The home-grown prototyping shield PCB for my Arduino Mega microcontroller is on the way, but we've run into a slight problem with regard to the price of the screw terminal blocks.
In a recent blog, I discussed the creation of a rather cunning prototyping board -- a dual-board combo, actually -- that is being designed by my chum Duane Benson for use with my Arduino Mega (see Creating a Bodacious Bensonfruit Arduino Mega Proto Screwshield PCB). I'm happy to report that this is well on the way; the design data was handed over to the board shop more than a week ago, and the first-pass versions should be back any day now.
Bensonfruit Arduino Mega prototyping screwshield.
for a larger version.)
As I described in my previous blog on this topic, there are several cunning aspects to our prototyping board. One of the things I personally like the most is that we are planning on using 0.1" pitch screw block connectors around the periphery of the boards.
10-way 0.1" pitch screw-block connector.
This will make it really easy to attach and detach external stuff like the switches and the motorized potentiometers and analog meters I'm using in my Pedagogical and Phantasmagorical Inamorata Prognostication Engine project.
There is one small fly in the soup, however. It turns out that these connectors can be rather expensive. Looking on the Digi-Key Website, for example, we find that a 10-position block (part number A98074-ND) costs $4.27, a 9-position block (part number 277-1280-ND) costs a whopping $6.04, and an 8-position block (part number A98338-ND) costs $5.29. Why should 8-way and 9-way blocks cost more than their 10-way cousins? Just another one of life's little mysteries, I suppose.
The thing is that our board combo requires 1x10-way, 4x9-way, and 5x8-way blocks -- all of which comes to a whopping $56.54. Now, our prototyping boards will still be really useful, even without the screw-block terminals, but they will be an order of magnitude more useful with the screw-block terminals. So, do you have any suggestions on where we might obtain these little scamps at a price that doesn’t make my lower lip quiver and my eyes water?