[Windell] over at Evil Mad Scientist Laboratories has reached out in order to help them identify a mystery piece of electronics equipment they came across a few years ago. Discovered at an electronics surplus store, the mystery component looks like a cross between an over-sized chess board and a breadboard. Failing to identify it they eventually disposed of the board, snapping a couple of pictures for good measure before it was gone for good.

Recently while visiting a local electronics flea market, they came across what looked to be a similar, though much smaller board. This piqued their curiosity and compelled them to dig out the pictures of the mystery board in hopes of finally discovering what it was. Using markings on the new board they found, the team at EMSL located some images of a patchboard cartridge that looked quite similar to their mystery object. Upon closer inspection however, they think that the two pieces might be related, but are not quite the same item.

Swing by their site and chime in if you happen to have any good leads – we’re sure they will appreciate it.

We asked for responses to our last Development Board post, and you all followed through. We got comments, forum posts, and emails filled with your opinions. Like last time, there is no way we could cover every board, so here are a few more that seemed to be popular crowd choices. Feel free to keep sending us your favorite boards, we may end up featuring them at a later date!

The Popular:

Parallax Propeller: We heard the loudest cries from the Parallax fans out there. The Propeller is a unique chip, in that it contains 8 cores called cogs which each take turns executing separate code. This design allows for disregarding of interrupt style programming in favor of assigning each core a specific task. There are a number of boards available, including Gadget Gangster’s platform as well as boards from Parallax. Thinking in terms of 8 cores rather than one may present a learning curve to some embedded programmers, though there are a number of code examples to pull from online to get beginners on their feet.

Atmel’s AT90USB and AT32U4 based boards: Atmel’s AT90USB and ATmega32U4 chips are common on low part count boards like the Teensy/Teensy++ because of their built-in hardware USB support, which means no FTDI or equivalent chip required. These development boards tend to be low-cost, easy to implement on a breadboard, and in cases such as the Teensy, are Arduino IDE compatible. The chips these boards are based on are also an excellent place for those trying their hand out at microcontroller circuit design for the first time because of their simplicity and low hardware requirements.

Microchip’s PIC line: Somehow, we managed to leave the entire Microchip crowd in the cold last time. A popular set of microcontrollers with a similar market segment to Atmel’s chips, these chips vary from the low-end and low-cost 8-bit series to the higher end 16 and 32-bit models. We received a good number of development board recommendations, all ranging in price, features, and ease of use. We’ll rely on comments and forum posts to help convince you what specific model to try.

[edit: Added the PicKit3 as per popular request]

The Powerful:

mbed: Possibly one of the most popular hobby development boards for ARM’s Cortex-M3 chip, the mbed features a similar footprint to the Teensy, but with a huge jump forward in power. The mbed includes hardware for a number of peripherals, including support for ethernet with the addition of an RJ-45 port. The major difference between the mbed and other similar boards is the entirely web-based IDE. We have previously reviewed the mbed, so for more details be sure to check it out.

Renesas’ RX62N RDK: Whenever a company gives away development boards for free, the community often jumps on the offer. Rather than the normal free barebones boards though, the RDK has a good number of on board peripherals, including an Ethernet port as well as a 3 axis accelerometer. Unfortunately you can’t get one for free anymore (at least not this contest), but from all we have heard from our readers, it may be worth investing in anyway.

The Maple: The Maple from LeafLabs is an excellent example of the effect open hardware tools such as the Arduino have had on the hobbyist environment. Featuring an ARM Cortex-M3, the Maple has plenty of processing power and also can brag that it has the same header layout as the Arduino. This means that almost all commercially available Arduino shields will work on the Maple, a major selling point for anyone who has invested into a well stocked Arduino setup but needs an injection of performance.

Bonus Points:

OpenWRT based routers: Often, projects need to be networked either by wire or wirelessly to operate as desired. Rather than buying a high-end development board with ethernet or Wi-Fi built-in, many readers suggested buying (or salvaging) any one of a number of low-cost wireless routers, and installing a custom linux based firmware on them. These boards often tend to have UARTs or USB ports originally meant for debugging available for expansion with sensors or other low-end microcontrollers. A hack in the true sense of the word, we applaud this sort of creativity. Some popular firmwares to check out would include DD-WRT, OpenWRT, and the Tomato firmware. Be sure to make sure support exists for your device before you go buying anything though.

FPGA boards: When we set out to cover development boards, we had microcontrollers in mind. However when it comes to signal processing, custom high-speed logic, or flexibility, FPGAs are an excellent choice. The two major players for hobbyists these days are Xilinx with their Spartan line, and Altera with their Cyclone line. Both companies offer their IDE for free, and it comes down to personal preference when choosing which way to go. Both companies also support SoC designs to implement virtual microcontrollers on the FPGA, which adds an additional layer of flexibility for any hobbyist or engineer. Chances are, most hobbyists will not need the performance of cutting edge FPGAs (or CPLDs), so keep an eye out for older development boards on sale, or development boards made by third parties.

Build your own: Although it may appear as a sort of “Get off my lawn” answer to our question, there is a lot to be said about building a development board from scratch. These days, many 8-bit or 32-bit microcontrollers require few if any external components to run in a basic mode, and can be combined with a JTAG or FTDI cable for programming and communication. There are countless tutorials on using perf-board or etching a board to make a custom circuit, and the experience is invaluable for breaking away from high cost development boards in simple projects.

Who would have thought that some corn starch could be made into toner transfer paper? We’re not sure of the advantages (perhaps its cheaper?), but if you have a lot of time or just love to get sticky [Matthew Sager] shows the proper method for making the paper, printing, and then etching a PCB.

If you’re just getting started making PCBs, we recommend you check out these DIY circuit etching videos to get a better grasp on the printing and etching steps.

An accurate drill press is an essential tool for making your own through-hole printed circuit boards at home. Reader [Josh Ashby] offers up a solid design using scrap bin materials.

A major issue with PCB drilling is that even the slightest horizontal play will snap the delicate carbide drill bit. Hobbyist-grade tools such as Dremel’s drill press attachment are usually too sloppy for this task, while a more precise instrument might set you back a couple hundred bucks.

[Josh’s] design uses a nylon “sled” moving vertically in an aluminum u-channel track. Most of these materials were salvaged or were acquired inexpensively from a local hardware store, and assembled in less than a day. Surprisingly, this low-tech approach has proven sufficiently smooth that he’s yet to break a bit while drilling. And the entire setup, including the knockoff Harbor Freight rotary tool, cost less than the wobbly name-brand accessory alone.

Circuit-bending blog GetLoFi has posted the best tutorial yet on home-made printed circuit boards using the toner transfer method.

We’ve covered homebrew PCB fabrication techniques about a billion times before. What sets this tutorial apart is that it collects many bits of knowledge otherwise scattered all about the web, and then depicts the entire process on video, from initial printing to cut PCB…because reading about it versus seeing it done are two different things entirely. They give a number of immensely useful tips throughout: choice of materials and where to get them, tools and techniques, and dispelling several myths about these methods (for example, they’re adamant about not using acetone to clean toner from the PCB). Well worth the 30 minutes to watch. If that’s too much and you’ve been stuck on just one part of the process, the tutorial is in three segments.

Trimming finished boards on a paper cutter? Who would’ve guessed?

[via Make]