If you’ve seen color sensors such as the TCS34725,  you may have considered them for projects that can pick out one colored object over another. On the other hand, if you were to take one of these sensors, mount them to an Arduino-driven plotter, and then take readings in an X/Y plane, you’d have all the elements needed for a simple single-pixel scanner.

In the video seen below, Kerry D. Wong does just this using his hacked HP 7044A plotter to scan a picture, recording RGB color values in a 128 x 128 grid. As the device scans, the Arduino Due used for control passes these values to a computer, which assembles them together into a low-resolution image.

You can find more details on the project, including its code, in Wong’s blog post here.

When you think of image processing, you probably don’t think of the Arduino. [Jan Gromes] did, though. Using a camera and an Arduino Mega, [Jan] was able to decode input from an Arduino-connected camera into raw image data. We aren’t sure about [Jan’s] use case, but we can think of lots of reasons you might want to know what is hiding inside a compressed JPEG from the camera.

The Mega is key, because–as you might expect–you need plenty of memory to deal with photos. There is also an SD card for auxiliary storage. The camera code is straightforward and saves the image to the SD card. The interesting part is the decoding.

The use case mentioned in the post is sending image data across a potentially lossy communication channel. Because JPEG is compressed in a lossy way, losing some part of a JPEG will likely render it useless. But sending raw image data means that lost or wrong data will just cause visual artifacts (think snow on an old TV screen) and your brain is pretty good at interpreting lossy images like that.

Just to test that theory, we took one of [Joe Kim’s] illustrations, saved it as a JPEG and corrupted just a few bytes in a single spot in it. You can see the before (left) and after (right) picture below. You can make it out, but the effect of just a few bytes in one spot is far-reaching, as you can see.

The code uses a library that returns 16-bit RGB images. The library was meant for displaying images on a screen, but then again it doesn’t really know what you are doing with the results. It isn’t hard to imagine using the data to detect a specific color, find edges in the image, detect motion, and other simple tasks.

Sending the uncompressed image data might be good for error resilience, but it isn’t good for impatient people. At 115,200 baud, [Jan] says it takes about a minute to move a raw picture from the Arduino to a PC.

We’ve seen the Arduino handle a single pixel at a time. Even in color. The Arduino might not be your first choice for an image processing platform, but clearly, you can do some things with it.

This LED heads-up display is a simple modification for your car, but it makes your car look very futuristic.

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The post Hack Your Car into the Future with an LED Heads-Up Display appeared first on Make: DIY Projects and Ideas for Makers.

This LED heads-up display is a simple modification for your car, but it makes your car look very futuristic.

Read more on MAKE

The post Hack Your Car into the Future with an LED Heads-Up Display appeared first on Make: DIY Projects and Ideas for Makers.

If you’ve done 3D printing, you’ve probably at least heard of Tinkercad. This popular CAD package runs in your browser and was rescued from oblivion by Autodesk a few years ago. [Chuck] recently did a video about a new Tinkercad feature: building and simulating virtual Arduino circuits. You can watch it below.

There are a variety of components you can add to your design. You’ll find an integrated code editor and a debugger. You can even get to the serial monitor, all in your browser with no actual Arduino hardware. You can also build simple circuits that don’t use an Arduino, although the component selection is somewhat limited.

This could be great for teaching Arduino in classrooms or when you want to do some development in a hotel room. The layout is very visual, so if you are accustomed to reading schematics, you may not appreciate the style. In addition, the selection of components is somewhat limited (including only supporting the Arduino UNO, as far as we could tell). So for educational purposes, it is great. For breadboarding your next great Arduino-powered robot, maybe not so much.

If you remember Circuits123 (or circuits.io), this is the same underlying technology. They’ve just integrated it with Tinkercad. However, there doesn’t seem to be any real integration between the two other than they are on the same web page now. Perhaps in the future, they’ll let you drop components on the circuit that also show up in the 3D design (or, at least, with sockets or holders for those components).

However, having a simulated Arduino with a debugger could come in handy even if you don’t care about the circuit simulations. If you really want to do circuit simulation, it is hard to go wrong with LTSpice. If you really want it to be in your browser, there’s always Falstad.

If you are working with OBD2 hardware or software, it’s easy enough to access test data, simply plug into a motor vehicle with an OBD2 socket. If, however, you wish to test OBD2 software under all possible fault conditions likely to be experienced by an engine, you are faced with a problem in that it becomes difficult to simulate all faults on a running engine without breaking it. This led [Fixkick] to create an OBD2 simulator using a secondhand Ford ECU supplied with fake sensor data from an Arduino to persuade it that a real engine was connected.

The write-up is quite a dense block of text to wade through, but if you are new to the world of ECU hacking it offers up some interesting nuggets of information. In it there is described how the crankshaft and camshaft sensors were simulated, as well as the mass airflow sensor, throttle position, and speedometer sensors. Some ECU inputs require a zero-crossing signal, something achieved with the use of small isolating transformers. The result is a boxed up unit containing ECU and Arduino, with potentiometers on its front panel to vary the respective sensor inputs.

We’ve brought you quite a few OBD2 projects over the years, for example, there was this LED tachometer, and a way into GM’s OnStar.

Thanks [darkspr1te] for the tip.

Steven Gioiosa recently signed up for a “Makecourse” class at the University of South Florida, where he was required to build something that featured both an Arduino and a 3D-printed part. As a fan of Portal, and especially the sentry turrets in the game, it was an easy decision to construct one of these devices for himself.

Gioiosa’s turret recreation is based on an Arduino Uno connected to an HC-SR04 ultrasonic sensor, and features motion-activated lasers that move back and forth, along with audio feedback, depending on how far away the human target is. The project also involves a bunch of servos: one to open the arms out, another to pitch them up and down, and two more to move each arm left and right.

You can see Gioiosa’s sentry turret in action below, and find more details on his Instructables write-up here.

In May of 2000, then-President Bill Clinton signed a directive that would improve the accuracy of GPS for anyone. Before this switch was flipped, this ability was only available to the military. What followed was an onslaught of GPS devices most noticeable in everyday navigation systems. The large amount of new devices on the market also drove the price down to the point where almost anyone can build their own GPS tracking device from scratch.

The GPS tracker that [Vadim] created makes use not just of GPS, but of the GSM network as well. He uses a Neoway M590 GSM module for access to the cellular network and a NEO-6 GPS module. The cell network is used to send SMS messages that detail the location of the unit itself. Everything is controlled with an ATmega328P, and a lithium-ion battery and some capacitors round out the fully integrated build.

[Vadim] goes into great detail about how all of the modules operate, and has step-by-step instructions on their use that go beyond what one would typically find in a mundane datasheet. The pairing of the GSM and GPS modules seems to go match up well together, much like we have seen GPS and APRS pair for a similar purpose: tracking weather balloons.

Whether to enhance one’s abilities or to compensate for a loss of strength due to a variety of reasons, the idea of a robotic exoskeleton is an exciting prospect. As seen here, Kristjan Berce, not content to let well-funded labs have all the fun, decided to make his own prototype assistive arm using simple hand tools to manufacture a bracing system over his left arm.

Control for the device, which is called “ExoArm,” is accomplished with an Arduino Uno that powers a windshield wiper motor via a driver board. As set up now, it extends via sensor input, and contracts with the push of a button.

Though it can be seen helping him lift a bicycle at the end of both of his videos, figuring out how to balance any load on the system with his actual muscle’s input is a challenge he’s still working on, but hopes to solve this issue using a strain gauge.

Total cost of ExoArm? $100. You can follow along with Berce’s progress on the project’s log here.

Mechanical typewriters are, for the most part, a thing of the past. Though the tactile feedback of these machines is interesting, as is the ability to directly mark on a piece of paper, they lack the important ability to input instructions into a modern computer. Konstantin Schauwecker, not satisfied with this analog-only output, decided to retrofit a German Olympia Monica typewriter as a unique digital user input device.

To accomplish this, he created a PCB with phototransistors that sense when the linkages for each key are pushed down. The result is a keyboard that functions perfectly well as a manual typewriter, and pushes this data to a computer using an Arduino Leonardo.

I modified a vintage type writer to function as a USB keyboard using an Arduino and 50 phototransistors. The typewriter is a German Olympia Monica that I bought at a local flea market. For this project I created a simple PCB that carries the phototransistors and several multiplexers and decoders. The PCB is connected to the Arduino through a ribbon cable. I used an Arduino Leonardo, which can function as a USB input device.

Check out Schauwecker’s write-up for more info on this clever build.