Raspberry Pis And A Video Triptych

A filmmaker friend of [Thomas] mentioned that she would like to display a triptych at the 2015 Venice Art Walk. This is no ordinary triptych with a frame for three pictures – this is a video triptych, with three displays each showing a different video, and everything running in sync. Sounds like a cool engineering challenge, huh?

The electronics used in the build were three Raspberry Pi 2s and a trio of HDMI displays. Power is provided by a 12V, 10A switching supply with 5V stepdown converters for the Pis. The chassis is a bunch of aluminum bars and U channel encased in an extremely well made arts and crafts style frame. So far, nothing out of the ordinary.

Putting three monitors and three Pis in a frame isn’t the hard part of this build; getting three different displays all showing different videos is. For this, [Thomas] networked the Pis through an Ethernet hub, got the videos to play independently on a RAM disk with omxplayer. One of the Raspberry Pis serves as the master, commanding the slaves to start, stop, and rewind the video on cue. According to [Thomas], it’s a somewhat hacky solution with a bunch of sleep statements at the beginning of the script to allow the boot processes to finish. It’s a beautiful build, though, and if you ever need to command multiple monitors to display the same thing, this is how you do it.

LED Notification Cube is a Good First Project

Two years ago, [Matt] made a move away from his software hacks and into the physical world. He was part of a pilot program to provide mentorship to children as part of the Maker Education Initiative. This program gave him access to 3D printers, CNC machines, and laser cutters within the New York Hall of Science makerspace. [Matt] chose to build an illuminated notification cube for his first physical project. The idea being that smart phones have so many alerts, many of which are unimportant. His project would help him to visualize and categorize each alert to better understand its importance.

The brain of the system is a Raspberry Pi. [Matt] found a Python library that allowed him to directly control an RGB LED strip based on the LPD8806 chip. He wired the data pins directly to the Pi and used an old 5V cell phone charger to power the LEDs. The strip was cut into smaller strands. Each face of the cube would end up with three strands of two LEDs each, or six LEDs per side. [Matt] found a mount for the Pi on Thingiverse and used a 3D printer to bring it into existence. The sides were made of frosted laser cut acrylic. The frosted look helps to diffuse the light from the LEDs.

Over time [Matt] found that the cube wasn’t as useful as he originally thought it would be. He just didn’t have enough alerts to justify the need. He ended up reprogramming the Pi to pull weather information instead, making use of the exact same hardware for another, more useful purpose.

Raspberry Preserve – A BitTorrent Sync client in a Mason Jar

[Matt Reed] used a few off-the-shelf parts and built a Raspberry-Pi based BitTorrent Sync client to help backup files. What makes it stand out is the idea of using a Mason Jar as the enclosure and the nice build finish. Mason Jars have long been used to preserve food. [Matt] wanted to use the Mason Jar to help preserve family memories.

Basically, he just stuffed a Raspberry Pi inside a jar with some LED’s and put BitTorrent Sync on it. He started off with a nice, square piece of wood and mounted the lid on it. Holes were drilled to fix the four LED’s and faux crystal drawer pull knobs. The Pi was connected to power and Ethernet and the LED’s wired up. The software is quite straightforward – just install BitTorrent Sync on the Raspberry Pi. He wrote a Node.js script to constantly check if BitTorrent Sync is transferring any data, and if it is, blink the LED’s so it looks cool. If no data is being transferred, the LED’s just glow solid red. Once it is plugged into power and connected to the internet, any photo or video (or any file for that matter) that is put inside a special folder called “Preserve” on any of his devices, gets sync’ed and copied to the “Raspberry Preserve” – preserved for posterity.

C.H.I.P. is a Linux Trojan Horse for Nine Bucks

I’m sure you’ve already heard about C.H.I.P, the $9 Linux computer. It is certainly sexy to say nine-bucks but there should really be an asterisk next to that number. If you want things like VGA or HDMI you need an adapter board which adds cost (natively the board only supports composite video output). I also have questions about MSRP once the Kickstarter is fulfilled. But what’s on my mind isn’t cost; this is still going to be in the realm of extremely-inexpensive no matter what shakes out. Instead, I’d like to look at this being the delivery device for wider Linux acceptance.


The gist of the hardware is a small board with a SoC boasting a 1GHz clock, half a gig of ram, four gigs of flash, one USB, WiFi and Bluetooth. It also has add-ons that make it a handheld and is being promoted as a gaming console. It’s amazing what you get out of these SoC’s for the cost these days, isn’t it?

For at least a decade people have claimed that this is the year of the Linux desktop. That’s not the right way to think. Adults are brand-loyal and business will stick to things that just work. Trying to convert those two examples is a sisyphean effort. But C.H.I.P. is picking up on a movement that started with Raspberry Pi.

These are entry-level computers and a large portion of the user-base will be kids. I haven’t had a hands-on with this new board, but the marketing certainly makes an effort to show how familiar the GUI will be. This is selling Linux and popular packages like LibreOffice without even tell people they’ll be adopting Linux. If the youngest Raspberry Pi users are maturing into their adolescence with C.H.I.P, what will their early adult years look like? At the least, they will not have an ingrained disposition against Open Source Software (unless experiences with Rasbperry Pi, C.H.I.P., and others is negative). At best they’ll fully embrace FOSS, becoming the next generation of code contributors and concept evangelists. Then every year will be the year of the Linux desktop.

Hacklet 46 – ODROID Projects

It seems you can’t mention the Raspberry Pi these days without someone bringing up the Odroid. Named after the combination of Open and Android, the current Odroid brand covers several boards – the U3, the UX3 with its 2 Ghz Samsung quad-core processor, and the C1, which is directly aimed at our favorite fruit pie computer. With all this popularity, one would expect a few awesome projects based around the Odroid machines, and you’d be right! This week’s Hacklet is all about projects using the Odroid on Hackaday.io!

Robbie jrWe start with [herrkami] and CRONUS. Cronus started life as a Robbie Junior, Radio Shack’s re-branded version of Takara Tomy’s Omnibot Jr.  [herrkami] has upgraded Cronus’ brain with an Odroid U3. Cronus can now reliably respond to voice commands thanks to a little help from Google’s speech recognition engine and the accompanying Python API. Cronus is rather conversational as well, all due to the AIML framework. [herrkami] hopes to cut the cord (or WiFi link) once he gets CMU sphinx up and running. Some of [herrkami’s] best work is in his cardboard templates to create a mechanism for turning Cronus’ head. These are some pretty sweet updates for a 1986 vintage robot!


serverNext up is [tlankford01] with Linux Tutorial: Odroid U3 Server w/ Seafile Cloud. [tlankford01] walks us through setting up a file server using the Odroid, a 16 Gigabyte EMMC card, and a hard drive to hold the files. As one might expect, this tutorial covers a LAMP (Linux, Apache, MySQL, PHP) server stack. The 9 project logs take us from a bare microSD card to a full server. The Odroid’s 2 Gigabytes of ram are put to good use running the open source Seafile cloud server package. Tutorials like this deserve lots of love from the Hackaday.io community. Sometimes you just need to get a solid file server up and running. When that happens, this type of project is often just what the doctor ordered! So don’t be a lurker, head over to [tlankford01]’s page and give him a skull!


touch[Victor] gets us one step closer to an Odroid tablet with the HDMI touchscreen. HDMI touchscreen is a project to connect a 7″ 1024 x 600 LCD with a capacitive touchscreen to HDMI based computers. The heart of the project is Texas Instrument’s TFP401 panelbus DVI receiver chip. This chip makes interfacing LCD screens to HDMI or DVI video cards (almost) painless. There still is a bit of X configuration to do to get things running. [Victor] even got his Odroid running in Android with his custom screen setup. Those of us who have spent time in display an input configuration file limbo know that this is no small feat!

htpcFinally we have [darth_llamah] with Odroid-U3 HTPC. [Darth] raided his junkbox and parts drawers to build a solid home theater PC using the Odroid-U2. The U2 is a bit older than the current U3 models, but all [Darth’s] work should apply to any of the Odroid series. An old Itona case provided the frame for this hack, but it took a lot of custom work with plastic and epoxy to make everything fit. [Darth’s] software stack is the popular OpenELEC Linux build. [Darth] even setup a real “soft” power button using an ATtiny85 connected to USB and s Adafruit’s TrinketHidCombo library.

If you want to see all the Odroid projects in one place, check out our new Odroid projects list!

That’s it for this Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

LEDs Strips Tell You the Trains Aren’t Running

[James] is a frequent user of the London Underground, a subway system that is not immune to breakdowns and delays. He wanted a way to easily tell if any of the trains were being disrupted, and thanks to some LEDs, he now has that information available at a glance without having to check a webpage first.

Inspired by the Blinky Tape project at FT Engineering, [James] thought he could use the same strip of addressable LEDs to display information about the tube. A Raspberry Pi B+ gathers data from the London Underground’s TfL API and does a few calculations on the data. If there is a delay, the LEDs in the corresponding section of the strip will pulse, alerting the user to a problem with just a passing glance.

The project is one of many that displays data about the conditions you’ll find when you step outside the house, without having to look at a computer or smartphone. We recently featured an artistic lamp which displays weather forecasts for 12 hours into the future, and there was an umbrella stand which did the same thing. A lot is possible with LEDs and a good API!

Continue reading “LEDs Strips Tell You the Trains Aren’t Running”

Open Source, DIY Soldering Robot

After [Brian] starting selling his own Raspberry Pi expansion boards, he found himself with a need for a robot that could solder 40-pin headers for him. He first did what most people might do by looking up pre-built solutions. Unfortunately everything he found was either too slow, too big, or cost as much as a new car. That’s when he decided to just build his own soldering robot.

The robot looks similar to many 3D printer designs we’ve seen in the past, with several adjustments. The PCBs get mounted to a flat piece of aluminum dubbed the “PCB caddy”. The PCBs are mounted with custom-made pins that thread into the caddy. Once the PCBs are in place, they are clamped down with another small piece of aluminum. A computer slowly moves the caddy in one direction, moving the header’s pins along the path of the soldering irons one row at a time.

The machine has two soldering irons attached, allowing for two pins to be soldered simultaneously. The irons are retracted as the PCB caddy slides into place. They irons are then lowered onto the pins to apply heat. Two extruders then push the perfect amount of solder onto each pin. The solder melts upon contact with the hot pins, just as it would when soldered by hand.

The system was originally designed to be run on a Windows 8.1 tablet computer, but [Brian] found that the system’s internal battery would not charge while also acting like a USB host. Instead, they are running the Windows WPF application on full PC. All of the software and CAD files can be found on [Brian’s] github page. Also be sure to check out the demo video below. Continue reading “Open Source, DIY Soldering Robot”