Allied Component Works open hardware largely adopts the Digilent, Inc. PMOD form factor to provide direct and low cost solutions for evaluation of semiconductor component products.  A number of semiconductor manufacturers have also adopted PMOD for development boards of their own, making it a fairly widely recognized approach.  The hardware and software items discussed in this thread are all open source and low complexity by design, closely following the documentation and intent of the original component manufacturers.

Allied Component Works open hardware is also available on Tindie!

$18.00 Each In Low Qty	PMOD Adapter For Raspberry Pi
	This adapter is a fully passive Raspberry Pi "HAT" board that routes power and signals from the native 40-pin GPIO connector to a Digilent PMOD compatible host socket connector. Simple jumper se...

$18.00 Each In Low Qty	PMOD Real Time Clock
	This Digilent PMOD compatible peripheral module provides an integrated real time clock (RTC) chip with crystal in a popular form factor available from Micro Crystal and Abracon. This PMOD is typ...