A Tweeting Vending Machine

[Sigurd] manage to obtain an old vending machine from his dorm. The only problem was that the micocontroller on the main board was broken. He and his friend decided they could most likely get the machine back into working order, but they also knew they could probably give it a few upgrades.

This system uses two Arduino Pro Minis and an Electric Imp to cram in all of the new features. One Arduino is connected to the machine’s original main board. The Arduino interfaces with some of the shift registers, relays, and voltage regulators. This microcontroller also lights up the buttons on the machine as long as that particular beverage is not empty. It controls the seven segment LED display, as well as reading the coin validator.

The team had to reverse engineer the original coin validator in order to figure out how the machine detected and counted the coins. Once they figured out how to read the state of the coins, they also built a custom driver board to drive the solenoids.

A second Arduino is used to read NFC and RFID cards using a Mifare RC522 reader. The system uses its own credit system, so a user can be issued a card with a certain amount of pre-paid credit. It will then deduct credit appropriately once a beverage is vended. The two Arduinos communicate via Serial.

The team also wanted this machine to have the ability to communicate with the outside world. In this case, that meant sending cheeky tweets. They originally used a Raspberry Pi for this, but found that the SD card kept getting corrupted. They eventually switched to an Electric Imp, which worked well. The Arduino sends a status update to the Imp every minute. If the status changes, for example if a beverage was dispensed, then the Imp will send a tweet to let the world know. It will also send a tweet to the maintenance person if there is a jam or if a particular slot becomes empty. Continue reading “A Tweeting Vending Machine”

Use Ruby to Make Any Window A Blinken Window

[Akhil Stanislavose] wanted to spice up his window decorations for the holidays. Inspired by blinkenlights, he decided to make his front window interactive. The Blinken Window is a grid of 6 x 10 programmable LEDs running on a Raspberry Pi. Since a RasPi doesn’t have enough GPIO pins for 60 LEDs, [Akhil] built an expander board using 8 daisy chained standard CD4094 (74HC595 could also be used) shift registers to accommodate them.

[Akhil] designed a PCB to replace the expander board for future use. It is modular in nature so that many of them can be connected together to provide as many outputs as one needs, allowing any size window to become a Blinken Window. The PCBs are still being fabricated, but the Eagle files are available for download (zip file). Ruby was used to implement the API. You can find the project files on GitHub, which also features a simulator that you can run on your computer to see how an animation or game will end up looking on the window. In the demo video, [Akhil] demonstrates how you can use the Blinken Window to play a version of Pong using your smartphone as the controller. [Akhil] has also provided a few basic animation examples that can be expanded upon. We’d enjoy seeing an implementation of Tetris. There’s so many fun ways to turn regular windows into dynamic displays, we’re starting to look scornfully at our own lazy, air leaking windows.

See the Blinken Window in action after the break.

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Automated Mushroom Cultivation

Lots of people have developed their own systems for automating the growth of plants. Keeping the environment under tight control leads to better yield, and computers are better than humans at remembering to water the plants regularly. [Kyle] is into growing mushrooms (the legal, edible type) and automating things. This led to his system for automated mushroom cultivation.

We’ve seen an automated system for growing fungi before, but [Kyle]’s project is a bit bigger. He’s built a sealed room for growing mushrooms. The room is sealed with a plastic sheet, using magnetic strips to create a doorway. Within the room, a heater, humidifier, and circulation fan control the environment. Temperature, humidity, and dew point in the chamber are constantly monitored and adjusted as necessary.

The entire system is controlled with a Raspberry Pi and custom software, which is available on Github. GNUPlot is used to generate graphs, which are accessible through a web server. The web interface also allows the parameters of the chamber to be tweaked remotely. Based on the settings, the Raspberry Pi controls a set of relays to keep the chamber in an ideal state.

Photonic Reset of the Raspberry Pi 2

For the past month, the Raspberry Pi 2 has only been available to the Raspi Foundation, and for about 2 weeks, select members of the media who have worn the Raspi 2 on a necklace like [Flavor Flav] wears a clock. That’s not many people with real, working hardware and when a product is released, the great unwashed masses will find some really, really weird bugs. The first one to crop up is a light-sensitive reset of the Raspberry Pi 2.

[PeterO] on the Raspberry Pi forums took a few pictures – with flash – of a running Raspberry Pi 2. It took a little bit of deduction to realize that a camera flash will either reset or turn the Raspi 2 off. Yes, this is weird, and experiments are ongoing.

A short video from [Mike Redrobe] confirms the finding and a reddit thread offers an explanation. U16, a small chip located in the power supply part of the Raspi 2, is sensitive to light. Putting enough photons will cause the Pi to shut down or restart.

There’s still some research to be done, however, I can confirm a cheap green laser pointer will reset a Raspberry Pi 2 when the beam is directed at the U16 chip. This is the chip that is responsible, and this is not an EMP issue. This is a photon/light issue with the U16 chip. The solution to this bug is to either keep it in a case, or put a tiny amount of electrical tape over the chip.

Thanks [Arko] for staying up until an ungodly hour and sending this to me.

A Raspberry Pi SID Player

Of all the vintage chiptune machines out there, the Commodore 64 is the most famous. Even 30 years later, there are still massive gatherings dedicated to eeking out the last cycle of processing power and graphics capability from the CPU and the infamous synth-on-a-chip, the SID. [Bob] wanted to build a SID jukebox. A C64 is capable of the job, but if you want to have every SID composition on an SD card and connect that to a network, a Raspberry Pi is the way to go.

The SID chip, in its 6581 or 8580 versions, is controlled directly by poking registers on the chip through the address and data busses. This means a lot of pins, too many for the original Raspi expansion header. That’s not a problem that can’t be solved with a few shift registers, though. The rest of the circuit is an LM386 audio amplifier, an LCD that displays the current song, and a can crystal oscillator for the SID.

Right now everything is wired up on a breadboard, but making this a Raspberry Pi hat would be a rather simple proposition. It’s only a matter of finding a SID with working filters, and if you can manage that, it’s a pretty easy build to replicate. Video below.

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Hacklet 33 – Minecraft Projects

Minecraft hit the PC gaming scene as an alpha release on May 17, 2009. Something about the open world, the crafting system, and the various modes of gameplay made it an instant hit. Since then Minecraft become one of the best selling video games of all time, inspiring thousands of hacks, mods, and projects. This week’s Hacklet highlights some of the best Minecraft projects on Hackaday.io!

clawWe start with [Toulon] and his MineCraft Sidecar Keypad. The Mystify Claw was originally designed as an alternative input device for First Person Shooter (FPS) games. It may look like a mouse, but the claw has no balls or lasers. It provides a 10 button “cradle” for the left hand. Some folks liked the claw, but for many it quickly became a dust collector. [Toulon] resurrected this old input device as an awesome Minecraft controller. He started by yanking all the old electronics, replacing the claw’s brain with the Teensy 2.0, a favorite of keyboard hackers everywhere. New buttons and a slew of new Teensy code made things perfect for mining.

rappiNext up is [Thomas] and his Raspberry Minecraft Server. The Raspberry Pi has long been a hacking platform for Minecraft. The official Raspberry Pi edition of Minecraft is easy to get running, and great for hours of fun. You can also run a Minecraft server on the Pi, which is exactly what [Thomas] is doing. He’s set his Raspberry Pi up with a WiFi dongle and a battery pack. With a bit of configuration, this allows the Pi to become the center of a wireless Lan party. On batteries, the Pi will run for about five hours of continuous gaming. Details for [Thomas’] project are a bit light right now, but that’s only because he just literally started documenting and uploading his project as we’re going to press. Give him a few days and he’ll have everything filled in!

gppk[GPPK] brings a bit of Minecraft into the real world with Full Size Wireless Redstone Lamp. Inspired by smaller models of the Minecraft redstone lamp, [GPPK] decided to build a life-sized version. “Life-sized” in this case is about 1 cubic meter. That’s a BIG lamp! [GPPK] designed the shell of the lamp in Sketchup, and cut the sides out using a gantry style CNC machine. The structure will be held together with 3D printed connectors, while a Raspberry Pi will provide the brains. Turning the lamp on will be as simple as turning on a switch in-game in Minecraft. [GPPK] has been a bit slow lately with updates on the project. If you know [GPPK] let ‘em know that we’re anxiously awaiting some info!

pipyFinally, we have [Simon] and Raspberry Pi Python Controller. One of the best ways to get kids hooked on hacking and electronics is to show them how simple circuits can lead to big changes. What better way to do that than wiring up a simple push button controller for Minecraft? [Simon] used an Arduino paired to a Raspberry Pi with a serial over USB connection. Buttons wired to the Arduino are sent through the serial link to the Pi, where a python script fires off actions based on the serial data. [Simon] has tested his script with Mincraft Pi Edition, and is happy to report back that it works great.

Do you know what’s missing from this Hacklet? Your Minecraft project! It’s not too late though – upload your info to Hackaday.io, and we might just add it to our brand new Minecraft Projects List!

Well, it’s just about quitting time here in the Hackaday Mine. As long as the creepers don’t get us, we’ll be back next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Benchmarking The Raspberry Pi 2

The Raspberry Pi has only been available for a few days, but already those boards are heading through the post office and onto workbenches around the world. From the initial impressions, we already know this quad-core ARMv7 system boots in about half the time, but other than that, there aren’t many real benchmarks that compare the new Raspberry Pi 2 to the older Raspi 1 or other similar tiny Linux dev boards. This is the post that fixes that.

A word of warning, though: these are benchmarks, and benchmarks aren’t real-world use cases. However, we can glean a little bit of information about the true performance of the Raspberry Pi 2 with a few simple tools.

For these tests, I’ve used Roy Longbottom’s Raspberry Pi benchmarking tools, nbench, and a few custom tools to determine how fast both hardware versions of the Raspberry are in real-world use cases.

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