Back in the old days of 2014 when Radio Shack still existed, you could drive up to any strip mall in America and buy D-sub connectors that were made all the way back in 1972. Yes, connectors for all those SCSI, serial, parallel, and other weird ports you’d find on old computers could be bought for less than five dollars. For some reason or another, [yesnoio] has a ton of these connectors. Not just the connectors, but also those little plastic shells that clip onto the connectors. What to do with them? Retro Modules! It’s basically littleBits if littleBits were invented in 1987.
The goal of Retro Modules is to be able to put prototypes into your backpack without tearing a wire or two out of a breadboard. The basic foundation is to have a specification that outlines the pinout of DB-25 and DE-9 connectors, using these signals for power, an I²C bus,. analog lines, and SPI lines. Put a microcontroller in one of these plastic shells, a sensor in another, and a display in a third; you have an electronics prototyping platform that was designed in the backroom of a Radio Shack.
[yesnoio] has a Getting Started guide that takes you through the creation of the first three Retro Modules. The first is an Arduino nano or micro stuffed into a plastic shell with one female DA-15 connector. The second module is just a LED and resistor, and the third is just a servo. These can be connected together, and controlled because of the specification lined out. It’s brilliant, a little bit crazy, and something that has the potential to be much, much cooler than any electronics prototyping platform you’ll find at Maker Faire.
I was just going to say, sit on them! As electronics become smaller and smaller these will become useful again (at least as a shell). I bought a nes case for cheap a few years ago to build my computer illiterate parents a cheap microatx pvr and now I have a rasp pi that is multitudes too small for such a large case. (also http://www.thingiverse.com/thing:307832 ).
Removing I/O pins from availability but still requiring one IN and one OUT port doesn’t make much sense. Eg if module A consumes I/O 1 and you want to attach more than one module A which also uses I/O 1. You can’t without additional circuitry or glue logic to accomodate. What about capacitance or signal delays due the amount of copper between modules?
Oh well good luck…..
You implement a set of dip switches on the module to reconfigure it if you’re not going to use a bus protocol.
Yeah’ I thought of that too. But the article does say that the 15 pin is intended for “beginners”. DIP switches would allow any position in the chain but it would be error prone as the beginner forgets to make adjustments between changes.
If I was tasked with this design and hobbled by the constraints of using only D -Sub connectors, I would spec either no daisy chaining or automatically shift the data lines and pull the (now higher) lines low if the device “takes” data lines. Then assign a number to the data line devices. 0 for none 8 for all. As long as the sum is at or less than 8 you should be fine. Programs will have to be modified to accomodate changes in chain position. But that would be done anyways since it’s likely changing the chain is a result of the hardware changing.
One solution places the burden on hardware the other on software. Pick your poison.
And I just read his project page, where he suggests using removable-pin D plugs, so you can reconfigure the interface as needed…
Seeing as I have a bunch of old computers, Amiga, Commodore, Atari, Apple I find that my box full of these various adapters are very useful. Sometimes just to take apart to make sure it’s perfect for what I’m doing. I about a year ago picked up a box of 9 pin serial cables because they are great when you need to make special cables for whatever.
I did this 13 years ago when building my first ever avr programmer. Used a nice little parallel port gender bender, ripped the guts and one of the sockets out, put my 74ls244 inside and voila, parallel port stk200 clone avr programmer in a nifty little pluggy thing.
When the Radio Shack still existed? My not so large and definitely not so maker shopping friendly city still has a Rat Shack. Sure, it’s owned by Sprint but it still has what components, books, kits and tools that it carried a year ago. My understanding is that Radio Shack corporate still exists and still plans to be selling this stuff through the Sprint owned stores.
So we are down from about 5 or so locations to 1. How many places did we need to buy the same stuff anyway? I have long thought that they should have thinned out their stores to reduce overhead although the one that stayed open is NOT the one I would have picked.
Now if they would just lower their prices on components to something reasonable maybe people would buy more and just maybe they would see the need to carry more variety. I’m rather doubtful that you bought those DSubs for less than $5 at a Radio Shack, at least not in the last couple decades. Unless.. maybe if it was a closing clearance sale.
Microcenter has what you need.
Well.. first off Microcenter is nowhere near as ubiquitous as the Rat Shack even after bankruptcy. I have to drive 75 miles to get to one and it’s in an area of congested traffic where everyone drives like angry children.
It’s been quite a while since I’ve been there. The last I knew they only sold plug together stuff like Arduinos and shields. That stuff is convenient I guess but not really worth it when you consider how easy it is to just plug chips into a breadboard and how much cheaper the chips are that way. Besides, I am interested in analog and RF projects too. Do they carry discrete components and ICs now?
Hmm.. decided to check their website. Apparently they do stock discrete components now. They still don’t have the selection of transistors or ICs that RadioShack has though. (Not that I am implying the Rat Shack’s variety is sufficient either)
I have a cabinet of older connectors, plugs, cables and converters, all brand new in sealed packaging :/ I bought out whole stock from closing computer store ~2000 and used to sell them at computer market in Poland (open sky market like Hamvention, but every weekend all year round). Sold most of it, but still have about 3 CRT boxes of stuff. db9, db25, VGA, 13W3, Krone, SCSI, Ps2, Din!, proprietary Cisco, all the “good” stuff (read useless 0 value) :/
Project sounds interesting, but I think nowadays those types of connectors are too bulky, people expect lean microUSB on products, or ordinary pin strips on dev stuff.