drivers, wired-AND, speed classes, and when to pick I2C over SPI or UART.
Protocol Essentials
START/STOP, 7-bit & 10-bit addressing, ACK/NACK, clock stretching and the three transactions every design uses.
Pull-up Resistor Design
Rmin/Rmax with worked examples, interactive rise-time charts, and a calculator that gives you the E24 value.
One Master, Many Slaves
Multi-drop topology, address planning and conflicts, multiplexers, bus buffers, and mixed-voltage level shifting.
Multi-Master Buses
Clock synchronization and lossless arbitration explained with an animated waveform — plus when to avoid multi-master entirely.
PCB Layout & Signal Integrity
Routing rules, series damping, crosstalk, return paths, and running I2C over cables with bus extenders.
Robustness & Debug
ESD/TVS protection, the 9-clock bus-unlock sequence, hot-plug, and reading failure signatures on a scope.
Standards, Variants & Checklist
SMBus/PMBus differences, an I3C teaser, a printable 15-point design checklist, and FAQ.