Hands-On Nvidia Jetson TX2: Fast Processing for Embedded Devices

The review embargo is finally over and we can share what we found in the Nvidia Jetson TX2. It’s fast. It’s very fast. While the intended use for the TX2 may be a bit niche for someone building one-off prototypes, there’s a lot of promise here for some very interesting applications.

Last week, Nvidia announced the Jetson TX2, a high-performance single board computer designed to be the brains of self-driving cars, selfie-snapping drones, Alexa-like bots for the privacy-minded, and other applications that require a lot of processing on a significant power budget.

This is the follow-up to the Nvidia Jetson TX1. Since the release of the TX1, Nvidia has made some great strides. Now we have Pascal GPUs, and there’s never been a better time to buy a graphics card. Deep learning is a hot topic that every new CS grad wants to get into, and that means racks filled with GPUs and CUDA cores. The Jetson TX1 and TX2 are Nvidia’s strike at embedded deep learningor devices that need a lot of processing power without sucking batteries dry.

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Pine64: The Un-Review

Even before the announcement and introduction of the Raspberry Pi 3, word of a few very powerful single board ARM Linux computers was flowing out of China. The hardware was there – powerful 64-bit ARM chips were available, all that was needed was a few engineers to put these chips on a board, a few marketing people, and a contract manufacturer.

One of the first of these 64-bit boards is the Pine64. Introduced to the world through a Kickstarter that netted $1.7 Million USD from 36,000 backers, the Pine64 is already extremely popular. The boards are beginning to land on the doorsteps and mailboxes of backers, and the initial impressions are showing up in the official forums and Kickstarter campaign comments.

I pledged $15 USD to the Pine64 Kickstarter, and received a board with 512MB of RAM, 4K HDMI, 10/100 Ethernet and a 1.2 GHz ARM Cortex A53 CPU in return. This post is not a review, as I can’t fully document the Pine64 experience. My initial impression? This is bad. This is pretty bad.

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Hacking Online Reviews

For this post, I want to return the word hacking to its nefarious definition. We prefer the kinder definition of a hacker as someone who creates or modifies things to fit some purpose or to improve its function. But a hacker can also be someone who breaks into computer systems or steals phone service or breaks encryption.

There are some “hacker battlefields” that are very visible. Protecting credit card numbers from hackers is a good example. But there are some subtle ones that many people don’t notice. For example, the battle for online reviews. You know, like on Amazon when you rate the soldering iron you bought and leave a note about how it works. That might seem like a strange place for hacking until you stop and think about why people do bad hacking.

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Review: Single Board 65C02 and 65C816 Computers

The 6502 is a classic piece of computing history. Versions of this CPU were found in everything from the Apple ][, to the Nintendo Entertainment System, and the Commodore 64. The history of the 6502 doesn’t end with video games; for the last forty years, this CPU has found its way into industrial equipment, medical devices, and everything else that doesn’t need to be redesigned every two years. Combine the longevity of the 6502 with the fact an entire generation of developers first cut their teeth on 6502 assembly, and you have the makings of a classic microprocessor that will, I’m sure, still be relevant in another forty years.

The cathedral of The 6502 is Western Design Center. For more than 35 years, WDC has been the home of 6502-related designs. Recently, WDC has been interested in the educational aspects of the 6502, with one of the VPs, [David Cramer], lending his time to an after-school club teaching opcodes.

The folks at WDC recently contacted me to see if I would give their hardware a close look, and after providing a few boards, this hardware proved to be both excellent. They’re great for educators adventurous enough to deviate from the Arduino, Processing, and Fritzing zeitgeist, and for anyone who wants to dip their toes into the world of 65xx development.

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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 wizkers.io. 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 Wizkers.io app.

The Wizkers.io 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: 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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Introductions: 3 new writers

We would like to introduce our new writers [Rachel Fee], [Greg Jacobs], and [Jacob Nahin]. They will be focusing on software reviews and tutorials in response to the daily requests for posts that don’t require that you be an electrical engineer to understand.

The Hack a Day community is growing very fast and we are happy to be a valued source of information to our readers.