openstm32hw README

The aim is to provide Open Source hardware designs for STM32.

This repository grew from a discussion thread on LeafLabs Maple forum:
http://forums.leaflabs.com/topic.php?id=1303

It was initially triggered by ala42 who had released a first cut at libmaple for STM32F4:
http://forums.leaflabs.com/topic.php?id=1268&page=2#post-7828

and siy's hardware design:
http://forums.leaflabs.com/topic.php?id=1303&page=2&replies=46#post-7882


Subdirs:

	MM4 - Leaf Labs Maple Mini clone for 64 pin F1/L1/F4 processors
		in 0.8" width and 2 layers.

	Mini64 - STM32 development board for OpenSTM32
		 Features:
		 - Small (52x38.4mm) breadboard compatible design.
		 - Support for STM32F103/F2xx/F4xx in 64-pin packages.
		 - Uses Eagle 5.1

	Mini48 - Reworked version of Maple Mini suitable for DIY PCB production
		and on-board RTC crystal. Uses Eagle 5.1

	Mini48U - Ultimate version of Mini48. Still suitable for DIY PCB production
		but smaller parts (0402) and optimized layout allowed make it in the
		format of original Maple Mini with 0.6" pin header rows pitch.
		Uses Eagle 5.1

	Mini48SE - This version is very similar to Maple Mini, but it does not 
		preserve its pinout. It also heavily utilizes second side to 
		achieve maximal possible density. As a consequence this version 
		is probably smallest STM32F103Cxx board - it has 0.5" pitch 
		and size is only 50.5x15mm. At the same time board uses no 
		extremely small components - all resistors and capacitors 
		are 0603 (one even 0805), LED - 1206, LDO - 1117.
		Uses Eagle 6.3.0
		The design is tested.

	Mini64SE - Different approach to boards based on MCU in LQFP64 package. 
		It has DIP48 format with 0.8" pitch. The design follows same 
		approach as Mini48SE and utilizes both sides. Separate 
		versions of design for F1 and F2/F4 series are provided. 
		Version for F2/F4 uses different ESD protection and lacks 
		external disconnect cirquitry. These changes are necessary 
		to enable F2/F4 chips work properly in all supported USB modes
		(Device/OTG) and with different powering (self powering and 
		bus powering).
		Uses Eagle 6.3.0 
		Design for F1 is tested, design for F4 still is not yet tested.

	Orone-mini - series of boards intended to be more easily 'DIY-able'
		than LeafLabs Maple-mini, and incorporate several improvements.
		The first boards, Orone-mini-S8x have pins 0.2" wider 
		than Maple-mini. They are otherwise software and pin-compatible 
		with Maple-mini (exception is 'av+' which is intended to 
		improve the power supply capability). 
                Not yet tested.

	PiXe-2: 'Stamp' format, 64pin STM32F103 MCU. Eagle 5.1
                Features: 
		- Dual-in-line 0.1" grid
		- 0805 or larger parts -> easier assembly
		- Internal Maple pins available & re-configurable
		- modest 10mil track/space rules DIY-able