Thursday, April 5, 2012

Green Boards

Big Brain Green Board - Made in Heaven!
Green Boards - Supplement to Cognition 1

 The Green Board is from HONDA and measures 7 x 10-inches and fits the CC Containment Cabinet drawer for the new stat super computing Big Brain. Each CC drawer is 21cm x 33cm or 8.3 x 13-inches.

Off-the-Shelf boards for Multiple Propeller Projects

Supplement to Cognition #1
News Caption: Breadboards or Greenboards

Green boards, Propellers & Sockets
Here's what Cognition has to say about Green Boards.
Breadboards or Greenboards a long debated issue, in the case of maximum over-clocking, are there limitations on what you can do with breadboards and higher clock frequencies? Take into consideration the wide band connecting conductive plate structure of the breadboards. Examine these differences and choose a suitable board. Green boards can have ideal configurations just waiting for component placement, and may not have challenges of breadboards with overclocking.

This is a more permanent printed circuit board that requires soldering to accept components and sockets and replaces solderless breadboards. Big Brain array solderless breadboards, while still functioning well in almost two years of use, may have some fatigue at a future time. Fatigue anticipated may originate from a relapsed spring constant, a corrosion or tarnish caused by incessant atmospheric pollution, or dust contaminants and blockage. 

Board Type
See the higher resolution photo - there's a big interest in these commercial green boards. These are pre-made pre-etched off-the-shelf ready to go printed circuit boards, sold at the parts store in China. They were personally hand picked from the lot for the Big Brain project. From what I can tell from the board, they are high quality, sold in China and manufactured for or by HONDA for one of their large projects, perhaps robot ASIMO or a pure prototyping project.

There's no set pricing in China, you just go to the parts skyscraper, find one of the 500 stores with the boards, and barter to get good pricing. One tip for the barter technique is to hide. Yes, hide. Have a local friend buy the boards for you. When the store clerks see a "foreigner" with white skin, the price immediately goes up by several factors.

Board Layout
The layout is perfect for Propeller chips, putting these close together for connection in as little as .75-inch apart (could do overclocking with the minimal prop to prop distances) and there's enough end space for EEPROMs, LEDs etc. Boards are about 7 x 10-inches. Spacing is standard for sockets and Propeller chips.

Board Utilization
I've experimented with several layouts and there's even some islands at the board side for special circuits like external oscillators, filters, speakers, TV, and supporting components. At least 12 props fit on one board. The photo shows the solder pad arrangements and connections. It sort of like a giant deluxe radio shack board from Heaven.

Mounting and Layout
The components are normally mounted on the back side but the sockets are shown on the front side to more readily show Propeller socket positioning. The board as power and ground bus bars and the four island groupings are especially useful. There's additional space for a Prop Plug connector, decoupling capacitors, eeproms, crystal, LEDs, video, mouse, keyboard connectors, and support circuits. I started out with 10 props to a board but the design is now it's up to 12. 

We now have around 35 to 40 of these boards for the big brain, enough to hold up to 480 DIP Propeller chips or 3,840 cogs or 480,000 EV processors.