Developed in the very late 60s and through the 70s, the PDP-11 series of minicomputers was quite possibly the single most important computer ever created. The first widely distributed versions of Unix and C were developed on the PDP-11, and it’s hardware influence can be found in everything from the Motorola 68000 to the MSP430.
When [Dave Cheney] saw the recent 8086 simulator written in 4kB of C code, he realized simulating entire computer systems doesn’t actually require a whole lot of resources outside a big chunk of memory. Armed with an Arduino Mega clone, he set out on one of the coolest projects we’ve seen in a while: simulating a PDP-11 on an AVR.
[Dave] used an ATMega2560-powered Arduino Mega clone with an Ethernet module for the hardware of this build. Attached to it is a shield filled up with a pair of RAM chips that expand relatively limited amount of RAM on the ‘Mega.
So far, [Dave] has his simulated system booting Unix V6 off an SD card. For PDP-11 storage, he’s also simulating an RK05 disk drive, a massive 14 inch platter containing 2.5 Megabytes of data. Compared to the original PDP-11/40, [Dave] estimates his machine is about 10 times slower. Still, an original 11/40 system fills multiple server racks, and the most common installations consume several kilowatts of power. The Arduino Mega can fit in a pocket and can be powered over USB.
Future developments for this system include improving the accuracy of the simulator, running more advanced operating systems and the DEC diagnostic programs, and possibly speeding up the simulation. We’d suggest adding some switches and blinkenlights on an additional shield, but that’s just us.
All the code can be found on [Dave]’s git, with a description of his SPI RAM shield coming shortly.
[Jack], a mechanical engineer, loom builder, and avid sailor wanted an autopilot system for his 1983 Robert Perry Nordic 40 sailboat with more modern capabilities than the one it came with. He knew a PC-based solution would work, but it was a bit out of reach. Once his son showed him an Arduino, though, he was on his way. He sallied forth and built this Arduino-based autopilot system for his sloop, the Wile E. Coyote.
He’s using two Arduino Megas. One is solely for the GPS, and the other controls everything else. [Jack]’s autopilot has three modes. In the one he calls knob steering, a potentiometer drives the existing hydraulic pump, which he controls with a Polulu Qik serial DC motor controller. In compass steering mode, a Pololu IMU locks in the heading to steer (HTS). GPS mode uses a predetermined waypoint, and sets the course to steer (CTS) to the same bearing as the waypoint.
[Jack]’s system also uses cross track error (XTE) correction to calculate a new HTS when necessary. He has fantastic documentation and several Fritzing and Arduino files available on Dropbox.
Autopilot sailboat rigs must be all the rage right now. We just saw a different one back in November.
Continue reading “Ride, Captain, Ride Aboard Your Arduino-Controlled Autopiloted Sailboat”
[Hubert] sent us a tip about a friend’s project to rescue a laundromat from its failing electronics. We’re not entirely sure what went wrong with the old control center, but considering a replacement would have cost nearly 25,000 EUR, we think [Stefan] found the perfect solution: he gave it an Arduino and Android overhaul (translated).
Although [Stefan] explains that the boards were defective, perhaps one of our German readers can help us out with a more specific translation. More clear, however, are the steps taken to upgrade the system. The situation at the laundromat was a bit of an emergency: there was no way for customers to pay for use of the machines. As a result, [Stefan] had free reign to overhaul things as he saw fit. He decided to remove the complex button setup in favor of a touchscreen Android tablet, which provided users with a simple interface to make selections. The tablet serves only as an input device. The heavy lifting is handled by an Arduino Mega 2560, which hooks up to what remains of the original system and controls the 27 machines in the laundromat.
[Stefan] admits that he isn’t a particular fan of the Arduino, but that for the price, it’s a tough solution to beat. He’s not the only one overhauling with Arduinos. Check out some other examples of upgraded machines, like the Arduino-enhanced PopCARD vending machine.
UPDATE: [Andreas] sent in a better translation of the project page which we’ve included below. He worries his written English isn’t the best, but we think it is a lot easier to understand than the machine translation. Thank you for you work [Andreas!]
Continue reading “Running a Laundromat with an Arduino”
People have been converting their old Power Macs and Mac G5s into fish tanks for a few years now, but [Hayden’s] Internet-enabled tank is probably the most awesome ever crammed into an aquarium along with the water and the fish—and we’ve seen some fascinating builds this summer. After gutting the G5 and covering the basic acrylic work, [Hayden] started piling on the electronics: a webcam, timed LED lighting, an LCD for status readouts, filter and bubble control via a servo, an ultrasonic sensor to measure water levels, thermometer, scrolling matrix display, an automatic feeding mechanism, and more. He even snuck in the G5’s old mainboard solely for a cool backdrop.
The build uses both a Raspberry Pi and an Arduino Mega, which sit underneath the tank at the base. The Pi provides a web interface written in PHP and jQuery, which presents you with the tank’s status and allows changes to some settings. Nearly every component received some form of modification. [Hayden] stripped the webcam of its case and replaced the enclosure with a piece of acrylic and a mountain of silicone, making it both waterproof and slim enough to fit in the appropriate spot. Though he decided to stick with an Amazon-bought Eheim fish feeder, he disabled the unit’s autofeed timer and tapped in to the manual “feed” button to integrate it into his own system.
It’d take half of the front page to explain the rest of this thing. We’ve decided to let the aquarium tell you the rest of its features in the video below. Yeah…it can talk.
Continue reading “Automated Aquarium is Kitchen-Sinky”
This edition of Fail of the Week is nothing short of remarkable, and your help could really get the failed project back on track. [Snipor Bob] wanted to replace all of the dashboard readouts on his Mustang and got the idea of making the hacked hardware into a Heads-Up Display. What you see above is simply the early hardware proof of concept for tapping into the vehicle’s data system. But there’s also an interesting test rig for getting the windshield glass working as a reflector for the readout.
Continue reading “Fail of the Week: CAN-Bus Attached HUD for Ford Mustang”
[Raffael] had an old Broken Yamaha natural sound receiver lying around. Rather than throw it out, he built himself a slick web radio. He calls it RadioduinoWRT. [Raffael] started by removing all the internals – though he kept the front panel controls. He then added an Arduino Mega to handle the front panel controls, including a 16×2 character LCD module. The Arduino also takes commands via IR remote. An enc28j60 Ethernet module allows the Arduino to communicate with a the brains of the operation, a TL-WR703N mini router.
A micro USB hub expands the single USB port on the WR703, allowing both a USB sound card and a 4 gig USB stick to be mounted. We’d like to add that the TL-WR703 is a must in this application – the amazon link [Rafael] provides brings up the TL-WR702 as a top link. Only the TL-WR703 has a USB host connection.
The real magic is in [Raffael’s] software setup. The WR703 is running OpenWRT. He added modules for the USB sound card, as well as expanding the file system onto the USB stick. Once that was complete [Raffael] added Music Player Daemon (MPD) and MPC, a console app to drive MPD. Lighttpd, a light web server provides an interface for the Arduino as well as a web front end to the entire radio.All this allows [Raffael] to control his radio in several ways. He can log in via any web browser on his network. He can use the front panel controls. He can use an IR remote. Since he is running MPD, any client (there are literally hundreds out there) will also drive the radio.
While a low-end USB sound card in a home stereo application does make our inner audiophile cringe a bit, the quality does seem to be pretty good. [Rafael’s] design would make it simple to swap out a higher quality USB sound card if the need arises.
Continue reading “Classic 80’s Stereo Receiver Enjoys a Second Life as RadioduinoWRT”
[Edward] wanted a different way to modulate notes on his MIDI controller, so he decided to go touchless. Inspired by the pressure-sensing modulation on his Edirol keyboard, [Edward] aligned eight sensors into a row of playable notes and used infrared to sense the distance of a player’s hand from the keys. He also included some function buttons to cycle through 10 octaves and RGB LEDs beneath the table that perform alongside the music.
He chose SHARP GP2D120 sensors (direct link to datasheet) for their low threshold, which allowed the board to detect distance close to the sensor. Each is mounted onto a sheet of frosted acrylic along with its own “hold note” button and an LED to indicate the key is playing. The lower panel houses an Arduino Mega that drives the system along with an RGB LED strip and its driver board. [Edward] used Maxuino and OSC-Route to interface the Mega to a Max/MSP patch which runs the show.
Learn more about the FlightDeck’s features in a video demonstration of the controller and the software after the break, then check out some other MIDI hacks like this organ pedal or the Arduino-driven MIDI sequencer.
Continue reading “FlightDeck: A “Touchless” MIDI Controller”