K3ng Keyer Schematic Repack |link|

Use the SDA (A4) and SCL (A5) pins. A 16x2 I2C LCD allows you to see your speed, memory contents, and settings without needing a computer.

Several projects tagged “K3NG” have repackaged the schematic into a polished, single-page SVG graphic, ideal for printing and framing above your workbench. k3ng keyer schematic repack