Mini Wireless Thermal Printers Get Arduino Library (and MacOS App)

[Larry Bank]’s Arduino library to print text and graphics on BLE (Bluetooth Low Energy) thermal printers has some excellent features, and makes sending wireless print jobs to a number of common models about as easy as can be. These printers are small, inexpensive, and wireless. That’s a great mix that makes them attractive for projects that would benefit from printing out a hardcopy.

It’s not limited to simple default text, either. Fancier output can be done using Adafruit_GFX library-style fonts and options, which sends the formatted text as graphics. You can read all about what the library can do in this succinct list of concise functions.

But [Larry] hasn’t stopped there. While experimenting with microcontrollers and BLE thermal printers, he also wanted to explore talking to these printers from his Mac using BLE directly. Print2BLE is a MacOS application that allows dragging image files into the application’s window, and if the preview looks good, the print button makes it come out of the printer as a 1-bpp dithered image.

Small thermal printers make for neat projects, like this retrofitted Polaroid camera, and now that these little printers are both wireless and economical, things can only get easier with the help of a library like this. Of course, if that’s all starting to look a little too easy, one can always put the thermal back in thermal printing by using plasma, instead.

Coding A Custom Driver For The Adafruit Mini Thermal Printer

Thermal printers are cool… or, uh, warm actually. They use heat to make images, so they never need ink and they print on receipt rolls. The thermal printer available from Adafruit is a particularly tasty example, as it comes fully documented for the budding hacker. [Ed] is one such person, who set about writing his own driver to use the hardware with Linux on a Raspberry Pi.

The project came about as [Ed] didn’t like the halftone output from the standard Adafruit CUPS driver. Thus, a dithering-capable driver was needed instead. The first step of the project was to get dithering working via running such an algorithm into a custom driver, as well as to vary the heating time of the print head to gain greyscale capability. From there, the driver was integrated with CUPS and could be used with the Linux lp command. Finally, measures to deal with the paper running out were coded in as well.

It’s a fun dive into the nitty-gritty of talking to printers at the low level, something that few of us think about when printing concert tickets in a rush. There’s a lot that goes on to get a page to print successfully, and [Ed]’s work leaves us more respect for everything that goes on to get an image on the paper. The driver is available for keen tinkerers over at Github.

Meanwhile, consider a thermal printer for all your banner-printing needs.

You Won’t Believe How Much Tech Is Hiding In This Desk

Say what you will about office life: there were definitely some productivity perks, but the coffee is much better at home. Like many of us, [Pierre] has been working from home for the last year or so. And as much as he might enjoy spending so much time in his small Parisian apartment, it lacks many of the amenities of the office such as a scanner, printer, and, you know, a reasonable amount of space in which to work.

Inspired by another build, [Pierre] set out to build his dream desk that is maximum PC power in minimum space. It is chock full of easily-accessible cavities that hide everything you’d expect, plus a few things you don’t, like a flatbed scanner, a printer, a router, and a wireless charging pad. One cavity is dedicated to I/O, and another has three international power sockets. The only thing it doesn’t hide is the 22″ pen display that [Pierre] uses for sketching, signing documents, and occasionally as a second monitor.

A home-brew jig makes consistent dowel drilling much easier.

This desk may look like solid wood, but the top is a veneer that’s glued on to a custom-cut 1mm steel sheet. The inside frame is made of hardwood and so are the legs — one of them has a hidden channel for the only two cords that are even somewhat visible — the power and Ethernet cables. He joined all the frame pieces with dowel rods, and made a 3D-printed and metal-reinforced drilling jig to get the holes just right.

[Pierre] started this build by planning out the components and making meticulous notes about the dimensions of every piece. Then he sketched it and modelled it in FreeCAD to get all the cavities and cable runs correct and ensure good airflow through the desk. After that it was on to woodworking, metalworking, and PCB fab for relocated and hidden display controls and a custom-built amplifier.

It’s obvious that a lot of thought went in to this, and there’s a ton of work appreciate here, so clear off that inferior desk of yours and check out the build video after the break. Wish you had a PC desk? [Pierre] is seriously considering a Kickstarter if enough people show interest.

Are you into minimalism, but don’t want to build something of this magnitude? There’s more than one way to get there.

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ESP8266-Powered Receipt Printer Puts RESTful API On Dead Trees

Taking his digital information into the real-world, [Davide Gironi] has built his own note transcriber from a point-of-sale receipt printer and an ESP8266.

You’ve seen these receipt printers at the order window of restaurants. A server puts in an order from any of the machines throughout the restaurant and a paper summary spits out for the chef line to start in on (and even cuts itself off from the roll).  Why shouldn’t we have this convenience in our own lives?

The printer communicates using a variant of the Epson Standard Code for Printers, for which [Davide] has written a library and thankfully shared the code. Adding an ESP8266 using a couple voltage regulators and some passive components makes this wireless, except for power. It has all the fun bells and whistles to set up the WiFi credentials and once running, just push the button on the base and it’ll spit out your data.

But wait, where is that data coming from? The web-based settings page lets you configure a URI to the RESTful source of your choosing. (XKCD has one, don’t they?) It also lets you configure header, footer, error messages, and of course your company hacker logo.

One of our favorite receipt-printer moments was when Hackaday editor of yore [Eliot Phillips] brought a selfie receipt printer to Supercon. We couldn’t find any pictures of that one, so we’ll leave you with the excellent hack [Sam Zeloof] pulled off by cramming one of these into a Polaroid camera.

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Calendar Printer Makes You A Hard Copy On The Daily

We’re blessed to have cloud-based calendars that store all the relevant data on our hyper-busy lives for easy access anywhere and everywhere. However, sometimes a hard copy is nice for when you’re tired of looking at screens. In this vein, [lokthelok] produced a compact device that prints out your schedule on the daily.

The device uses an ESP32 to connect to WiFi, and then query Google Apps for a given user’s calendar details on a daily basis. After grabbing the data, it’s fed out to a thermal printer connected over serial at 9600 baud. As a twist, [lokthelok] has produced two versions of firmware for the project. The master version simply scrapes calendar data and outputs it neatly. The Useless version goes further, jumbling up appointments and printing them out of order. If you’ve got nothing on for the day, it will instead spool out the remainder of the thermal paper on the roll.

It’s a build that would make a handsome desk toy, though we suspect tossing out each day’s calendar could become tiresome after a while. Alternatively, consider a clock that highlights your upcoming events for you. Video after the break.

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Old Polaroid Gets A Pi And A Printer

There’s nothing like a little diversion project to clear the cobwebs — something to carry one through the summer doldrums and charge you up for the rest of the hacking year. At least that’s what we think was up with [Sam Zeloof]’s printing Polaroid retro-conversion project.

Normally occupied with the business of learning how to make semiconductors in his garage, or more recently working on his undergraduate degree in electrical engineering, [Sam], like many of us, found himself with time to spare this summer. In search of a simple, fun project that wouldn’t glaze over the eyes of people when he showed it off, he settled on a printing party camera. The guts are pretty standard fare: a Raspberry Pi and Pi cam, coupled with a thermal receipt printer for instant hardcopy. The donor camera was a Polaroid Pronto from eBay, in good shape on the outside and mostly complete on the inside. A Dremel took care of the latter, freeing up space occupied by all the plastic bits that held the film cartridge and running gear of the film handling system.

The surgery made enough room to squeeze in the Pi Zero and a LiPo battery pack, along with a buck converter. Adding in the receipt printer and its drive board and mounting the Pi cam presented some challenges, but everything fit without breaking the original look and feel of the Polaroid. The camera now produces low-res hardcopy instantly using a dithering algorithm, and store high-resolution images on an SD card for later download. As a bonus, [Sam] included a simulated time and date stamp in the lower corner of the saved images, like those that used to show up on film.

[Sam]’s camera looks like a ton of fun. We’ve seen other Polaroid conversions, including a stunning SX-70 digital upgrade, but this one shines for its simplicity and instant hardcopy.

[via Tom’s Hardware]

Print With Plasma!

Over the years there have been a variety of methods for a computer to commit its thoughts to paper. Be it a daisy wheel, a dot matrix, a laser, or an inkjet, we’ve all cursed at a recalcitrant printer. There’s another type of printer that maybe we don’t think of quite as often but is workhorse in a million cash registers and parking ticket machines: the thermal printer. These mechanisms can be readily found as surplus items and have made their way into more than one project here over the years. [HomoFaciens] has taken thermal printing a step further by building a plasma printer from scratch that makes use of the thermal paper.

A thermal printer does its job as its name suggests, by burning the image into the paper. It may not deliver the best quality print, but scores on not needing ink ribbons, cartridges, or toner. This DIY version uses an off-the-shelf battery-powered plasma lighter to do the job, mounted on a 3D printed XY printer mechanism driven by two stepper motors. Behind the scenes is an Arduino Uno, which receives its instructions via USB from a command-line program on a Linux box. It’s admitted that this is hardly the pinnacle of printing technology, but it does at least make for a fascinating project. You can see it in action in the video below the break.

This isn’t [HomoFaciens]’ first printer, we’re instantly reminded of this ink drop printer from a few years ago.

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