Review: FriedCircuits USB Tester

Over the last decade or so, USB has somehow changed. It’s not just for connecting printers, keyboards, mice, and webcams any more. It’s not even just for stuff you would have plugged into a serial port. It’s a power outlet. If you want to charge your phone, plug it into a power outlet that can deliver up to 2.5 Watts. Unintended consequences, I guess. If you ever find yourself in 1995 again, go over to Intel and tell them to bump up the current limit.

Being a power outlet, having a device to measure current, voltage, power, and all the other intricacies of the what’s going on inside a USB cable would be neat. The USB Tester from Fried Circuits is that device.

DSC_0009The Fried Circuits USB tester isn’t so much a single device, but a small set of tools that allow you to probe everything going on inside a USB cable. In its simplest form, it’s just a board with a USB A connector at one end, a USB micro connector at the other, and breakouts for measuring current, voltage, the differential data signals, and that weird ID pin that’s useful if you’re working with USB chargers or OTG devices.

This breakout board also has two rows of five pins broken out. That’s for the USB Tester Backpack, which is really the heart of this device. This backpack features a microcontroller and a 128×64 resolution OLED display for current, voltage, and power monitoring, reading the voltage on the data lines, and graphing everything on the display. Everything you would ever want to know about a USB port – except for the actual bits being shoved through, of course – is right there on the display. Press the button on the side a few times, and whatever info you need will be presented in tall, very readable numbers.

The Entire Reason For Buying One

If you’re only going to use this to look at voltages, amps, and current flowing through a USB cable, you’re throwing your money away with this USB Tester. If simple, at-a-glance monitoring is what you need, you can hop on Amazon and get a USB current/voltage meter for $15. Even Adafruit has one for $7.50. If you only need to read the volts and amps for a USB device, your money is better spent elsewhere.

The Fried Circuits Java app.

The Fried Circuits USB tester does something none of these other USB meters can do. It can log all the data to a computer over USB.

In my initial review of the USB Tester for the Hackaday Store, the only ‘official’ option for recording data from the Tester to a computer was a Java app. The developer of the USB Tester, [Will], chose Java because of the ‘write once, run anywhere’ Sun and Oracle have been shoving down our throats for the last 20 years. In theory, Java was an excellent choice for a datalogging solution for the USB Tester.

In practice, however, it just didn’t work. By [Will]’s own admission, it was the first thing he’s ever done in Java, and I think he set some of the options in NetBeans wrong. I could not get the data logging app to run on my Windows 8 box, or my OS X box, or my Linux boxxen. The only way I could run this app was by digging out an old XP box. Apparently, [Will]’s copy of NetBeans was configured for Java 5 or something.

[Will] knew about this problem, and last month he officially teamed up with [Edouard Lafargue] of This is a platform for scientific instruments that runs in a Chrome App. The choice of running instrumentation in a Chrome app may seem odd, but this is apparently the new hotness; you can program an Arduino in a Chrome app, and there’s a lot of interesting stuff happening in this space.

You can try out the Chrome app right here, and with the USB Tester everything works as intended:

The app.

The app can do everything you would expect from a datalogging app. It will tell you the volts, amps, watts, mWh, and mAh of the device currently under test. There are pretty graphs, and everything can be downloaded to a computer for further analysis.

It might seem like cheating to review this device with a 3rd party app, but by [Will]’s own admission, there were problems with the Java-based logger, and the Chrome app works perfectly. There’s also the delicious irony that a Chrome app is more portable than one written in Java. I appreciate that.

Of course the USB Tester also outputs this data over a serial connection (in JSON format, too!). If you just want to connect this to a computer, solder up some wires to the TX and RX lines.


If you want a device that just tells you how many mA a USB device is sucking up, you don’t need this. You can buy something for less than $10 that will tell you that. If you’re developing some USB hardware, you’ll eventually want to characterize how much power your device is drawing and when it’s drawing that much power. This will require a data logging tool, and apart from cutting up a few USB cables and wiring it into an expensive power supply, you can’t do better than the Fried Circuits USB tester.

Review: Stickvise Needs a Place on Your Bench

Stickvise is a simple device for a simple problem. It holds a work piece while you work on it. Most obviously this means a PCB for soldering, but there’s a twist of versatility that will make it work for a wide range of needs. Being someone who has often used the roll-of-solder-to-hold-a-circuit-board-down trick, only to upset the apple cart when I run out solder, this is a great little tool to have within arm’s reach. For those that already have a PCB vise, how often do you need more than one? How rarely do you need something that large? And if you’re lucky enough to have a microscope for soldering this is a perfect fixture for moving a board to and from without adjusting the focus.

Details of the Design

Simplicity. This is three pieces of aluminum bar-stock, some steel rod, nylon jaws, two springs, and some fasteners. It all works extremely well. To load up a new circuit board I loosen the wing nut and squeeze the clamp shut. Hand tightening the nut doesn’t take much force and it hasn’t slipped for me at all despite moving it around the bench for several days. Once set, the board can be taken out and flipped over easily thanks to the springs.

The extensibility here is key. As it stands, the nylon jaws have a V-groove to hold a board. If you need to support much taller boards you can always put some standoffs between the aluminum and the nylon jaws.

stickvise-custom-jawsBetter yet is the ability to design jaws for your own needs. [Alex Rich], Stickvise’s creator, already has a number of STL files available so that you may print out your own. The “fingers” on the custom jaw shown here interlock with the ones on the opposite side. But my favorite is an articulated set of “third-hand” style jaws based off of the PCB probe jig [Anool] covered back in May. There are even plans to make a parametric STL file so that printing larger or taller jaws doesn’t require a CAD modeling session.

If the range of the vise is too narrow you can simply replace the center bar with a longer one (source yourself or purchase from [Alex]) — the fixed aluminum end is secured with a set screw. This can even be used as a type of stretcher by reversing the spring jaw. I couldn’t think of an application in my own shop for this but you never know.

Stickvise Roots

stickvise-hackaday-approvedIf you have an eagle eye you’ll have noticed the Jolly Wrencher with “Hackaday Approved” next to it on the Stickvise. When [Alex Rich] started refining his original design he posted about it as a project on It didn’t take long to grab our attention and, after tossing around the idea a bit we approached [Alex] about his plans for manufacturing and how Hackaday might figure into that. I love seeing hardware come to life like this; it puts an artisanal spin on the things I choose to have in my lab.



It’s so simple you could build it, but for me the production quality is well worth buying it instead. It’s simple and durable, with the ability to be specialized for a number of different purposes. I wish I had had it when populating the board I’ve been showing off in these pictures (the LayerOne Badge from this year). If you do any work with circuit boards at the bench the stickvise is a solid entry on your must-have-tools list.

The Stickvise is available in the Hackaday Store.

Review: DSLogic Logic Analyzer

Logic analyzers historically have been the heavy artillery in an engineer’s arsenal. For many of us, the name invokes mental images of large HP and Tektronix iron with real CRT screens. Logic connections were made through pods, with hundreds of leads weaving their way back to the test equipment. The logic analyzer came out when all else failed, when even a four channel scope wasn’t enough to figure out your problems. Setting them up was a pain – if you were lucky, the analyzer had a PC keyboard interface. If not, you were stuck typing your signal names into the front panel keyboard. Once setup though, logic analyzers were great at finding bugs. You can see things you’d never see with another tool – like a data bus slowly settling out after the read or write strobe.

There have been a number of USB based logic analyzers introduced in recent years, but they didn’t really catch on until Saleae released their “Logic” line of devices. Low cost, high-speed, and easy to use – these devices were perfect. They also inspired an army of clone devices based upon the same Cypress Semiconductor parts. DSLogic designed by DreamSource Labs, can be thought of as an open source evolution of the original Saleae device.

DSLogic appeared in 2013 as a Kickstarter campaign for an open source logic analyzer with an optional oscilloscope extension. I think it’s safe to say that they did well, raising $111,497 USD, more than 10 times their initial goal of $10,000 USD. These days both the DSLogic and the oscilloscope extension are available at The Hackaday Store. In this review we’re focusing on the logic analyzer portion of the tool. 

Click past the break for the full story!

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Review: uISP programmer for AVR

I got into AVR chips because they are easy to program, and that has become more and more true over the years with the ever-falling cost of programmers. But it’s pretty easy to make a mistake when burning the fuses on the chips and if you don’t have a proper programmer (my first programmer was a horrifyingly slow self-built DAPA cable) you’ll have a brick on your hands. This little board may be able to help in that situation. I gave the USB µISP a try this week. The half-stick-of-gum-sized board flashes firmware like a champ and includes a rescue pin for when you have clock source problems.

My full review is below. All technical information for the µISP can be found in the User’s guide. The board itself is now available to purchase in the Hackaday Store.

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Review: HUZZAH is the ESP8266 WiFi Setup You Need

A little board that adds WiFi to any project for a few hundreds of pennies has been all the rage for at least half a year. I am referring to the ESP8266 and this product is a marrige of one of those WiFi modules with the support hardware required to get it running. This week I’m reviewing the HUZZAH ESP8266 Breakout by Adafruit Industries.

If you saw the article [cnlohr] woite for us about direct programming this board you will know that a good chunk of that post covered what you need to do just to get the module into programming mode. This required adding a regulated 3.3V source, and a way to pull one of the pins to ground when resetting the power rail. Not only does the HUZZAH take care of that for you, it turns the non-breadboard friendly module into a DIP form factor while breaking out way more pins than the most common module offers. All of this and the price tag is just $9.95. Join me after the break for the complete run-down.

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Review: Transistor Tester

Amazon has been getting creepier and creepier lately with their recommendations.  Every time I log in, I’m presented with a list of new Blinky LEDs, Raspberry Pi accessories, Arduino shields, and the like. It’s as if they know me. Their customer database paid off when it recommended a $22 transistor / component tester. I’ve been seeing those testers around quite a bit lately. Curiosity got the better of me and my mouse found its way to the “Buy it now with one click” button. Two days later I had a “SainSmart Mega328 Transistor Tester Diode Triode Capacitance ESR Meter MOS/PNP/NPN L/C/R” in my hands.

I’m going to get the obvious out of the way. This thing is built cheap – as cheap as the factories can make it. My particular unit arrived with the LCD flapping in the breeze, hanging on by its flex cable. Fitting the LCD back into the acrylic backlight frame revealed a slightly worrisome twist in that same flex. Thankfully nothing was actually damaged, though I do want to give the flex cable some protection in the future. More on that later. The circuitry was open for all the world to see on the bottom of the tester. The heart of the unit is an ATmega328. Supporting it are a few transistors and a handful of passives.

I didn’t have huge expectations for the tester, but I hoped it would at least power up.  Hooking up a 9 volt battery and pressing the magic button brought the tester to life. Since I didn’t have anything in the socket, it quickly lit up and displayed its maker information – “”, and “By Efan & HaoQixin”, then it informed me that I had “No, unknown, or damaged part”.

I had a few resistors lying around the bench (doesn’t everyone?) so I put one in. The tester read it as 9881 ohms. Sure enough, it was a 10K 5% resistor.  Capacitors – ceramic disc, electrolytic, and surface mount all worked as well. The tester even provided ESR values. The real test would be a transistor. I pulled an old  2N2222 in a TO-18 metal can, and popped it in the tester. The damn thing worked – it showed the schematic symbol for an NPN transistor with Collector, Base, and Emitter connected to Pins 1,2,and 3 respectively. Flipping the pins around and re-testing worked as well. The tester showed hFe as 216, and forward voltage as 692 mV, both reasonable numbers for a 2N2222.

triacThe tester worked surprisingly well – it was able to correctly identify BJTs, FETs, even esoteric parts. The only thing it balked on was a linear voltage regulator, which showed up as two diodes. Regulators are a bit more than a simple device though, so I can’t blame the tester there.  The values returned were all reasonable as well. While I don’t have a calibrated lab to check against, the numbers lined up with my Fluke meter.

So what exactly is driving this little tester? There are about 20 versions of it on the market, all of them from China. 91make is a seller on, often referred to as “China’s ebay.” 91make’s front page features no less than 7 versions of the transistor tester, with various cases and LCDs. Some digging turned up the history on this device. It turns out the transistor tester is an open source hardware project (translated) originally created by [Markus Frejek], and built upon by [Karl-Heinz Kubbeler] and a number of others. The Subversion repository  for the project shows it is quite active, with the most recent check-in only a few hours ago. The project is also well documented. The English PDF is 103 pages, explaining theory of operation, the circuit itself, and the software. The document even explains some of the shortcomings of the Chinese versions of the tester, including using a zener diode where the original schematic calls for a precision 2.5V reference. Yes, it will work, but it won’t be as accurate as the original.

The devs also don’t officially support the clones which I can understand, considering the quality and changes in design each manufacturer is baking in to their own version. There is  a huge thread on the EEVblog forum covering these testers. Some can be modified to be closer to the official version. In fact, with an ISP tool the intrepid hacker can update the firmware to the current rev from [Karl-Heinz’s] repository.

So the final verdict on this tester is that it is a thumbs up with a small caveat. These testers are built down to a cost (and that cost is as close to zero as possible). They’re great for sorting parts, but they’re no substitute for a higher quality measuring device. I’d also love to see a version that supports the original developers.

Review: Printrbot Assembled Simple Metal

Hackaday is getting back into the swing of doing reviews, and with that comes reviews of the tool du jour, 3D printers. I have some reservations about reviewing a 3D printer; they’re a new technology, and what may be standard today could be hopelessly outdated in a few months time. Remember geared extruders? The new hotness is, apparently, direct drive extruders.

This is a review of the Printrbot Assembled Simple Metal. If you need any evidence that reviews of 3D printers have a shelf life, you only need to look at the Getting Started guides for this printer. When I bought my Simple Metal, the Printrbot recommended software stack was Slic3r and Repetier-Host. Barely three months later, Cura is now the Printrbot recommended software stack. If you think a simple change in software is inconsequential, check out these prints:

prusa parts
Prusa i3 X-carriages. Left sliced by Slic3r, right sliced by Cura

The print on the left was sliced with Slic3r. The print on the right was sliced with Cura. Notice the small teeth that grip the timing belt on each of these prints. With the Cura-sliced print, everything is fine. The Slic3r-sliced print is a complete failure, not of the machine, but the recommended software for the machine.

Therefore, if the goal of writing a review is to have a definitive opinion of a piece of equipment, a number of questions must be addressed. Since most 3D printing software is open source, should software be included in the review? Is the value proposition of a 3D printer simply a function of price to build volume (this seems to be the standard metric now), or are there intangibles? Should the review cover the quality of prints out of the box, or should the review only focus on print quality after dozens of hours of tweaking? I simply don’t know the answers to these questions, and I suspect you couldn’t get any two people to agree on the answers to these questions.

With that said, I feel I have used this printer enough to make a judgment call as to if this printer was a good buy.

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