In my last post I introduced you to shopping safely and cheaply on eBay (which basically meant reading everything carefully and working smart with their search engine). Now with that groundwork over, here’s how to buy the tools and parts you need to work with electronics (and Arduinos) on eBay, including my own experience on what works and what doesn’t.
By the way, the list I’m working off of is taken from an excellent reference on building with microcontrollers, “Physical Computing”, by O’Sullivan and Igoe. While I’m still reading my way through it, it’s been a great introduction to using devices that let the microcontroller ‘sense’ the world. And although the book was written just before the Arduino became popular (and so the examples use other devices), the information adapts well to the Arduino, plus it’s a great introduction to electronics.
That said, here’s what I’ve found with eBay and parts, starting with tools:
Soldering Iron. I’ve used a cheap Radio Shack model for years, but have since switched over to a eBay version I found that I like a lot. Around $10, it’s an with a dial on the side. But if you plan to get into it in a big way, are considered quite good online; however a simple ‘pencil’ style iron will get you started. By the way, if you order one, order a with sponge at the same time; leaving your iron resting on anything else will soon give you (or your desk) a nasty burn.
Wire stripper or cutters. If you’re careful, a knife against the wire will do the job of removing insulation. But if not, there’s two kinds of wires stripper/cutters I’ve bought and used successfully – manual strippers (where you match the wire to the proper hole and pull) and automatic strippers (where you just insert and strip – quite cool, and easy to use). You can get on eBay via this link.
Multimeter. I’ve already blogged about buying a good multimeter (and which I’m quite happy with). However, if you don’t need all the bells and whistles, or are on a budget, you can get a super-cheap one that works fine for under $5 – just search on the models. Of course, don’t say I didn’t warn you when you want to upgrade to more features…
By the way, if you’re reading the shopping list that’s in “Physical Computing”, you’ll notice I left a lot of tools out, specifically a vise/third hand jig, glue gun, solder, needle-nose pliers, screwdrivers, and a toolbox. In my experience, you’ll find all these very cheap locally, cheaper than on eBay. For example, if you live near a Princess Auto (which Victoria BC has recently been blessed with), keep an eye on sales for many of these tools, as well as Canadian Tire. Recently, I picked up a metal vise for just over $8, and a hands-free jig for $2.50, both on sale at Princess. They are also fantastic for power tools, for example if you want to buy a hand drill, or a Dremel-style small drill for circuit board work.
That’s some of the tools for starting in electronics – now how about parts?
Miscellaneous components. Resistors, capacitors, diodes, transistors, and so on. For components like this, there’s two ways to stock up: Buy individual packets of items (like 2.2k resistors, 22k resistors, etc.) or look for a group of components. For that, just add the word ‘lot’ to your search on eBay, like resistor lot/capacitor lot/diode lot/transistor lot (or use for all four together!) If you’re going the individual route, two companies I’m happy with are are and – even when I search for the lowest prices on parts, it seems 9 times out of 10 I end up placing an order with one of these two. Speedy, professional, and I haven’t had a problem yet. Start small, and once you’re happy, make regular orders to build up your stock.
Power supply. The Arduino plug is a female 2.1mm plug with center positive, so you want a power supply to fit that (as explained on their site). The modular ones (nicknamed “wall warts”) are handy for powering your Arduino when it’s not plugged in to the computer, but more importantly, for powering all the devices you’ve connected to it. For example, I have a for my motors. You need a beefy power supply for motors, and 2 amps means the motors have enough to run on (and gives me one less thing to wonder about when things don’t work!) 5v is what the Arduino uses, but the designers recommend 9v or 12v for external power, depending on what you’re doing with it.
Power connectors. Like my using Molex connectors for my stepper motors, a good connector can make it a lot easier to plug and unplug. I recommend checking eBay for “” – while not always needed, if you use an Arduino motor shield (which can use a separate power supply), your life will a lot simpler if you use a connector to bring the power in (I take two wires from the connector to the screw terminals of the board).
Headers. These little parts are the connectors found on the Arduino – male and female, and they make it convenient to plug in things. I recommend buying a selection of both , as well as the cables that fit in them (called ). Using these wires, you can breadboard from the Arduino to test out devices. One warning: While the headers may not be necessary right away, you’ll end up using lots and lots of jumper wires right off – so consider ordering a couple packs ASAP (and maybe one pack of the for times the gender of the header pins is reversed).
Shrink wrap tubing. I’ve found it a handy thing to buy on eBay, and quite cheap. Get a 2mm-3mm thickness of , and any color you want. You can usually get 3 feet or so for around a dollar. I just use a cheap cigarette lighter to heat the wrap and shrink it, and the result looks better to me than electrical tape – but of course, you may prefer the latter.
Breadboard. You plug a wire in, and connect it to the Arduino. These things are great for hooking up circuits. And while I’m not a fan of the cheap ones I’ve bought on eBay, you may find a better selection. If you do search online, I recommend you look for the quality , and get ones in shrink wrap, with terminals and a back plane – not only do they look better, but they are likely to be more professionally made. And while a bit more than the cheaper ones, they are still less expensive than most anything you’ll buy locally.
USB stuff. The Arduino has a port called an A socket, identical to most printers. To avoid plugging and unplugging, I’ve bought many a . I leave them plugged into the microcontroller, since a $1 cable’s wear and tear suits me better than an Arduino’s connector breaking! As well, I’d recommend a , so your computer’s USB is somewhat separated electrically from the Arduino “just in case” – get one with its own power supply, and you might even be able to run a few devices without using a wall wart.
Miscellaneous. It seems every tutorial I read ends up requiring something I’ll buy on eBay. – if you order in advance and buy extra, you’ll start amassing a small pile of stuff, which means your next project may have the parts all ready to go!
That covers just some of the tools and parts you’ll need – but there’s more. Turn in shortly for the third (and final) part, where I discuss the best Arduino deals on eBay!