You can’t argue that Arduinos are extremely popular with the maker/hacker community. Some would say that there is certainly no shortage of projects to make using them. [Milen] thought otherwise and felt it was time to create an Arduino-based multimeter.
At the heart of this project is a common Arduino Uno. The additional parts were kept to a minimum in order to keep down the overall cost and project complexity. The finished product can measure voltage from 0-100v, amperage up to 500mA and resistance between 0-250 kohm. If you need to check for continuity, it can do that too.
All of the parts required to make the multimeter fit on a shield that plugs directly into the Arduino. Banana plugs allow for attaching test leads. The measurement values are displayed on an LCD screen and/or (if connected) to the Arduino IDE Serial Monitor. If only using the serial monitor, the LCD screen can be omitted to save a few bucks.
Continue reading “DIY Multimeter, Arduino Sold Seperately”
Fluke just issued a response to the impounding of multimeters headed for market in the United States. Yesterday SparkFun posted their story about US Customs officials seizing a shipment of 2000 multimeters because of trademark issues. The gist of the response is that this situation sucks and they want to do what they can to lessen the pain for those involved. Fluke is providing SparkFun with a shipment of genuine Fluke DMMs which they can sell to recoup their losses, or to donate. Of course SparkFun is planning to donate the meters to the maker community.
Anyone with a clue will have already noticed the problem with this solution. The impounded shipment of 2k meters will still be destroyed… eh. The waste is visceral. But good for Fluke for trying to do something positive.
Before we sign off let’s touch on the trademark issue for just a moment. We can’t really blame Fluke too much for this. The legal crux of the matter is you either defend your trademark in every case, or you don’t defend it at all. In this case it was the border agents defending the filing, but for ease of understanding we’ll not go into that. On the other hand, speaking in general business terms, the way things are set up it is advantageous to acquire a trademark specification that is as broad as possible because it helps to discourage competitors from coming to market. So trademark is good when it keep hucksters from trying to rip off consumers. But it is bad if applied too broadly as a way of defending a company’s market share.
Where does Fluke come down in all of this? Who knows. There is literally no right answer and that’s why the discussion around yesterday’s post was full of emphatic arguments. A Fluke meter is a cream-of-the-crop device and they have the right (and obligation) to ensure that reputation is not sullied. SparkFun serves a market that probably can’t afford a Fluke at this time but may some day in the future. And this is the reason we can feel okay about this outcome.
Check out this SparkFun Digital Multimeter. Does it make your blood boil to see them ripping off Fluke by using the color yellow? From SparkFun’s side of the story that’s exactly what’s happened here. They have a shipment of 2000 of these things stuck in customs. The trademark being infringed upon can be found in their article. Fluke owns the trademark on multimeters with a dark face and yellow border. Great. This seems like a wonderful idea, right up there with Apple owning tablets that are shaped like a piece of paper.
Okay, so if you’re not crying big fat tears for Fluke being taken advantage of in this way let’s talk about more immediate issues than fixing trademark, patent, copyright, and all of the other screw-the-little-guy type of laws (not that SparkFun is necessarily the little guy but you know what we mean). The DMMs sitting in a warehouse are costing SparkFun $150 per day. We believe they have no option of choosing a warehouse with a lower cost as we must be talking a pallet or two, right? The only two options they do have are shipping them back to China where they were manufactured, or having them destroyed. The former will cost more in re-import tariffs than the cost of the product, and the latter comes with a $150/hour disposal fee and no metric on which to judge how long it would actually take. We hate seeing this kind of waste, but sure enough 2000 DMMs are headed for the shredder in a couple of days.
We know you already have your flaming sword in hand, but simmer down for just a second. Fluke makes great products, ask anyone. And companies the world over defend their trademarks. Hopefully there will soon be a positive response from Fluke on this one. If you would like to politely encourage them to do the right thing we found Fluke’s Facebook page URL in the SparkFun comments thread. Both are worth browsing.
[Thanks Chris via Reddit]
Despite how useful multimeters are, there are a lot of limitations you just don’t think about because they’re the way electronic measurement has always been done. Want to measure voltage and current simultaneously? Better get two meters. Measuring something in a dangerous, inaccessible, or mobile place? You could rig up a camera system to show the meter’s display on a monitor, you know.
Mooshimeter is the better way of doing things. It’s a multichannel multimeter that communicates with your cell phone over a Bluetooth connection. With two channels. the Mooshimeter makes it easy to graph voltage against current to plot a beautiful IV curve on your smart phone. Being a wireless multimeter means you can stick the Mooshi inside a robot and get instantaneous feedback of how hard you’re driving your motors.
Far from being a two-trick pony, the Mooshimeter is actually a pretty good multimeter by itself. It can handle 600V and 10A with 24 bits of resolution. Here are the complete specs. The Mooshimeter is available for preorder here for $100 USD.
[Henryk Gasperowicz], the wizard of electrons who makes LEDs glow for no apparent reason, has put up another one of his troll physics circuits. We have no idea how he does it (he does say he’s using wireless energy transmission) so a few solution videos would be cool, [Henryk].
Altoids tins make great electronic enclosures, but how about designing your PCBs to fit mint and gum containers? Here’s a Trident USBASP, a tiny Tic Tac ISP thingy, and a Mentos USB to JTAG interface.
By the end of this week, the PS4 will be out, along with the new PS4 camera. It’s a great camera – 1280×800 at 60Hz – but unless someone develops a driver for it, it shall forever remain tethered to a PS4. Luckily, there’s a project to develop a PS4 camera driver, so if you have some USB 3.0 experience, give it a shot.
Multimeter teardowns? [David]’s got multimeter teardowns. It’s an HP 3455A, a huge bench top unit from the 80s. This is, or was, pro equipment and strange esoteric components definitely make a showing. ±0.01% resistors? Yep. Part two has some pics of the guts and a whole ton of logic.
The US Air Force Academy just moved their embedded systems course over to the MSP430. Course director [Capt Todd Branchflower] just put all the course materials online, with the notes, datasheets, and labs available on Github.
It’s pretty common to have at least a couple of meters around to measure different values of a circuit at the same time. Where [Emilio P.G. Ficara] ran into a problem was logging the data from both at once. These
Fluke meters have a serial-out, but his computer only has a single serial-in port. He cracked open one of the meters and figured out how to log data from both at the same time.
A lot of folks would look to a microcontroller to solve this problem. You use the chip to pull from each meter simultaneously and report back to a computer (or just dump the values onto an SD card). But this solution is a simple mechanical connector and a bit of creative programming. The way the serial output is set up on these meters they won’t interfere with each other as long as they’re read one at a time. [Emilio] wired them up as seen above, using his own software to manage the pins of the serial port. The example output he posted shows readings from the meters taken within about a tenth of second from each other. That should be good enough for most applications.
The old Fluke 8050a multimeter from the 80s is an awesome piece of lab equipment. It’s built like a tank, and thanks to the newer more portable models, this old meter is available for a pittance on eBay. [Ken] picked up a few of these meters and decided to give one of them a little upgrade – a 2.2″ 320×240 LCD display that is a vast improvement on the old stock seven-segment numerical display.
Inside the Fluke 8050a is a 40-pin DIP processor that handles all the computations inside the unit. [Ken]’s solution to tap into this processor was to take a 40-pin PIC microcontroller, bend some of the pins backwards, and use the remaining pins to drive the new LCD display. It’s actually somewhat brilliant in its simplicity and looks really cool to boot.
The rest of the circuitry consists of a level converter and a few wires going directly to the LCD display. [Ken] already has another Fluke 8050a on the bench waiting for a facelift and some plans for a few improvements that include a bar graph, histogram, and possibly even a touch display.