Friday Hack Chat: Making Programming Easier

There is a long history of graphical programming languages. Some people don’t like to code, and for them, graphical programming languages replace semicolons and brackets with easy-to-understand boxes and wires.

This Friday, we’re going to be talking about graphical programming languages with [Boian Mitov]. He’s a software developer, founder of Mitov Software, and the creator of Visuino, a graphical programming language for the embedded domain. He specialized in video, audio, DSP, DAQ, industrial automation, communications, computer vision, artificial intelligence, as well as parallel and distributed computing. [Boian] is the author of the OpenWire open source technology, the IGDI+ open source library, the VideoLab, SignalLab, AudioLab, PlotLab, InstrumentLab, VisionLab, IntelligenceLab, AnimationLab, LogicLab, CommunicationLab, and ControlLab libraries, OpenWire Studio, Visuino, and author of the “VCL for Visual C++” technology.

For this Hack Chat, we’re going to be talking about ways to make programming microcontrollers easier. The focus of this discussion is Visuino, a graphical programming environment. Visuino allows anyone to program an Arduino, Teensy, or an ESP simply by connecting wires and choosing some logic. Think of it as a step above the programming environment that came with the Lego Mindstorms, Scratch, or whatever else MIT was coming out with in the early ‘aughts.

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.join-hack-chat

Our Hack Chats are live community events on the Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, May 25th.  Here’s a clock counting down the time until the Hack Chat starts.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

State Your Intentions More Clearly With State Machines

To the uninitiated the words ‘State machine’ sound like something scarily big and complex. They aren’t (necessarily) and can be quite useful. In fact, state machines are no physical machines but a model of processes. They link the states a system can be in with allowed transitions. For example a media player when stopped can change to play or open another file. While playing, it can go to pause, stop, reverse, fast forward and so on. A state machine creates a map of all states and how they are connected. It is an abstract tool hat offers a graphical approach to organizing your code before actually programming.

In his video [Chris Guichet] uses a state machine to debounce a switch for a beginner friendly introduction of the concept. He then shows how to turn the hand drawn map to actual code, including a section on debugging state machines.

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Learn Programming From Ants

Humans and insects think on a different scale, but entomologists study the behavior of these little organisms, so they’re not a complete mystery. There isn’t much intelligence in a single ant or a cubic millimeter of gray matter, but when they all start acting together, you get something greater than the sum of the parts. It is easy to fall into the trap of putting all the intelligence or programming into a single box since that’s how we function. Comparatively, itty-bitty brains, like microcontrollers and single-board computers are inexpensive and plentiful. Enter swarm mentality, and new tasks become possible.

[Kevin Hartnett] talks about a paper researching the simple rules which govern army ants who use their bodies as bridges when confronted with a gap in their path. Anyone with a ruler and a map can decide the shortest route between two places, but army ants perform this optimization from the ground, real-time, and with only a few neurons at their disposal. Two simple rules control bridge building behavior, and that might leave some space in the memory banks of some swarm robots.

A simpler example of swarm mentality could be robots which drive forward anytime they sense infrared waves from above. In this way, anyone watching the swarm could observe when an infrared light was present and where it was directed. You could do the same with inexpensive solar-powered toy cars, but we can already see visible light.

We’re not saying ants should be recruited to control robots, but we’re not objecting to the humane treatment of cyborg bugs either. We’ve been looking into swarm robots for a long time.

Thanks for the tip, [JRD].

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Running Programs On Paper

It’s a simple fact that most programs created for the personal computer involve the same methods of interaction, almost regardless of purpose. Word processors, graphics utilities, even games – the vast majority of interaction is performed through a keyboard and mouse. However, sometimes it can be fun to experiment with alternative technologies for users to interact with code – Paper Programs is an exciting way to do just that.

Paper Programs is a combination of a variety of existing technologies to create a way of interacting with code which is highly tangible. The setup consists of a projector, and a webcam which can see the projected area, combined with Javascript programs running in a browser. Programs can be edited in the browser, then printed out with special coloured dots around the page. When the page is placed in the projection area, these dots identify the unique program and are picked up by the webcam, and the server executes the relevant code, projecting back onto the page.

It’s a system that creates a very tactile way of interacting with a program – by moving the page around or placing different pages next to each other, programs can interact in various ways. The system is setup for collaboration as well, allowing users to edit code directly in the browser.

The project reminds us of earlier works on DIY multitouch screens, but with a greater focus on direct engagement with the underlying code. What other unique ways exist to interact with code? Let us know in the comments.

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MicroPython learns a new trick – ISP for AVRs

One of the reasons why the Arduino became so popular was the ability to program it with ease. It meant the end of big parallel programmers that would cost an arm and a leg. The latest installment of CircuitPython from [Lady Ada] and the team over at Adafruit is a library for programming AVR microcontrollers without a dedicated PC.

For the uninitiated, in-system programming or ISP for AVR controllers employ the SPI bus to write the compiled binary to the flash memory of the controller. The discount on the number of pins used itself is a benefit though getting the timings right was a bit tricky in the good old days. Most dedicated ISPs handle this nicely, though they are normally slaves to a host PC where an ‘upload’ button initiates the process.

With CircuitPython (a derivative of MicroPython), programming microcontrollers does not require going through the code-compile-flash cycle. It can be run on a number of processors, however, AVRs are not among them so this neat little library offers the next best thing. Wire-up an Atmega328P or ATmega2560 to a board like the ESP8266 that does run CircuitPython, and you can write firmware on the fly.

There is a complete tutorial on the subject thanks to [Phillip Torrone] and [Lady Ada] which includes some demo files for testing out the functionality. This opens up a lot of possibilities where OTA firmware updates for an AVR co-processor. We expect to see some keychain AVR programmers in the near future taking a hint from the ESP8266 based Two-Factor Authentication featured previously.

Solving Mazes with Graphics Cards

What if we told you that you are likely to have more computers than you think? And we are not talking about things that are computers while not looking like one, like most modern cars or certain lightbulbs. We are talking about the powerful machines hiding in your desktop computer called ‘graphics card’. In the ordinary gaming rig graphics cards that are much more powerful than the machine they’re built into are a common occurrence. In his tutorial [Viktor Chlumský] demonstrates how to harness your GPU’s power to solve a maze.

Software that runs on a GPU is called a shader. In this example a shader is shown that finds the way through a maze. We also get to catch a glimpse at the limitations that make this field of software special: [Viktor]’s solution has to work with only four variables, because all information is stored in the red, green, blue and alpha channels of an image. The alpha channel represents the boundaries of the maze. Red and green channels are used to broadcast waves from the beginning and end points of the maze. Where these two waves meet is the shortest solution, a value which is captured through the blue channel.

Despite having tons of cores and large memory, programming shaders feels a lot like working on microcontrollers. See for yourself in the maze solving walk through below.

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Educational Robot for Under $100

While schools have been using robots to educate students in the art of science and engineering for decades now, not every school or teacher can afford to put one of these robots in the hands of their students. For that reason, it’s important to not only improve the robots themselves, but to help drive the costs down to make them more accessible. The CodiBot does this well, and comes in with a price tag well under $100.

The robot itself comes pre-assembled, and while it might seem like students would miss out on actually building the robot, the goal of the robot is to teach coding skills primarily. Some things do need to be connected though, such as the Arduino and other wires, but from there its easy to program the robot to do any number of tasks such as obstacle avoidance and maze navigation. The robot can be programmed using drag-and-drop block programming (similar to Scratch) but can also be programmed the same way any other Arduino can be.

With such a high feature count and low price tag, this might be the key to getting more students exposed to programming in a more exciting and accessible way than is currently available. Of course, if you have a little bit more cash lying around your school, there are some other options available to you as well.