With the prices for FPGA (Field Programmable Gate Array) chips coming down all the time, FPGA development has become affordable for the electronics hobbyist. I was looking around at starter boards and saw several recommendations for the Digilent Spartan-3 Starter Board. At $99, it is one of the cheapest boards available, yet it has some pretty impressive features. Take a look at what you get for your $99:

• Xilinx Spartan-3 FPGA with twelve 18-bit multipliers, 216Kbits of block RAM, and up to 500MHz internal clock speeds
• On-board 2Mbit Platform Flash
• 8 slide switches
• 4 pushbuttons
• 9 LEDs
• 4-digit seven-segment display
• Serial port
• VGA port
• PS/2 mouse/keyboard port
• Three 40-pin expansion connectors
• Three high-current voltage regulators (3.3V, 2.5V, and 1.2V)
• 1Mbyte on-board 10ns SRAM (256Kb x 32)

It even comes with power supply and programming cable, neither of which is included with many boards. It is designed to work with Xilinx’s free WebPack, a good set of FPGA programming and simulation tools. You will need to learn VHDL or Verilog, but there are many good books and tutorials available. I would recommend Circuit Design with VHDL as a good choice for learning VHDL.

If you have any interest in experimenting with FPGAs, then this looks like a good board to investigate.

The principle behind this type of battery (or wet cell) is very simple: dissimilar metals placed in an appropriate solution will conduct electric current. But the specific materials used are what determines how well it works. To test materials, Hans Summers created batteries using lemons, lemon juice, bleach, salt, and vinegar. Best of all, he logged his results and provided a spreadsheet that you can download including all of his raw data. The article is quite interesting and well worth a look if you have every wondered how far homemade battery technology could be taken.

All Radio Shack stores used to have large electronic sections. They had drawers of LED’s, resistors, capacitors, diodes, connectors, and even some integrated circuits. The parts were overpriced compared to mail-order merchants, but the convenience of being able to walk out with just the part you needed was worth a lot.

But now the selection of electronic parts in a Radio Shack store varies greatly depending on the store. One store I like to visit still has a large electronic section. They even have some unusual items that you wouldn’t expect to see there, such as BASIC Stamp modules and starter kits. The manager is friendly and has an interest in electronics, probably explaining the large number of parts.

A more local Radio Shack is, I suspect, more typical. It is almost all cell phones and televisions, with only a small corner containing a few shopworn electronics parts. Who would want to buy PCB etchant in a box faded nearly to white, coated with a thick layer of dust?

I can understand why Radio Shack (or RadioShack as they are known now) wanted to move away from their electronic parts image. But it is still a shame that they have abandoned so much of what made their stores different.