Modern Demo For A Casio PB-700 Pocket Computer Plotter

August 13, 2023 by Chris Lott 9 Comments

[Fred] has a Casio PB-700 pocket calculator / computer, complete with the companion docking station featuring a four-color pen plotter, model FA-10, and a microcassette tape recorder, model CM-1. He really wanted to see what this plotter could do, but there were no demos that he could find. So despite only having one working pen, [Fred] took matters into his own hands and proceeded to make his own.

What if I made a program where I type what I want to draw and the PB-700 just draws it?

[Fred] succeeds, shoehorning several sub-projects into a single convoluted work flow: request an image from the PB-700 and after a long pause the plot emerges. The cute microcassette recorder is too much of a hassle, so he emulates the audio interface on a PC using a utility called casutil that reads and writes .wav files in PB-700 format. Much of his effort is spent figuring out how to request an image from Midjourney without being banned, but eventually comes up with a workable but shaky solution. The last steps are to convert the image into a line drawing, and then wrap up all those X-Y coordinates into a Basic program and send it back down to the PB-700 for plotting.

You can read more details in the PloTTY GitHub repository. There were several of these pocket computers with plotters coming out of Japan in the 1980s. In addition to this Casio, the Radio Shack TRS-80 PC-1 and PC-2 come to mind, which were re-branded versions of the Sharp PC-1211 and PC-1500 models. We wrote about them last year. This author had a PC-2 in 1985 and used it to plot antenna patterns at his desk, bypassing the IT department’s red tape. Have you ever used any of these pocket plotters? If so, let us know in the comments below. Thanks to [Altomare] for send us the tip.

Plotter Churns Out Labels With Roll Of Tape

September 3, 2022 by Danie Conradie 24 Comments

Like it or not, organizing your workspace from time to time is a necessary chore. Labels can go a long way towards taming the most unruly of benches, but writing them out by hand isn’t exactly ideal. Looking for something a bit neater, [sandy] built a simple pen plotter to write labels on a roll of tape.

The plotter uses the usual 3D printer components like steppers, drivers, belts, and rails. The tape holder is printed with flexible arms for a tight grip, and a servo is used to raise and lower the pen while writing.

The custom control board includes an Arduino Nano clone and a pair of stepper drivers, and an optional Bluetooth module and can be configured for a variety of machine control applications. A pair of Android apps are used to generate and send the G-code from a phone to the GRBL firmware loaded on the Arduino.

This seems to fall in the category of “entry-level” custom automation tools which help to save some time and effort on repetitive tasks without blowing the budget. We would include the various component tape cutters we’ve seen in this category, as well as smart build platform for manual PCB assembly

Purpose-Built Plotter Pitches In To Solve Wordblitz On Your Phone

July 23, 2022 by Dan Maloney No comments

It seems like most hackers have never played a game without at least wondering how to cheat at it. It’s not that we’re a dishonest lot, at least not as a rule. It’s more that most games hold less challenge for us than does figuring out how to reverse engineer the game’s mechanics. We don’t intend to cheat; it just sort of happens.

Or at least that’s the charitable way to look at such smartphone game cheats as this automated word-search puzzle solver. The game is Wordblitz, which is basically an implementation of classic Boggle along with extra features to release more dopamine and keep you playing. Not one to fall for that trick, [ghettobastler] whipped up a quick X-Y gantry from MDF using a laser cutter, added a stylus in the form of a cotton swab tipped with aluminum foil, and a vision system based on a simple web camera. The bed of the gantry has a capacitive plate so the stylus can operate the phone, along with a frame of ArUco fiducial marker to aid in locating the phone.

A Raspberry Pi handles the machine vision part of the process, which uses OpenCV to estimate the phone’s location and extract the current game tiles. The words in the game field are located by a solver that [ghetto] had previously written; a script then streams G-code to the plotter to peck out the answers at blazing speed, or at least faster than even [Peggy Hill] could manage. See the video below for a sample game being solved.

One word of warning if you choose to build this: [ghettobastler]’s puzzle-solving algorithm is based on a French dictionary, so you’ll have to re-teach it for other languages. But whatever language it’s in, this reminds us a bit of some of the Wordle solvers we’ve seen recently.

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A camera slider made from wood and recycled parts

Turning Old Plotter Parts Into A Smooth Camera Slider

April 7, 2022 by Robin Kearey 3 Comments

Taking apart old stuff and re-using the parts to make something new is how many hackers first got started in the world of mechanical and electronic engineering. But even after years working in industry we still get that tinge of excitement whenever someone offers us an old device “for parts”, and immediately begin to imagine the things we could build with the components inside.

So when [Victor Frost] was offered an old Cricut cutting plotter, he realized he could use its parts to create the camera slider he’d been planning to build. The plotter’s X stage, controlled by a stepper motor, was ideal for moving a camera platform back and forth. [Victor] wanted to build the entire thing in a “freehand” way, without making a detailed design or purchasing any new parts. So he dived into his parts bin and dug up an Arduino, a 16×2 LCD, some wires and buttons, and a few pieces of MDF.

The camera mount is simply a piece of steel that a GoPro’s magnetic mount can latch onto, but [Victor] keeps open the possibility of mounting a proper tripod ball head. The Arduino drives the stepper motor through an Adafruit Motor Shield, with a simple user interface running on the LCD. The user can set the desired end points and speed, and then run the camera back and forth as often as needed. In this way, the software follows the same “keep it simple” philosophy as the hardware design.

If you’re planning to build your own camera slider, [Victor]’s design should be easy to copy, if you happen to have an old cutting plotter. If not, you can try this simple yet well-engineered model. Want even more? Then check out this fancy multi-axis camera motion control rig.

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Servo Plotter Needs Nothing Exotic

January 5, 2022 by Al Williams 28 Comments

Although the widespread use of 3D printers has made things like linear bearings and leadscrews more common, you still can’t run down to your local big-box hardware store and get them. However, you can get drawer slides and any hobby shop can sell you some RC servos. That and an Arduino can make a simple and easy plotter. Just ask [JimRD]. You can also watch it do its thing in the video below.

Of course, servos aren’t usually what you use in a plotter. But the slides convert the rotation of the servo into linear motion. One servo for X and one for Y is all you need. Another microservo lifts the pen up and down using a hinge you could also get from a hardware store.

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Drawing Robot Creates Portraits Using Pen, Paper And Algorithms

October 25, 2021 by Robin Kearey 6 Comments

Although the market for hand-drawn portraits largely collapsed following the invention of photography, there’s something magical about watching an artist create a lifelike image using nothing but a pencil, some paper, and their fine motor skills. Watching a machine do the same is a similarly captivating experience, though often the end result is not so great. Trying to fix this deficiency, [Joris Wegner] and [Felix Fisgus] created the Pankraz Piktograph which seems to do a pretty good job at capturing faces. They were inspired by classic picture-drawing automatons, and made a 21st-century version to be used in museums or at events like trade shows.

The operation of the Piktograph is very simple: you stand in front of the machine, look into the camera and take a selfie. If you like what you see, the robot will then begin to draw your portrait on a piece of paper. It does this using two human-like arms which are made from aluminium and driven by two stepper motors. An ordinary ballpoint pen is held in a spring-loaded carrier, which provides just enough pen-to-paper pressure to reliably draw lines without lifting off or scratching the paper. We can’t help but be impressed with the overall look of the machine: with a sleek, powder-coated aluminium case and a stainless steel stand it’s a work of art by itself.

Inside, the Piktograph is powered by a Raspberry Pi 3, which runs a rather sophisticated algorithm to generate a vector image which doesn’t take too long to draw, but still results in a recognizable image of the subject. The makers’ thesis goes into quite some detail to explain the process, which uses Canny edge detection to create an outline drawing, then fills in the empty bits to create bright and dark areas. A certain amount of noise and wigglyness is added to the lines to give it a more “handmade” feel, and the resulting drawing is divided into continuous lines for efficient drawing by the plotter.

We’ve seen several types of specialized art robots before, capable of drawing portraits with a pen, painting them, or even using an Etch-a-Sketch, but [Joris] and [Felix]’s creation seems to win on speed, workmanship, and the quality of the end result. Video embedded after the break.
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Open Source Autopilot For Cheap Trolling Motors

September 24, 2021 by Danie Conradie 14 Comments

Quiet electric trolling motors are great for gliding into your favorite fishing spot but require constant correction if wind and water currents are at play. As an alternative to expensive commercial GPS-guided trolling motors, [AlexAsplund] created Vanchor, an open source system for adding autopilot to a cheap trolling motor.

To autonomously control an off-the-shelf trolling motor, [Alex] designed a 3D printed steering unit powered by a stepper motor to attach to the original transom mount over the motor’s vertical shaft. A collar screwed to the shaft locks the motor into the steering unit when the motor is lowered. The main controller is a Raspberry Pi, which hosts a WiFi hotspot and web server for control and configuration using a smartphone. Using navigation data from an e-compass sensor and a marine GPS chart plotter, it can hold position, travel in a specified direction, or follow a defined route. [Alex] is also planning to add the option of using a GPS module instead of a commercial plotter.

For an estimated total of $300, including the motor, this seems like a viable alternative to commercial systems. Of course, it might be possible to add even more features by integrating the open source ArduRover autopilot, as we’ve seen [rctestflight] do on multiple autonomous vessels. You can also build your own open source chart plotter using OpenCPN, which rivals commercial offerings.