The USC Andrew and Erna Viterbi School of Engineering USC Ming Hsieh Department of Electrical Engineering University of Southern California

EE 459Lx - Embedded System Design Laboratory

Recommended Tools

So you're taking EE459 and your parents ask "What would like for your birthday?" Since you're an engineer, and all engineers need tools and other equipment to work on projects, you decide it would be nice to have some of the tools that we use in the EE459 lab for your own, but what should you ask for? Below are some of the items we either use in the lab, or would probably buy to replace what we have now.

Soldering Iron

All electrical engineers need to own a soldering iron. And you don't want one of those cheap ones they sell at your local electronics store, you deserve a professional one. All the benches in the EE459 lab are outfitted with a Weller WTCPT soldering station, and this is our recommended soldering iron if you want one for personal use.

Warning: they aren't cheap. Prices are usually about $150 to $200, which makes people wonder why they shouldn't just buy the $15 one at Fry's. Hard to justify it in print, but after using these and their predecessors for 40+ years, I've come to appreciate their quality. They are thermostatically controlled which means they come up to the right temperature very quickly, maybe a minute or two, and then they stay at that temperature. If you accidently leave one on over a weekend, which our students do, they won't melt and burn things up. It will just be sitting there Monday morning ready to go at the same temperature as it was Friday afternoon.

All the parts on it are individually replaceable. If the iron (the thing on end of the cable that heats up) breaks, disconnect it from the base unit and replace it. The soldering tips are also individually replaceable, so when the tip gets all black and crusty, just toss it and put in a new one.

You might be able to find an older model at an electronics swap meet and pick it up for a lot less. Earlier models looked a bit different and had model names like "WTCP" or "WTCPL" but are basically the same.

These are available from Amazon and other online sources. Shop around for a good price and then buy it. If you take care of it, it will probably last for the rest of your engineering career.

Update: 6/19 - It appears that Weller has discontinued the WTCPT model although they are still available online from many places. What a shame. As far as I can tell the closest thing they now make as a replacement is the WT1012N soldering station. It's probably a better product, but at nearly $400 it better be.

Desoldering Tool

If you're going solder eventually you will need to desolder something. The cheap, and sometimes surprisingly effective solution, is the copper braid solder wick from companies like Chem-Wik. Use the soldering iron tip to press the braid down over the solder to be removed. Once the solder melts it gets absorbed, to varying degrees, into the braid. However we also suggest that you have a desoldering pump tool handy. A good one is the Edsyn DS017 Soldapullt.

It's reasonably durable, the tip is replaceable, and it's easy to take apart to clean out the solder gunk that collects inside. There are a bunch of copy-cat models from you-know-where that look just like it, but the Edsyn ones seem to last longer so that's the one we recommend. Cost is $25-$30 and can be found at Fry's or online.

There are also smaller ones from a bunch of companies that cost under $10 and sometimes work very well. They all look about like the one below and we have no idea how to pick one over another. Probably can't go too far wrong with any of them.

Wire Strippers

For stripping wire, we recommend the Ripley Miller Model 100 stripper. There are lots of other ones that look similar but these seem to work the best, at least for us.

They are available for $15-$20 from several vendors. Just make sure you are getting one from this manufacturer. There are many wire strippers on the market that look similar and cost less, and we use some of these in our classes, but if you are buying one for personal use get the real thing.

We do a lot of wiring with 30 gauge wire and wire wrapping tools. Getting the wire stripped properly goes a long way towards making a good wire wrap connection. You can buy a $50 stripper specially designed for 30 gauge (and only 30 gauge) wire, but we've found that these work about as well, are a lot more flexible and cost a lot less. The only drawback of these is that it's hard to get them adjusted to strip a certain gauge of wire. The screw in the handle is used to set how far the blades close down on the wire but getting it adjusted is a pain. However if you plan to use these for lots of stripping of one size of wire, like we do for 30 gauge, it's worth taking the time to precisely get it adjusted to strip the wire without nicking the wire and breaking it.

Screwdrivers

Everybody needs screwdrivers, and the Xcelite PS88 screwdriver set has been around for years and is still a favorite of many people. Maybe not as versatile as a collection of separate, full size screwdrivers, but for working on electronics projects these small ones are usually all you need. You get five flat-blade and three Phillips screwdrivers, plus a gizmo that can fit over the handles to give you a better grip and more turning power, and a nice box to keep it all together. You should be able to find it in the $30 to $40 price range.

At some point you're also going to want to have a set of nutdrivers. Try the Xcelite PS120 with ten different nutdrivers in the set. These go for around $45.

Metal Nibbling Tool

Lost of electronics projects eventually end up installed in some sort of box with the various displays and controls poking through the box surface. Getting all the openings made in a metal box can be a chore. Using a hand file will eventually get the job done but a metal nibbling tool is a much better way to make something like a rectangular hole for an LCD display. For this we recommend the "Adel Nibbling Tool". These can be found from various online vendors for something in the $25 to $50 range. I've had one for over forty years and still use it regularly, mostly with aluminum but it also cuts steel up to about 1/16" thick. You drill a hole about 3/8" in the material and then stick the cutting end of the tool (the thing at the lower right in the picture) through the hole. Start squeezing the handle and the cutter nibbles away the metal about 1/16" at a time leaving a cut about 1/4" wide. It can be slow, but when compared to other hand methods this comes out way ahead.

Test Jumpers

These little clip leads are extremely useful for making temporary connections between parts of a circuit. They are manufactured by E-Z-Hook and called XM Series Micro Hooks. When you press on the big end, a small hook extends out the skinny end and it's the right size for hooking onto the post of a wire wrap socket or other parts of the circuit.

They are not cheap. A set of ten of different colors (Part Num. 204XM-12-S) is around $50 and is available from Digikey. Jameco sells similar ones from other manufacturers for far less, and while these work we find that those fall apart on a regular basis, at least with students using them. The E-Z-Hook ones are much better made and if you are buying them for personal use, go for the quality.

Multimeter

A multimeter for measuring voltage, current, resistance, and other conditions is the one piece of test equipment that any EE should have in their toolbox. In the EE459 lab we use bench-type meters that sit on the bench and run off AC power. If you want one of those be prepared to pay $500 or more for a decent one. However you can usually get by with a battery powered handheld model that will do all the same things, and cost at lot less.

When shopping for a meter, make sure to get one that measures at least these parameters:

and if possible also does these:

Continuity is just a resistance measurement but it should sound a tone if the resistance is close to zero. Makes it easier to use for checking continuity in wires. The better meters will also say they do "True RMS" measurements of AC signals which gives a more accurate measurement of non-sinusoidal AC signals.

Meters that will do all or most of this are available from online sellers from about $20 on up. The ones at the lower prices will probably lack one or more of the features listed above, and their reliability may be suspect. However it may be a wise investment to get started cheaply and then plan to upgrade later.

At the upper end of the price range are meters like the Fluke 87-V ($400). Fluke has been a reliable brand for years so this would be a good choice if you are willing to spend that much. In the middle is the Fluke 115 ($160). The 115 is missing features like microAmp and milliAmp resolution on the current measurements but if you can live without that this is probably a good meter.

Oscilloscope

You can do a lot of electronics work without an oscilloscope, but having a decent scope can make the difference between getting a project to work, and sitting there for hours wondering what is going on. When shopping for a scope there are a few things that affect the price.

We have bought scopes from Tektronix and from Keysight, and for the most part they are about equal in capability. Both companies make models that are very similar so it's easy to compare them. Two very decent scopes that you might consider are the Tektronix DPO2024B and the Keysight DSOX2024A. They are both 200MHz bandwidth with four channels (even the model numbers are similar.) Both are available with options for triggering on embedded systems communications protocols. Total cost for one of these is probably around $3,000 depending on what deals you can get from the vendor.

If you want to go a bit cheaper, Tektronix (and other companies) makes a line of less expensive scopes that can still be very useful. However they usually don't have any ability to do the more advance triggering as described above.

Power Supply

A lot of small projects can be done using a wall-wart type of power supply but for more serious work a good multi-output bench supply is preferred. To select a bench power supply, you need to decide on what voltage and current ranges are required and how many outputs are needed. A single output supply that can supply just one voltage is cheaper than one with multiple independent outputs. However if you need multiple voltages it's probably cheaper to buy one triple output supply than three single output models.

A model that we have used and like is the Keithley 2230-30-1 triple output supply. Two of the output channels can be adjusted to a voltage from 0 to 30 volts and can supply 1.5 amps per channel. The third only goes from 0 to 6 volts but can provide 6 amps of current. The combination of these should be enough to power most projects.

These run about $1,000 so it probably only worth getting if you really need the capabiliies of it, or are sick of dealing with cheap alternatives.