This year Denver hosted the 2017 Open Source Hardware Summit. It’s a one-day seminar with talks, demos, and a couple of drinks. The day after the official show Sparkfun and Aleph Objects hosted tours of their facilities. The combination of events made for a fantastic immersion into open source hardware.
There were many talks and demos setup during the summit. Here are three that caught my attention. Please note, this is not to rate or judge the quality of anyone’s work. Simply, a couple of weeks later these are the three talks that stuck with me.
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Previously, I wrote up a hands-on with the PicoScope 2204A. At the time I only spent a few minutes with the device. I used it to “debug” an I2C bus between an Arduino and OLED screen. Since that initial hands-on, I’ve used the PicoScope in my lab. Most notably, I hosted another “hands-on” via an AddOhms Live Stream. I used it for another live stream where I talked about op-amps. Unfortunately, the video isn’t watchable due to some technical difficulties.
However, both of those activities plus debugging a new project I’m working on, gave me a chance to understand this humble USB-based oscilloscope. Now that I’ve held well over a month of bench time with it, I can say I am happy with the 2204A. If you’re looking for a low-cost, but fully featured oscilloscope, give the PicoScope 2204A a consideration. For more details on why I feel that way, click the button below to see my full write review on element14.
What are aluminum polymer capacitors? These are a solid type of capacitor that replaces the liquid electrolyte with a solid polymer material. Sometimes you might hear these capacitors called “organic aluminum.” Technically, they are still “electrolytic” capacitors. However, the colloquial term of “aluminum electrolytic” refers to the traditional wet electrolyte-based capacitors.
For me, the release of this video is bittersweet. It is one of my last projects before my departure from KEMET. However, I am excited to talk about aluminum polymer capacitors because they represent one of the “newer” technologies when it comes to capacitors.
Difference between Aluminum Polymer Capacitors and Aluminum Electrolytics
As mentioned, the key difference between the capacitor types is the electrolyte. In a traditional aluminum electrolytic, there is an electrolyte that connects the cathode plate of the capacitor to the cathode electrode. In a polymer capacitor, a solid conductive polymer material replaces the wet electrolyte. The most common polymer material is PEDOT. The use of this material provides an exceptionally low ESR which makes the capacitors can handle more ripple current. Also, because there is no electrolyte to “dry up” or “wear out,” the operational lifetime of these capacitors is much longer. Overall, aluminum polymer capacitors are an excellent alternative to traditional electrolytics.
Previously, I wrote a FleaFPGA Introduction. This board was about the size of an Arduino Uno with some GPIO pins, a VGA, USB, SD Card, PS2 Style Port, and a USB Host connector. At the time, the Lattice Mach XO2 provided the base logic. It found some success in the emulation community (*cough* x86 *cough*.) Unlike software emulators, the FPGA emulates the actual digital logic of classic computer ICs. Also known as ASICs.
Fast forward to today, well, this week. Valentin Angelovski is at it again, but this time, with a new and improved board the size of a Raspberry Pi Zero. He’s launched an Indiegogo Campaign for the FleaFPGA Ohm. For $45 (plus a bit for shipping) you can reserve your spot for when these start shipping early next year.
As you might have noticed, I don’t often promote or comment on crowdfunded projects. My experience with crowdfunded projects has not been positive. So what makes the FleaFPGA Ohm different? Well first, I know Valentin well. Granted distance has kept us from meeting face-to-face, we talk at least once a week on IRC. I’ve been eagerly watching his progress with the FleaFPGA Ohm. Second, this isn’t his first hardware project. He’s already sold many of the original FleaFPGA boards. While there is always a risk with crowdfunded campaigns, I think the risk here is minimal–and worthwhile.
If you’re interested in advancing your hardware hacking game, FPGAs are the next step. And I think the FleaFPGA Ohm is a serious option to consider. Since you might be new to FPGAs or Valetin’s projects, I sat down to interview him for this project. (Okay, it was Google Docs, but these questions and answers are real!)
Before continuing, in disclosure, I have backed this project. However, no other endorsement or paid promotion has happened. Below here are actual answers from Valentin to questions I asked (and had.)
The Zener diode is often used to create a reference voltage. In tutorials and even college texts, there are mentions of creating a Zener diode based regulator. The idea is that the Zener maintains a known voltage drop. The problem is that current matters. This post looks a quick Zener diode overview and shows what happened when I tried to power a microcontroller using a “Zener diode regulator.”
If you need a reason to be an Element 14 member, let me suggest their Road Test program. Companies partner with Element14 to get people to try out their gear. A couple of years ago I got a new microcontroller board. This week I received a new test instrument. Here’s my hands-on Picoscope 2204 review.
The scope is bus powered. With the BNCs and type-B USB connector, it is slightly larger than an external USB hard drive. There is not much weight to the device. It does not feel cheap, just lighter than I expected.
Getting the scope up and running is a breeze. Pico Tech included a CD (or DVD?) to install the software, but I could not find my drive to check it out. Software downloads from Pico Tech’s website work great. It looks like you can even download the software and use it in “Demo mode” if you are curious how it works.
Here are some ideas of what you can do with the humble voltage divider. This elementary circuit has a few inventive uses. To be upfront, one of these uses is NOT as a voltage regulator. If you need a voltage regulated, get a voltage regulator! At some point or another, I’ve built all five of these voltage divider circuits. For me, the voltage level shifter is the most common.
Arduino tends to call daughter cards shields, while the Raspberry Pi community calls them hats. The Pi Cap is a hat. It plugs into the GPIO header of a Raspberry Pi and provides 13 capacitive touch pads. There is a traditional push button, an LED, and a prototyping area. While the Pi Cap does consume all of the GPIO pins, several are broken out near the GPIO header.
Previously, I reviewed the smartphone DMM, Mooshimeter. It is a great meter. One feature I didn’t spend much time on in my review was the ability to graph. Some see it as an “oscilloscope alternative.” The past couple of weeks, I’ve been using Aeroscope. It is a Bluetooth-based oscilloscope about the size of an older active probe. The Aeroscope runs $199 direct from Aeroscope Labs. The question I address in this Aeroscope review: is it better to buy this, a USB-based, or standalone scope for about the same money. How does it measure up?
My Aeroscope review looks at the specifications, the App that runs it and breaks down the key features. Let’s probe deeper.