Single board computers (SBC) are a great way to run some simple linux or Android software with hardware that is small and low power. Wiring up some peripherals like cameras, sensors, or any other custom electronics is the most common use for these little hardware gems so it makes sense that it should be easy to make nicely designed expansion boards for them.
I just created a few EAGLE libraries that are hosted by Element14 that captures these boards so they can be easy to expand upon, similar to the one I created for common Arduino boards. There is one for each the BeagleBone Black, RIoTboard, and Raspberry Pi Compute module. The libraries are designed for someone to either (a) start a custom board with a schematic symbol and package to represent the SBC or (b) document their project that is skywired into an existing board with just a symbol (by using the ‘EXT’ version, which has no package).
I think the Rpi Compute one will be the most popular. You can drop in a fully functioning linux box the size of DDR2 memory into any design in no time thanks to this library! Just watch out for some of the trace impedance specs as noted on the schematic.
I’ve been thinking about getting a new scope for a while. I currently run on a Tek TDS2024B 200mHz scope. It’s been a fine instrument for the last few years, but with the new mixed domain technology and my more regular use of digital technology, I thought now would be a good time to look at an upgrade.
Of course any equipment purchase needs to take it to the next level; like buying a new boat. So I have been reviewing the new Tek MDO3104 and how useful it is next to my TEK TDS2024B over at element14. Are you thinking about taking the scope plunge like I did?
These last couple of months CJ Gervasi and I have been reviewing the Fluke Connect system on element14.com. It’s a neat system where Fluke is using smartphones and tablets as an additional user interface. Note that they keep the standard user interface with knobs and buttons. But they added BluetoothLE in each of the instruments.
Users can not only read data wirelessly, but run datalogging applications, save measurements to their phone, video conference with colleagues while sharing live data on the screen, and organize recorded data by the job order or equipment.
It’s the first of its kind and I think they have done well out of the gate, even if there are a few bugs.
I’ve had a problem since moving into my new place that I can’t hear people knock at my front door. Sure I could get a doorbell at the hardware store, but those things stink. Instead, I thought I’d create a quick and simple Arduino and XBee based system to do it for me:
Doorbells are the 20th century version of today’s perpetually-interrupting cell phone. There you are, cooking a delicious dinner or reading a nice book when the doorbell rudely goes off in your ear. Sure, you’re glad to see whoever is at the door, but interruptions that chime can be so obnoxious. Needless to say, I do not have a doorbell.
The problem with the knocking system is that I usually can’t hear when someone knocks from my lab. I depend on Penny the Dog to alert me when someone is at the door. Except Penny sleeps most of the day. And then there are the delivery people (UPS/FEDEX) who can’t be bothered to knock, even if it is a next-day-early-AM shipment of parts from element14 that I am eagerly waiting for.
I decided that I’d create a project that solves all of my problems: a silent LED that flashes whenever someone approaches my door. It is based on a laser tripwire and will be able to run day or night, even in the bright Denver sun. And if the blinking LED is annoying, a simple button press disables the alert and resets the trigger.
Checking footprints in a PCB layout review with only the on-screen file can be a pain in the neck. There are many different measurements that need to be made for each individual part, and the mouse-based measurement tool can be somewhat obnoxious to get exactly on the edge of a pad.
There is a much faster way assuming one has all of the parts on hand: print out a to-scale paper prototype and place all of the components on the board. It is fast to setup, and visually inspecting each component takes about 30 seconds. There are, however a few tricks to be sure the printout is to scale. I wrote an article on Element14 with step-by-step instructions.
This past week I got a Fluke VT04, a Visual IR Thermometer. It is basically a $1,000 version of the very expensive IR cameras. While it doesn’t have the resolution or nice image viewing computer software, boy was it easy to use!
Still, given the amazing performance of the Mikron TH7515 from my Keithley days I can say you get what you pay for. The more precise uses for an IR camera can’t be used with the VT04, but the grunt measurements work just fine, making it a wonderful addition to an EE’s bench!
To read the review and learn how an IR camera can be used by someone who designs electronics,
Arduino is certainly the most popular method of getting info electronics, or at least embedded electronics. My BlueStamp Engineering students seem to gravitate to them when selecting their projects. But what about after the first few projects have been created with the Arduino? What if the designer wants to add a relay, or another LED to the board? Most people create a shield which allows them to plug in, but for simple projects I believe there is a better way: creating their own Arduino clone (AKA Derivative). This is where the designer modifies the public Arduino EAGLE PCB files to add their extra parts, and then makes their own board! It can save cost, space, and connectors! I go into more detail on my latest Element14 post:
Derivatives enjoy some significant design benefits over a shield. First, a single board is less than half the size and more robust than stacking an additional PCB on top of the purchased Arduino via headers. Second, it will be a cheaper solution than buying a stock Arduino and the custom shield PCB/parts. Finally, there is a lot to learn from starting with an existing PCB design and tweaking it. Not to mention the pride one would get from creating their own stand-alone design, even if it is attained by standing on the shoulders of giants.
Have you put together an Arduino-based circuit and looking to nicely (but easily) document it? Or perhaps you’re looking to create an Arduino Shield with EAGLE and want to start with the correct dimensions of the headers. Element14 has come to the rescue with the Arduino library of EAGLE parts for exactly that. There are two types of components in this library: the standard version with a PCB footprint showing the key connections and the ‘EXT version which has no PCB footprint.
The Standard version will be great for those looking to create a shield or want to somehow integrate the Arduino somewhere on another PCB. While the EXT version allows people to create a schematic that doesn’t bother with a PCB. In the EXT case, the user can create a PCB that is intended to connect to an Arduino via cables that are shown on the schematic, but isn’t included on the PCB.
Chris Gammell is an accomplished Electrical Engineer who currently works in electronics design by day and talks his head off about electronics by night to anyone that’ll listen. He co-hosts The Amp Hour podcast, writes on ChrisGammell.com, tweets more than most engineers, and is on the cusp of launching a new way to learn electronics: Contextual Electronics. I’ve known him from our time at Case Western Reserve University and two different jobs, and was able to catch up with him for an hour to discuss the direction he is taking, his experience, and a few lessons he’s learned along the way. Check it out on Element14!
Hardware engineers everywhere know how crrazy selecting parts can be. Especially when a part change needs to occur months after intiial part selection. Why was this part so special? What were the nuances of it again? Frame-it is a chrome extension that allows you to save a document or web page while taking notes as you go. Then everything is easily visible on your workbench. I wrote a quick article to describe the tool, it’s quirks, and how I’ve been able to use it…
…Given the importance of the part selection process, surely there are many different tools out there to help discover, keep track of part possibilities, and manage notes that one comes up with while searching. But sadly, the only tools that exist are the search tools provided by the part distributors. These are great for finding parts based on a wide array of specs, however each search is merely a way to find information. While some CAD tools like Cadence and Synopsys have solutions, they are expensive and generally only accesible to engineers at large companies. Beyond that, taking notes and remembering parts is a job usually ascribed to Excel or a paper notebook. That’s a great solution… for the year 1998! That’s where Frame-It steps in…