Raspberry Pi Cameras Stand In For Stereo Microscope

July 9, 2021 by Tom Nardi 9 Comments

Handling tiny surface mount components and inspecting PCBs is a lot easier with a nice stereo microscope, but because of their cost and bulk, most hobbyists have to do without. At best they might have a basic digital microscope, but with only one camera, they can only show a 2D image that’s not ideal for detail work.

The team behind [Stereo Ninja] hopes to improve on the situation by developing a stereoscopic vision system that puts tiny objects up on the big screen in three dimensions. Utilizing the Raspberry Pi Compute Module, a custom carrier board that enables the use of both MIPI CSI camera interfaces, and a 3D gaming monitor, their creation combines the capabilities of a traditional stereo microscope with the flexibility of a digital solution.

With two Raspberry Pi cameras suspended over the work area, and the addition of plenty of LED light, Stereo Ninja is able to generate the 3D image required by the monitor. While the camera’s don’t have the same magnification you’d get from a microscope, they’re good enough for enlarging SMD parts, and looking at a big screen monitor certainly beats hunching over the eyepiece of a traditional microscope. Especially if you’re trying to show something to a group of people, like at a hackerspace.

Of course, not everyone has a large 3D gaming monitor on their workbench. In fact, given how poorly the tech went over with consumers the last time it was pushed on us, we’d wager more hackers have stereo microscopes than 3D displays. Which is why the team’s next step is to have the Raspberry Pi generate the signals required by the shutter glasses, allowing Stereo Ninja to show a three dimensional image on 2D monitors; bringing this valuable capability to far larger audience than has previously been possible.

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Iron Becomes SMD Hot Plate

July 4, 2021 by Al Williams 20 Comments

Few things have changed our workshops more than surface mount components. In 1980 it would have been strange to see a hobby bench with a microscope, hot air equipment, tweezers, and all the other accouterments that are a necessity today. [Electronoobs] wanted a reflow hot plate and decided that he could repurpose a consumer laundry iron for the job. You can see the results in the video below.

Opening the iron revealed surprisingly simple circuitry, so the build has some additional parts along with a controller and an LCD, of course. The power requirement for the heating element is significant — 13 amps — so the plate uses a solid state relay to turn things on and off.

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Sub-mm Mechanical 3D Scanner With Encoders And String

July 1, 2021 by Danie Conradie 29 Comments

[Scott Rumschlag] wanted a way to precisely map interior spaces for remodeling projects, but did not want to deal with the massive datasets created by optical 3D scanning, and found the precision of the cost-effective optical tools lacking. Instead, he built a 3D cable measuring device that can be used to map by using a manual probe attached to a cable.

The cable is wound on a retractable spool, and passes over a pulley and through a carbon fiber tube mounted on a two-axis gimbal. There are a few commercial machines that use this mechanical approach, but [Scott] decided to build one himself after seeing the prices. The angle of rotation of each axis of the gimbal and the length of extended cable is measured with encoders, and in theory the relative coordinates of the probe can be calculated with simple geometry. However, for the level of precision [Scott] wanted, the devil is in the details. To determine the position of a point within 0.5 mm at a distance of 3 m, an angular resolution of less than 0.001° is required on the encoders. Mechanical encoders could add unnecessary drag, and magnetic encoders are not perfectly linear, so optical encoders were used. Many other factors can also introduce errors, like stretch and droop in the cable, stickiness of the bearings, perpendicularity of the gimbals axis and even the spring force created by the encoder wires. Each of these errors had to accounted for in the calculations. At first, [Scott] was using an Arduino Mega for the geometry calculations, but moved it to his laptop after he discovered the floating point precision of the Mega was not good.

[Scott] spend around 500 hours building and tuning the device, but the end result is really impressive. There are surprisingly few optical machines that can achieve this level of precision and accuracy, and they can be affected by factors like the reflectivity of an object.

If you do want to get into real 3D scanning, definitely take the time to read [Donal Papp]’s excellent guide to the practical aspects of the various technologies. Most of us already have a 3D scanner in our pocket in the form of a smartphone, which can be used for photogrammetry.

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AD409 Microscope Review

June 27, 2021 by Al Williams 20 Comments

It wasn’t that long ago that if you had an optical microscope in your electronics shop, you had a very well-supplied shop indeed. Today, though, a microscope is almost a necessity since parts have shrunk to flyspeck-size. [Maker Mashup] recently picked up an AD409 and posted a video review of the device that you can see below.

The microscope in question has a 10-inch screen so it is a step up from the usual cheap microscope we’ve seen on a lot of benches. Of course, that size comes at a price. The going rate for a new on is about $400.

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Custom 3D Printer Cart Hides Clever Features

June 26, 2021 by Tom Nardi 8 Comments

Even if you’ve got a decent sized workshop, there’s only so much stuff you can have sitting on the bench at one time. That’s why [Eric Strebel], ever the prolific maker, decided to build this slick cart for his fairly bulky Ultimaker 3 Extended printer. (Video, embedded below.) While the cart is obviously designed to match the aesthetics of the Ultimaker, the video below is sure to have some useful tips and tricks no matter which printer or tool you’re looking to cart around the shop in style.

[Eric] made a second video on sketching out the design.

On the surface this might look like a pretty standard rolling cart, and admittedly, at least half of the video is a bit more New Yankee Workshop than something we’d usually be interested in here on Hackaday. But [Eric] has built a number of neat little details into the cart that we think are worth mentally filing away for future projects.

For example, we really liked his use of magnets to hold the plastic totes in place, especially his method of letting the magnets align themselves first before locking everything down with screws and hot glue. The integrated uninterruptible power supply is also a nice touch, as it not only helps protect your prints in the event of a power outage, but means you could even move the cart around (very carefully…) as the printer does its thing.

But perhaps the most interesting element of the cart is that [Eric] has relocated the Ultimaker’s NFC sensors from the back of the printer and into the cart itself. This allows the printer to still read the NFC chip built into the rolls of Ultimaker filament, even when they’re locked safely away from humidity in a sealed box.

Now all you’ve got to do is apply for the loan it will take to pay for all of the MDF you’ll need to build your own version. At this point, we wouldn’t be surprised if encasing your 3D printer in metal would end up being cheaper than using wood.

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Raspberry Pi Pico Oscilloscope

June 26, 2021 by Danie Conradie 47 Comments

As you dive deeper into the world of electronics, a good oscilloscope quickly is an indispensable tool. However, for many use cases where you’re debugging low voltage, low speed circuits, that expensive oscilloscope is using only a fraction of its capabilities. As a minimalist alternative for these use cases [fhdm-dev] created Scoppy, a combination of firmware for the Raspberry Pi Pico and an Android app to create a functional oscilloscope.

As you would expect, the specifications are rather limited, capturing a maximum of 100 kpts at a speed of 500 kS/s shared between the two channels. Without some additional front end circuitry to protect the Pico, the input voltage is limited to 0-3.3 V. Neither the app nor the firmware is open source, and getting access to the second channel and removing ads requires a ~$3 in-app purchase. Even so, we can still think of plenty of practical uses for a ~$7 oscilloscope. If you do decide to add some front-end circuitry to change to voltage range, you can set them in the app, and switch between them by pulling certain GPIO pins high or low. The app has most of the basic oscilloscope features covered, continuous and single shot capture, adjustable trigger settings and a scalable waveform display.

Simple, cheap oscilloscopes like these have their place, but you start to understand why the “real” ones are so expensive when you see what goes into developing a high performance oscilloscope.

Silicon Jumpers Make This Wire-Free Breadboard Programmable

June 23, 2021 by Dan Maloney 23 Comments

There’s no doubting the utility of the trusty solderless breadboard, but you have to admit they’re less than perfect. They’re not ideal for certain types of circuits, of course, but that’s less of a problem than those jumper wires. The careless will end up with their components hopeless tangled in a rat’s nest of jumpers, while the fastidious will spend far more time making the jumpers neat and tidy than actually prototyping the circuit itself. What to do?

One way to crack this nut is to make the solderless breadboard jumperless, too. That’s the idea behind “breadWare” a work-in-progress undertaken by [Kevin Santo Cappuccio]. The idea is to adapt a standard breadboard so that connections between arbitrary pairs of common contact strips — plus the power rails — can be made in software. The trick behind this is a matrix of analog CMOS switch chips, specifically the MT8816AP. Each chip’s 128 crosspoint switches can handle up ± 12 volts, so there are plenty of circuits that can use these programmable silicon jumpers.

[Kevin] is currently on version 0.2, which is sized to fit under a solderless breadboard and make a compact package. He shared details on how he’s connecting to the breadboard contacts, and it looks like a painful process: pull out the contact, cut a small tab at the gutter-end, and bend it down so it forms a lead for a through-hole in the PCB. It seems like a lot of work, and there must be a better way; [Kevin] is clearly open to suggestions.

While we’ve seen crosspoint switching used to augment solderless breadboarding before, we find this project pleasing in its simplicity. The thought of tossing out all those jumpers is certainly tempting.