Breakout based on the Quick2wire size, connection format, and concepts. Piggyback a Pi Zero on top of or below the input header as you please, with holes for standoffs. One I2C (6 pin), 1 SPI (8 pin) and a serial connector all using Q2W pinouts, compatible with their other boards found online and my others here. PWM1&2 (or GPIO12/13 - unprotected) on a 2 pin header, plus triple 5,3.3 and 0v headers, as well as 16 GPIO pins in 2 banks of 8 with 0v and 3.3V at either end. Resistors 6 * 10K, and two 330R 8 way networks RN1,2 (or use 16 singles). C1 10uF tantalum. IC1 LD117A33 (voltage regulator). Q1-2 (FET) VN10LP. The D10-5A signal diode array on the original Q2W board is impossible to get (or very expensive!), so the board uses 32 cheap 1N4148 diodes that do the "incorrect connection protection" job perfectly. Everything clearly labelled for easy assembly and use with wiringPI/Q2W and GPIO designations. Solder up as many of the connectors as you want!