Nomograms: Complex Analog Calculators Simple for Everyone

In the late 1800s, a railway engineer named Philbert Maurice d’Ocagne was part of a group of men faced with the task of expanding the French rail system. Before a single rail could be laid, the intended path had to be laid out and the terrain made level. This type of engineering involves a lot of cut and fill calculations, which determine where dirt must be added or removed. The goal of earthwork is to create a gentle grade and to minimize the work needed to create embankments.

In the course of the project, d’Ocagne came up with an elegant, reusable solution to quickly  solve these critical calculations. Most impressively, he did it with little more than a pen, some paper, and a straightedge. By developing and using a method which he called nomography, d’Ocagne was able to perform all the necessary calculations that made the gentle curves and slopes of the French railway possible.

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Quadrotor Control Systems And Kerbal Harriers

Kerbal Space Program, the game that teaches engineers at JPL and SpaceX the basics of rocket design and orbital mechanics, recently had a giant update. There are now science contracts that require you to fly Kerbals all over their tiny globe, collect data, and transmit it back to the Kerbal Space Center. As would be expected, this is a grind for XP, and the contracts sometimes don’t make sense – you need to collect data from cliff faces and mountain tops. Landing a Kerbal jet at these places is hard.

[Matt Thiffault] wanted to do these science contracts more efficiently. The best way to get to a remote location without a landing strip would be a helicopter, but a harrier jump jet would do just as well. This isn’t supported in the stock game, so [Matt] wrote a complete control system for four engines to control a hovering Kerbal jet.

[Matt]’s work is built on kOS, a scriptable autopilot mod for Kerbal that was originally intended to be something like the Apollo Guidance Computer. People have been using it to make computerized skycranes and automated rendezvous and docking programs, but these are actually relatively simple examples; there’s far more math involved in flying a quadcopter than there is getting into orbit.

To build his automated hovering harrier, [Matt] needed an aircraft. His Kerrier has parts from the Kerbal Aircraft Expansion, B9, and Infernal Robotics mods for KSP, but this is only half the problem. Anyone can put four tilt jets on an airplane, and it takes a real wizard to force a control system to hover. Hover control of the Kerbal harrier is accomplished with a complete control system for a four-engined aircraft, with proper PID control loops and code updating at 20Hz.

With kOS, the proper plane, and the right software running on this emulated guidance computer, [Matt] is able to park his plane in mid-air, have a Kerbal descend the ladder, perform some science, and return to base. It’s an impressive amount of work for a video game. A good thing, too: [Matt] is looking to get into controls engineering professionally. Whether this will go on his resume is another question entirely.

Hacklet 39: The Kerbal Way Of Doing Things

Kerbal Space Program is a space flight simulator based on an extremely stupid race of green space frogs that have decided to dedicate all their resources towards the exploration of space. It is a great game, a better space simulator than just about anything except for Orbiter, and the game is extremely moddable. For this edition of the Hacklet, we’re going to be taking a look at some of the mods for KSP you can find over on

1271491420181365398Like most hardware builds for Kerbal Space Program, [lawnmowerlatte] is using a few user-made plugins for KAPCOM, a hardware controller and display for KSP. The Telemachus plugin is used to pull data from the game and display that data on a few screens [lawnmower] had sitting around.

There are a few very cool features planned for this build including seven-segment displays, a throttle handle, and neat enclosure.

IMG_20140419_013717[Gabriel] is working on a similar build for KSP. Like the KAPCOM, this one uses the Telemachus plugin, but this one adds three eight-digit, SPI-controlled, seven-segment displays, relegendable buttons, and a Kerbal-insipired frame made out of Meccano.

[Lukas]’ KSP Control Panel is another complicated control system that breaks immersion slightly less than a keyboard. He’s using a Raspberry Pi to talk to the Telemachus server to control every aspect of the craft. From staging to opening up the solar panels, it’s all right there in [Lukas]’ control panel.

You may have noticed a theme with these builds; all of them use the Telemachus plugin for KSP. Even though it’s fairly simple to create plugins for Unity, there really aren’t that many KSP plugins build for these immersive control panels and space flight simulators. Or rather, Telemachus is ‘good enough’. We’d like to see a fully controllable KSP command pod model, just like those guys with 737 flight simulators in their garage. If you have any idea how that could happen, leave a note in the comments.

Rocket Controls Fit for a Kerbal

Kerbal Space Program is a space simulation game. You design spacecraft for a fictional race called Kerbals, then blast those brave Kerbals into space. Sometimes they don’t make it home.

If controlling spacecraft with your WASD keys isn’t immersive enough for you, [marzubus] has created a fully featured KSP control console. It sports a joystick, multiple displays, and an array of buttons and switches for all your flight control needs. The console was built using a modular approach, so different controls can be swapped in and out as needed.

Under the hood, three Arduinos provide the interface between the game and the controls. One Arduino Mega runs HoodLoader2 to provide joystick data over HID. A second Mega uses KSPSerialIO to communicate with the game over a standard COM port interface. Finally, a Due interfaces with the displays, which provide information on the current status of your spacecraft.

All of the parts are housed in an off the shelf enclosure, which has a certain Apollo Mission Control feel to it. All [marzubus] needs now is a white vest with a Kerbal badge on it.

Custom Controllers For Kerbal Space Program

kerbalKerbal Space Program is already a runaway indie video game hit, and if you ask some people, they’ll tell you it is the way to learn all about orbital dynamics, how spaceships actually fly, the challenges of getting to the mün. The controls in KSP are primarily keyboard and mouse, something that really breaks the immersion for a space flight simulator. We’ve seen a few before, but now custom controllers well suited for a Kerbal command pod can be made at home, with all the blinkey LEDs, gauges, and buttons you could want.

[Freshmeat] over on the KSP forums began his space adventures with a keyboard but found the fine control lacking. An old Logitech Dual Shock controller offered better control, but this gamepad doesn’t come with a throttle, and USB throttles for flight sims are expensive. He found a neat plugin for KSP made for interfacing an Arduino, and with a few modifications, turned his controller into a control panel, complete with sliders, pots, gauges, and all the other goodies a proper command pod should have.

[Freshmeat]’s work is not the only custom Kerbal controller. There’s a whole thread of them, with implementations that would look great in everything from a modern spaceplane to kerbalkind’s first steps into the milky abyss of space. There’s even one over on the Hackaday projects site, ready to fly Bill, Bob, and Jeb to the mün or a fiery explosion. Either one works.

Thanks [drago] for the tip.

Hackaday Links: January 26, 2014


The automotive industry is rolling more and more tech into their offerings. This is great for us because replacement or salvaged parts are great for projects. Here’s one component to look for. [MikesElectricStuff] tears apart the thermal imaging camera form an Audi. [via Hacked Gadgets]

Give your valentine an analog love note on the big day. [Tom’s] LED heart chaser design does it without any coding. It’s a 555 timer with CD4017 decade counter. The nice thing about the setup is a trimpot adjusts the chaser speed.

[Jan] is overclocking his Arduino to 32 MHz. For us that’s kind of an “eh” sort of thing. But his statement that you need to use a clock generator because the chip won’t work with an oscillator at that frequency raised an eyebrow. We saw an AVR chip running from a 32MHz crystal oscillator in the RetroWiz project from yesterday. So do we have it wrong or does [Jan]? Share your opinion in the comments.

Download a copy of the Apple II DOS source code… legally. Yay for releasing old code into the wild! The Computer History Museum has the DOS source code and a bunch of interesting history about it. [via Dangerous Prototypes]

While we were prowling around DP for the last link we came across [Ian’s] post on a new version of Bus Pirate cables. We’ve got the old rainbow cables which are pretty convenient. But if you’ve used them you’ll agree, hunting for the correct color for each connection isn’t anywhere near a fool-proof method. The new cable uses shrink tube printed with probe labels. They sound like a huge pain to manufacture. But this makes connections a lot easier. In our experience, when it doesn’t work its always a hardware problem! Hopefully this will mean fewer botched connections.

Make your tiny LiPo cells last longer. Not capacity wise, but physically. The delicate connections to the monitor PCB break easily, and the plug is really hard to connect and disconnect. [Sean] shows how he uses electrical tape for strain relief, and a bit of filing to loosen up the connector.

KerbalEdu: Kerbal Space Program for education. That’s right, you can play Kerbal as part of school now. Some may shake their heads at this, but school should be fun. And done right, we think gaming is a perfect way to educate. These initiatives must be the precursor to A Young Lady’s Illustrated Primer method of education. Right?

Turning Kerbal Space Program into a proper space simulator


Kerbal Space Program – the game of freakin’ space Lego and incompetent little green men – has seen a lot of popularity since it was on the Steam Summer sale. Now, in a bid to out do the flight sim aficionados who build 737 cockpits in their garage, a few enterprising Kerbalnauts are building custom controllers for this wonderful introduction to [Tsiolkovsky], [Goddard], and [Evel Kinevel].

[vladoportos] thought KSP could use custom gaming controllers to provide switches for staging, attitude hold, and reaction control system commands. In the game, these are toggled by keyboard input, but this unfortunately destroys the immersion of being a rocket-powered angel of death for your Kerbal volunteers. He rigged up an Arduino Leonardo to send USB HID commands to his computer whenever he pressed one of the buttons connected to his breadboard controller. It’s a work in progress, but [vladoportos] has some big plans that include a physical nav ball to show his ship’s orientation in space.

USB input is one thing, but that’s only half the problem. If you want to build a real Kerbal ship simulator, you’ll need to get data out of the game, and into your glass or analog displays. [voneiden] over on the KSP subreddit has the solution for you. He’s been working on a ‘mission control’ app that runs in Python, connects to a Kerbal Space Program plugin over TCP, and displays flight information such as speed, altitude, longitude, latitude, apoapsis, and periapsis.  The code is up on his git, ready for some individual to bring this over to a Raspi and a character LCD display.