Tag Archives: analog

The perfect clock for analog aficionados

The Voltmeter Alarm Clock uses dual analog meters to tell time – one for hours and and one for minutes.

With the holiday shopping season officially underway, do you find yourself wondering what to get the electrical engineer in your life? How about a Voltmeter Alarm Clock?


Developed by Awkward Engineer, the device strikes an uncanny resemblance to an old-school analog voltmeter, except that it displays hours and minutes instead of volts and amps.

“Think of the clock as replacing digital LCDs with analog readouts. Instead of seeing 04:57, the hours meter will point to the 4 and the minutes meter will point to 57. Just like a clock rolls over at midnight and noon, the time meters rolls over zero,” its creators explain.

The stylish yet functional gadget initially appeared on Kickstarter last year, where it successfully garnered $36,000. The Massachusetts-based startup has since enhanced its original design with an alarm function, which is set using a toggle switch on its side.


Built around an ATtiny44, the Voltmeter Alarm Clock features an AM/PM indicator LED, an optional backlight on its display and mode-select knobs on top. Unlike its predecessor, the latest iteration is powered by USB, which can be plugged into a standard wall outlet using a “wall wart” adapter.

If you’re looking for an industrial-chic way to wake up in the morning, the Awkward Engineer team has the perfect thing for you. The Voltmeter Alarm Clock’s sheet metal exterior comes in two different colors — olive drab and grey — and expects to begin shipping next spring.


All tiny AVR parts in a spreadsheet

I just made a spreadsheet of all the tinyAVR parts. All my pals love the MCU selector guide, but I have a lot of analog dinosaur buddies that prefer a spreadsheet to a web-based interface. You can sort the data and this spreadsheet has the filter box on the columns, so you can sort out things you care about and exclude the things you don’t. The spreadsheet fits on a 24-inch display, and you can print it out on a single B-sized sheet and use it as an infographic.


This screenshot shows how all the tinyAVR parts will fit on one 11×17 ledger-sized or B-sized sheet of paper.

I started with an Excel dump of the selector guide after adding every single parameter to the search. I then took all the tinyAVR parts, and rearranged the columns, throwing out the irrelevant ones. I also combined the automotive parts with the basic parts. That added two columns for automotive temp and automotive Vcc range. Adding 2 columns to remove 13 rows seemed like a good deal. The part name links to the product page on our website.

I made a column for each package. That took a long time. Semiconductor companies think of a part as the silicon die, with the package being almost irrelevant. We systems folk know the package might be the most important thing. I tried to put the smaller packages on the left, with those big ol’ DIP (dual-inline plastic) parts on the right side. There is a second sheet in the spreadsheet that shows all the parts by number and there I put the package size, in mm. In both sheets, the package name links to the definition page on our website.


The second sheet of the spreadsheet shows all the tinyAVR parts by number. I put the exact package size on this page.

Besides the packages and package size, I also spent a long time getting pricing. My buddy Wayne Yamaguchi requested this, and he is absolutely right, price is the most important spec of any part, and I hate when it takes 5 clicks to find it. These prices are a bit sketchy. All I did was click on the “Buy” link and select a handful of parts from each family, and then looked at the Digi-Key price, in 1000s. I put in the highest and lowest of the few I selected, but this is by no means scientific or dispositive, as the lawyers would say. What I should do is put the price in the “Package” column, so you know what the package is and what price we charge, but many parts are in the same package but have two Vcc ranges, so there is no unique way to encode this and keep the spreadsheet on one printable page. Maybe I can blow out the second page to show every orderable part number and its price and specs. Always time to do it over, never time to do it right.

The major thing I want to add is the OrCAD 9.2 footprint name for the packages. I am afraid to do this now, since we have all been burned by narrow-DIP/wide-DIP and narrow -SOIC/wide-SOIC and what pin numbering to use on SOT parts, so that will have to wait for next time. If anyone has a proven definitive list of the OrCAD footprints, please let me know. paul.rako[yeah, the at sign]atmel.com

You can highlight all the parts and use the “Data>Sort” function to order them any way you want. I did it by Flash memory size and part name. You can also use the little filter boxes on each column to include or exclude, or even put in a logical range with equal or less than or all the other things. Its not exactly grep or regular expressions, but it can get the job done helping you to find the right part.


Excel filter boxes let you select just the parameters you care about.

I am told this spreadsheet works OK in Open Office/Libre. My pal Dave asked that any columns that are filtered be lit up red, but that takes a macro, and the VB macro may not work in Open Office, we are checking for that. Meanwhile, check there are 36 part families or that the little filter box does not have 3 pixels different to show the filter is on.


When you have filtered a column, it is almost impossible to tell, since the only indication is the icon makes this 3-pixel change.

Weasel weasel, CYA CYA, legal boilerplate—this is a hobby job, not an official Atmel document. If the selector guide had it wrong, it is wrong here too. I made my own mistakes too. And I already told you the pricing and the tiny1634 stuff was dicey. What I am hoping is that I can get some community support where you point out the errors, and tell me what to add. paul.rako[yeah, the at sign]atmel.com I also ask that you send this URL link to your pals, instead of just emailing the spreadsheet. That way the bosses will see you like this, and I can have the time to keep working on it.


If Hans Camenzind, the inventor of the 555 timer chip was still alive, he might have a copy of the tinyAVR spreadsheet up on his office wall. I miss Hans, at least he came to my Analog Aficionados party one year, before we lost him to the Grim Reaper.


ATmega32u4 MCU powers littleBits Arduino module

LittleBits has debuted a programmable ATmega32u4-powered Arduino at Heart Module. The new component will allow Makers to easily incorporate sketches into their littleBits circuits.

According to a LittleBits rep, the Arduino Module is capable of reading two types of input signals.

“The first is digital, which is a simple ‘on’ or ‘off’ signal. This is the type of signal you will get from a button or trigger. In the Arduino coding language, on is a HIGH signal and off is a LOW signal. All three inputs on the Arduino Module can read digital signals,” the rep explained.

“The other type of signal is an analog signal. Analog signals aren’t just ‘on’ or ‘off.’ They work like a dimmer switch or a volume knob. In the Arduino coding language, analog signals are given a value between 0 and 1023. If you connected a dimmer module to your Arduino and turn the knob up (clockwise), the value would slowly rise from 0 to 1023. The inputs on the Arduino module marked a0 and a1 both accept analog signals.”

As Engadget’s Jon Fingas notes, the programmable module gives Makers much more control over LittleBits’ existing modules, such as the oscillators in the Synth Kit.

“However, it also opens the door to interaction with your computer. Since the Arduino module has USB support built-in, you can create Etch-A-Sketches, Pong games and other programs that have LittleBits and your PC working in harmony,” said Fingas.

“[Plus], many existing Arduino projects should work with only a few slight tweaks to pin assignments.”

The stand-alone Arduino module can be snapped up for $36, although LittleBits is currently offering an $89 starter bundle that includes a total of 8 prototyping modules.

Interested in learning more? You can find additional information about the new LittleBits module here.

Video: PCB 201 with Atmel’s Paul Rako

In this Atmel Edge episode, Analog Aficionado Paul Rako demonstrates how to place a switching power supply on the same circuit board with analog and digital circuits.

“It’s a fairly high-level clever trick to lay out a switching power supply on a board that has analog and digital and some delicate circuits,” Rako explains.

“What did my two friends – Jon Dutra and Alan Martin – come up with? You use a top-side copper pour on your circuit board to make a local ground for your switching regulator. And then you just connect it at one place, at the bottom, at the ground reference of the output capacitor.”

To illustrate his point, Rako highlights a four-layer circuit board.

“So this is top, signal, then there’s ground, then there’s power plane, then there’s bottom signal. Design it four-layer. When you get that figured out, then you can spin it down to a two layer. A buck regulator, has an input voltage. Got an input capacitor. Then you’ve got a switch,” he continues.

“Usually it a FET transistor, or sometimes it’s inside the control IC. Here’s that control IC. Then you’ve got a catch diode, which causes a lot of problems. It gets hot. Sometimes it’s inside the IC. Sometimes it’s a synchronous. The basic thing with a switching regulator is this inductor. Then you’ve got an output capacitor. And always put those arrows and feathers on your circuit so people understand what’s coming in and what’s going out.”

As Rako notes, the inherent problem with a switching regulator is its fast-changing currents, di/dt.

“Those fast-changing create electromagnetic noise. If you let them run in the ground plane they’ll go out and affect other circuits on your PCB. So the trick is you pour a top-side copper pour,” he added.

Interested in learning more? Be sure to watch the video above for a full PCB 201 run-down.

Atmel-Arduino powers this hybrid clock

ECAL design student Pauline Saglio has created a unique series of three digital/analog hybrid clocks in an effort to meld the digital world with the analog act of winding a clock.

“Nowadays, time is everywhere, on our computers, on our phones, in the street; it has been so automated that the gestures relative to its reading have now changed,” Saglio told Wired. “In fact, we no longer have a permanent relationship with time but with the clock.”

According to Saglio, each of the three clocks is comprised of a touchscreen nestled into a box with a brass key sticking out of it. The screens remain blank until the user pulls, pushes or twists the key – prompting the display of time in the form of hand-drawn black and white animations. These minimalistic drawings fill the display for a minute or so before reverting to a blank screen.

Key project components include an Atmel-based Arduino board, potentiometer and Mac Mini.

“[These components] allow her to connect the physical action of rewinding to the digital animations. Three scripts interpret when the key is being turned, when it stops and when it’s returning to its original position,” explained Wired’s Liz Stinson. ” It’s a fairly technical process disguised by an analog appearance, which Saglio says is a recurring theme in her work.”

Indeed, Stinson said she often tries to conceal the technical aspects by introducing poetry.

“To make the public forget that it is a complicated work – to erase the boundary between them and me… I like this aspect of waiting for the time, and not have it like a gadget. I wanted to give time back the precious relationship it deserves,” she concluded.