Scanning Receipts Proves Trickier Than Anticipated

April 21, 2022 by Tom Nardi 25 Comments

It’s one of those things that certainly sounds simple enough: take a picture of a receipt, run it through optical character recognition (OCR), and send the resulting information to whatever expense-tracking website or software you wish. There are companies that offer such a service, so it can’t be too difficult to replicate on your own…right?

That’s what [Marcel Robitaille] thought when he set out to create his homebrew “Receipt Ingestion” system, anyway. But in reality it took so much time to troubleshoot and implement that he says it would have been faster to just enter in all his receipts by hand. We’re happy he stuck with it though, otherwise you wouldn’t be reading about it on Hackaday, and we wouldn’t be able to learn anything from the detailed account he’s provided.

It only took an evening to hack together a rough demo, and the initial results were very promising. The code could detect the edges of the receipt, rotate the captured image appropriately, and then pull out the critical information such as date, total amount, business name, etc. He was then able to decipher the API for Splitwise, an online service for splitting bills, by capturing the data sent by his browser while adding a new bill. With this information, writing up some Python code to push his captured data into the service was trivial. So far, so good.

But like so many horror films that begin with a happy family starting a new life in a beautiful home, there was a monster lurking in the shadows. It’s one thing to capture data from perfectly clean and flat receipts, but quite another to get any useful info out of one that spent half the day crumpled up in your back pocket. The promising proof of concept that worked a treat under controlled conditions failed completely in the real-world, with [Marcel] reporting that only 1 in 5 receipts he tried to scan actually went through.

In the end, [Marcel] realized that the best way to handle the unreliable condition of the receipts was to focus on a different object in the image. He came up with a QR code marker that he could put on the table with the receipt to be scanned, which his software can use as a known point of reference. This greatly improves the reliability of the image rotation and transformation, which in turn makes the OCR more reliable. It also makes it much easier to tell which images need to be scanned — if there’s no QR code found, the software just skips that shot and keeps looking.

The unique challenges of digitizing large amounts of printed content using OCR makes for some fascinating problem solving, and we’re glad [Marcel] shared this particular story with us. While there’s still some edge cases that need chasing down, he’s using the software on a nearly daily basis, and has posted it up on GitHub for anyone who might wish to build on his efforts.

OLED Display Kicks Knob Up Several Accurate Notches

April 19, 2022 by Tom Nardi 9 Comments

As far as input devices go, the potentiometer is pretty straightforward: turn it left, turn it right, and you’ve pretty much seen all there is to see. For many applications that’s all you need, but we can certainly improve on the experience with modern technology. Enter this promising project from [upir] that pairs a common potentiometer with a cheap OLED display to make for a considerably more engaging user experience.

To save time, the code is fine tuned in a simulator.

The basic idea is to mount the display over the potentiometer knob so you can show useful information such a label that shows what it does, and a readout of the currently detected value. But you’ll likely want to show where the knob is currently set within the range of possible values as well, and that’s where things get interesting.

In the video after the break, [upir] spends a considerable amount of time explaining the math behind details like the scrolling tick marks. The nearly 45 minute long video wraps up with some optimization, as getting the display to move along with the knob in real-time on an Arduino UNO took a bit of extra effort. The final result looks great, and promises to be a relatively cheap way to add an elegant and functional bit of flair to an otherwise basic knob.

With the code and this extensive demonstration of how it all works, adding a similar capability to your next knob-equipped gadget shouldn’t be too much of a challenge. Perhaps it could even be combined with the OLED VU meters we’ve covered previously. Be sure to let us know if you end up using this technique, as we’d love to see it in action.

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Vintage Computer Festival East Is This Weekend

April 18, 2022 by Tom Nardi 1 Comment

This weekend the InfoAge Science and History Museum in Wall, New Jersey will once again play host to the Vintage Computer Festival East — the annual can’t-miss event for anyone who has even a passing interest in the weird and wonderful machines that paved the way for the supercomputers we now all carry around in our pockets. Ticket holders will have access to a program absolutely jam packed with workshops, talks, and exhibits that center around the dual themes of “Women in Computing” and “Computers for the Masses”, plus a consignment and vendor area that almost guarantees you’ll be going home a little poorer than when you got there. But hey, at least you’ll have some new toys to play with.

For those that can’t make the pilgrimage to the tropical wonderland that is the Jersey Shore in April, all three days of the Festival will be live-streamed to the VCF YouTube page. There’s even an official Discord server where you can chat with other remote attendees. We’re glad to see more events adopting a hybrid approach after two years of COVID-19 lockdown, as it gives the far-flung a chance to participate in something they would otherwise miss completely. That said, there’s no virtual replacement for the experience of browsing the exhibits and consignment areas, so if it’s at all possible we recommend you get yourself to InfoAge for at least one of the days.

Incidentally, don’t worry if you’ve got the sneaking feeling that it hasn’t been anywhere near a year since the last time the VCF descended on Wall Township. The 2021 Festival got pushed to October because of the lingering plague, but rather than permanently change the date going forward, the 2022 Festival has returned to its traditional season. Of course that means the wait until VCF 2023 will seem unusually long after this double-shot, so here’s hoping we see another swap meet at the InfoAge campus before the end of the year.

The 2022 Hackaday Prize Hack Chat Kicks Things Off

April 15, 2022 by Tom Nardi No comments

The 2022 Hackaday Prize is on, and we’ve already seen some incredible submissions by folks who believe their idea just might have what it takes to make the world a better place. But as with all contests, it’s good to understand all the rules before you get too involved. We promise nothing’s hidden in the fine print, but we certainly don’t fault anyone who wants to make sure.

Which is why Majenta Strongheart, Head of Design and Partnerships at our parent company Supplyframe, stopped by this week’s Hack Chat to answer any and all questions the community had about this global hardware design challenge. A lot of ground was covered in an hour, with Majenta making sure everyone’s questions and concerns were addressed to their satisfaction. After all, with a residency at the Supplyframe DesignLab and a total of $125,000 in prize money up for grabs, we want to make sure everyone’s got the facts straight.

So what burning questions did the Hackaday community have about this year’s Prize? Several people wanted to know more about the themes of sustainability, circularity, and climate crisis resiliency. For example, what exactly does circularity mean in this context? While Challenge #2 “Reuse, Recycle, Revamp” most clearly exemplifies the idea, Majenta explained that this time around the judges will be giving particular consideration to ideas that limit the extraction of raw materials and the production of waste.

For a practical example, 2022 Hackaday Prize judge James Newton pointed to the direct granule extruder designed by Norbert Heinz. The project, which took 5th place last year, allows waste plastic to easily be repurposed in a desktop 3D printer. This includes objects which the printer itself produced, but for whatever reason, are no longer desired or needed. This “life-cycle” for printed objects, wherein the same plastic can be printed over and over again into new objects, is a perfect encapsulation of circularity within the context of this year’s prize.

Others were looking for clarification on the contest rules. Specifically, there was some confusion about entering existing projects into the competition. Did it have to be a completely new idea? What if you’d already been working on the project for years, but had never shown it publicly before? Not to worry — existing projects can absolutely be entered into the 2022 Hackaday Prize. In fact, even if the project had already been entered into the Hackaday Prize previously, it’s still fair game.

But there is an important caveat: to be eligible for this year’s Prize, the project MUST be documented on a new Hackaday.io page. Additionally, if it’s a project that has previously been entered into a Hackaday contest, you’ll have to show that it is “significantly different from when previously entered and show meaningful development during the course of the Contest“, as stated in the official rules. In layman’s terms, it means that anyone who tries to submit and old and outdated Hackaday.io page into the competition will find their entry disqualified.

Towards the end of the Chat, Erin Kennedy, a Hackaday Prize veteran that readers may know better as “Erin RobotGrrl” brought up the subject of mentors. In previous years, hardware luminaries like Andrew “Bunnie” Huang and Mitch Altman were made available to offer advice and guidance to the individuals and teams behind the Prize entries. While very proud of this effort, Majenta explained that at least for now, Mentor Sessions are on hold until that aspect of the program can be retooled. The main issue is figuring out the logistics involved; planing video calls between several groups of busy folks is just as tricky as it sounds. That said, bringing the Mentor Sessions back for 2022 isn’t completely out of the question if there’s enough interest from the competitors.

We appreciate Majenta taking the time to directly answer questions from the community, and hope that those who had their questions or concerns addressed during the Chat will ultimately decide to toss their hat into the ring. With a worthy goal and plenty of opportunities to win, we sincerely want to see as many people as possible get their entries in before the October 16th deadline. If you’re ready to take the next step, head over to the Contest page and show us what you’ve got.

The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers connect in a fun and informal way, but if you can’t make it live, these overview posts as well as the transcripts posted to Hackaday.io make sure you don’t miss out.

Hackaday Podcast 164: Vintage NASA Soldering, Mouse Bites, ATTiny85 Graphics, And PVC Pontoons

April 15, 2022 by Tom Nardi 1 Comment

Join Hackaday Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi as they review the most interesting hacks and stories of the previous week. This time we’ll start things off by talking about the return of in-person events, and go over several major conventions and festivals that you should add to your calendar now. Then we’ll look at a NASA training film from the Space Race, an interesting radio-controlled quirk that Tesla has built into their cars for some reason, a very promising autonomous boat platform, and some high performance visuals generated by an ATtiny85. Stick around to find out what happens with an interplanetary probe looses its ride to space, and why the best new enclosure for your Raspberry Pi 4 might be a surveillance camera.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments below!

Direct Download

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Warm Up Your Extruders, RepRap Festivals Are Back

April 12, 2022 by Tom Nardi 5 Comments

Like pretty much every other large gathering, the Midwest and East Coast RepRap Festivals had to be put on hold during the height of the COVID-19 pandemic. But now that the United States is cautiously returning to something that looks a lot like normal, both Festivals have now confirmed they will be back to full-scale live events for 2022.

After experimenting with a virtual event and a scaled-down show in 2021, the Midwest RepRap Festival (MRRF) will be returning to the Elkhart County 4H Fairgrounds in Goshen, Indiana from June 24th to the 26th. No tickets will be required for attendees or exhibitors, everyone is welcome to just show up and have a good time. There will however be sponsorship opportunities for anyone who wants to support this long-running event.

Summer already booked up? In that case, the East Coast RepRap Festival (ERRF) will be taking place from October 8th to the 9th at the APG Federal Credit Union Arena in Bel Air, Maryland. Tickets cost $10 for both exhibitors and attendees, though anyone under 17 gets in for free. Even though ERRF only confirmed their 2022 plans recently, it looks like there are only a few sponsor spots still left open.

Hackaday has attended both events in the past, and we’ve always come back blown away by the incredible variety of printers, projects, and products on display. It seems like there wouldn’t be that many different ways to show off melted plastic, but trust us, these folks always manage to surprise you. Given the amount of time that’s passed since either event was able to operate at normal capacity, we predict these 2022 Festivals are going to be smash hits that you won’t want to miss if you’re even remotely interested in 3D printing.

Trenton Computer Festival Makes YouTube Debut

April 11, 2022 by Tom Nardi 9 Comments

While it doesn’t have the recognition of DEF CON or even HOPE, the Trenton Computer Festival (TCF) holds the record for the longest continually running computer convention, dating all the way back to 1976. TCF has offered vendor spaces, a swap meet, workshops, and keynote talks for almost as long as the personal computer has existed. But until now, all that knowledge was only available to those in the Northeast US that were willing to follow the itinerant event as its bounced between venues over the decades.

Or at least, that used to be the case. Like many events, TCF was forced to go virtual during the COVID-19 pandemic, which meant for the first time all the talks were actually recorded. Over the weekend, the organizers announced that all of the talks and demonstrations from 2020 and 2021 had been uploaded to a new YouTube channel, opening them up to a global audience.

Two years might not sound like much, especially given the fact that there’s still 40+ years unaccounted for. But thanks to the incredible amount of content that is squeezed into each year’s event, the TCF YouTube channel is currently playing host to more than 80 presentations that run the gamut from live musical performances to deep-dives on the Apollo Guidance Computer and quantum computing. Whatever you’re interests happen to be, there’s a good chance you’ll find a presentation or two that talks about it in this impressive collection.

When we made our last visit to this legendary convention, our only real complaint was the fact that none of the presentations were being recorded. With over 40 talks crammed into a six hour event, attendees couldn’t hope but to see more than a fraction of what was on the schedule. The nature of going virtual obviously made it much easier to preserve all this incredible content for later viewing, but it’s unclear if the organizers will be able to maintain that momentum in 2023 when it’s expected TCF will once again be in-person.