Color Your World With This CNC Painting Robot

August 6, 2019 by Dan Maloney 16 Comments

Let’s say you’ve watched a few episodes of “The Joy of Painting” and you want your inner [Bob Ross] to break free. You get the requisite supplies for oil painting – don’t forget the alizarin crimson! – and start to apply paint to canvas, only to find your happy little trees are not so happy, and this whole painting thing is harder than it looks.

[Saint Bob] would certainly encourage you to stick with it, but if you have not the patience, a CNC painting robot might be a thing to build. The idea behind [John Opsahl]’s “If Then Paint” is not so much to be creative, but to replicate digital images in paint. Currently in the proof-of-concept phase, If Then Paint appears to have two main components: the paint management system, with syringe pumps to squeeze out different paints to achieve just the right color, and the applicator itself, a formidable six-axis device that supports tool changes by using different brushes chucked up into separate hand drill chucks. The extra axes at the head will allow control of how the brush is presented to the canvas, and also allow for cleaning the brush between colors. The videos below show two of the many ways [John] is exploring to clean the brushes, but sadly neither is as exciting as the correct [Bob Ross] method.

It looks like If Then Paint has a ways to go yet, but we’re impressed by some of the painting it has produced already. This is just the kind of project we like to see in the 2019 Hackaday Prize – thought out, great documentation, and a lot of fun.

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Supercap Drink Coasters Are The Life Of The Party

August 5, 2019 by Tom Nardi 28 Comments

You’ve probably seen multicolored flashing LEDs embedded into clear plastic cups or coasters before, they’re quite commonly used in fancy restaurants that also feature animatronic characters and a gift shop on the way out. But have you ever wondered about the logistics of maintaining such devices? When the anthropomorphic rodent shuts down for the night, you’re going to want to clean all those blinking doodads; but any opening to connect a charger or insert a battery is just a leak waiting to happen.

[Scott Clandinin] has come up with a solution to this problem that’s equal parts brilliant simplicity and unabashed overengineering. Using wireless charging and supercapacitors, he’s developing an LED coaster that can be hermetically sealed in clear resin.

With no plugs to connect or batteries to change, these coasters can be permanently encapsulated with no ill effects. Granted the supercapacitors will degrade with time and eventually won’t hold a charge for as long, but even the most conservative estimates would have these coasters still partying in a decade.

For his prototype version [Scott] has put together a simple charging base, but we imagine in a full deployment such devices could be charged with induction coils built into a bar or table. While the energy consumption could potentially be a showstopper, we’d love to see a future version that integrates a radio receiver. Then the coasters could double as pagers to let diners know their table is ready.

While this device is obviously much thicker than a traditional coaster, it looks fairly reasonable even at this early stage. We like the concentric design that puts the coil inside the PCB, and wonder if similar cutouts couldn’t be used to get the twin 15F supercapacitors and charging module hunkered down just a few millimeters more. The 2019 Hackaday Prize is all about evolving an idea into a design suitable for production, and those are the sort of incremental improvements that the judges will certainly be keeping an eye out for.

Bringing Pro-Level Data Recording To RC Racing

August 4, 2019 by Tom Nardi 7 Comments

We’re all familiar with the “Black Box” used on commercial aircraft, the flight data recorder which captures the minutia of each and every flight on the off-chance that it’s needed in the event of an accident. But even in less dire circumstances, the complete record of the aircraft’s performance versus what was commanded of it by the pilot can be used to fine tune performance or detect faults before they become serious.

As a data engineer for professional motorsports, [Jussi Luopajärvi] knows similar recorders can be just as useful for vehicles stuck here on terra firma. His entry into the 2019 Hackaday Prize, TestLogger, aims to bring that same kind of technology to the world of RC racing. The gadget allows the driver to easily record a wealth of data about the vehicle during races, giving them valuable insight into the vehicle’s performance.

So what kind of variables are there to record on a 1/8th or 1/12th scale car? Don’t be fooled by their diminutive wheelbases, the modern RC car relies on an impressive amount of technical wizardry that benefits from a close eye.

Right now, [Jussi] says TestLogger can record not only obvious elements like battery level and throttle, but also more esoteric variables such as steering input, individual drive wheel speed, angular velocity, and even g-force in three dimensions. There’s also support for a trackside IR beacon that allows TestLogger to record lap times.

All of the data is stored on TestLogger’s SD card in standard CSV files, which makes it easy for us hacker types to parse and analyze. But for those who are more interested in driving than delimiting, there’s also a very slick website that will let users upload and compare their data. This complete user experience gives TestLogger a very professional feel, and we can’t wait to see where [Jussi] takes it from here.

With powerful microcontrollers available for a song, we expect this kind of detailed data collection is only going to become more common.

High Performance Stereo Computer Vision For The Raspberry Pi

August 3, 2019 by Pat Whetman 30 Comments

Up until now, running any kind of computer vision system on the Raspberry Pi has been rather underwhelming, even with the addition of products such as the Movidius Neural Compute Stick. Looking to improve on the performance situation while still enjoying the benefits of the Raspberry Pi community, [Brandon] and his team have been working on Luxonis DepthAI. The project uses a carrier board to mate a Myriad X VPU and a suite of cameras to the Raspberry Pi Compute Module, and the performance gains so far have been very promising.

So how does it work? Twin grayscale cameras allow the system to perceive depth, or distance, which is used to produce a “heat map”; ideal for tasks such as obstacle avoidance. At the same time, the high-resolution color camera can be used for object detection and tracking. According to [Brandon], bypassing the Pi’s CPU and sending all processed data via USB gives a roughly 5x performance boost, enabling the full potential of the main Intel Myriad X chip to be unleashed.

For detecting standard objects like people or faces, it will be fairly easy to get up and running with software such as OpenVino, which is already quite mature on the Raspberry Pi. We’re curious about how the system will handle custom models, but no doubt [Brandon’s] team will help improve this situation for the future.

The project is very much in an active state of development, which is exactly what we’d expect for an entry into the 2019 Hackaday Prize. Right now the cameras aren’t necessarily ideal, for example the depth sensors are a bit too close together to be very effective, but the team is still fine tuning their hardware selection. Ultimately the goal is to make a device that helps bikers avoid dangerous collisions, and we’ve very interested to watch the project evolve.

The video after the break shows the stereoscopic heat map in action. The hand is displayed as a warm yellow as it’s relatively close compared to the blue background. We’ve covered the combination Raspberry Pi and the Movidius USB stick in the past, but the stereo vision performance improvements Luxonis DepthAI really takes it to another level.

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An Exoskeleton Arm For A Hacker On A Budget

August 2, 2019 by Jenny List 4 Comments

Whether it is motivated by a dream of superhuman strength courtesy of a mech suit or of mobility for those with impaired muscle function, the powered exoskeleton exerts a curious fascination among engineers. The idea of a machine-augmented human body achieving great things is thwarted though by the difficulty of the task, actuators and power sources small enough to be worn comfortably represent a significant challenge that is not easily overcome. It’s a subject that has captivated [Kristjan Berce] since at a young age seeing his grandmother struggling with lifting, and he presents a working powered exoskeleton arm as a proof of his ideas.

It’s a wonderful exercise in low-tech construction with hand tools and a drill press on pieces of aluminium and wood. Motive power comes from an automotive windscreen wiper motor, and electrical power comes from a hefty LiPo attached to the device’s harness. There is a feedback potentiometer incorporated into the elbow joint, and an Arduino oversees the operation under the direction of a pair of glove-mounted buttons. It’s certainly impressive to see it in the video below lifting a bicycle, though we wonder how its weight might affect someone with less muscle function than average.

Projects like this one are very good to see, because there’s a chance that somebody out there may be helped by building one of these. However there is always a note of caution to be struck, as the best solutions come from those who need them and not those who merely think they have the solution. We have written about the Engineer Saviour Trap here in years past.

This isn’t the first prosthetic arm we’ve seen though, we covered a hackerspace in England printing one for a local youngster.

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CPAP Monitor Alerts Wearer To Malfunctions

August 1, 2019 by Lewin Day 29 Comments

Continuous Positive Airway Pressure machines are a common treatment tool for sleep apnea and other respiratory issues. A common problem with their use is that the mask becomes dislodged during sleep, and thus fails to provide airway pressure to the patient. [Bin Sun] decided to take a stab at solving this problem.

The project consists of an Arduino fitted with a MPXV7002DP pressure sensor. The sensor is used to monitor the pressure in the CPAP pipes. If the pressure varies regularly, it is likely the system is working. If however, the pressure remains at a roughly constant level, that suggests the mask is no longer properly fitted to the wearer, or that there is another problem. In this event, the device sounds a buzzer to wake the wearer, alerting them to check the equipment.

It’s a simple solution to the problem, and something we’re surprised isn’t built into most CPAP machines from the factory. It’s important to be careful before modifying any medical equipment, though we see plenty of hackers taking the plunge to innovate in this area.

Open Source Smart Display Takes The Long Way Around

July 31, 2019 by Tom Nardi 18 Comments

Thanks to the relatively low cost of the Raspberry Pi and high resolution LCD screens, “smart displays” have become a favorite project of those looking to clear out their parts bins. Just hook the Pi up to the screen, setup some software, and you’ve got yourself a digital bulletin board for your home that can show your schedule, the weather, etc. Build it into a mirror, and you’ve got yourself at least double Internet points.

But when [John Basista] started planning his own smart display, he decided to take the path less traveled. He’s entered the resulting open source project into the 2019 Hackaday Prize, and we’re very excited to see where it goes from here. Even in these early days he’s already made some great strides, with nary a Raspberry Pi in sight.

[John] has nothing against using the Raspberry Pi for these smart displays, and indeed, it has a number of traits which make it particularly well suited to the task. But the problem for him was that it only supported HDMI, and he had his heart set on using an Embedded DisplayPort (eDP) screen. Namely the Innolux N173HCE-E31, a 17.3 inch IPS LCD designed for laptops.

He tried to find a Linux or Android compatible SBC that featured eDP, but found it to be a challenge. There were some x86 options, but didn’t want to go down that road. Eventually he settled on the Dragonboard 410c, which features a quad-core Qualcomm APQ8016E CPU running at 1.2 GHz and 1GB of RAM. This board didn’t have eDP either, but it did have Display Serial Interface (DSI), which he could convert to eDP with the Texas Instruments SN65DSI86 IC.

From there, he started developing a PCB which would hold the Dragonboard 410c and the SN65DSI86. The board also breaks out I2C and UART so he can connect it to various other sensors and gadgetry down the road, and includes all the necessary power regulation to drive everything. The whole thing fits in the palm of your hand, and judging by the renders [John] has put together, should nestle nicely into the back of the 3D printed enclosure when everything is finished.

There’s still quite a bit left to do on this project, but [John] has plenty of time to tie up the loose ends. Currently there’s little information about the software side of things, but as you can see in the video after the break, it’s now running Android which should make things relatively easy.

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