[Charles] wrote in to share the project he just built for the London Hackerspace. He calls it CoolBot, and as the name indicates it’s responsible for keeping the laser cutter from overheating.
At its heart the system is a water pump. It uses a plastic storage container as a reservoir, with an outfeed from the laser tube coming in the top of the lid. [Charles] mounted a temperature sensor using a 3D printed part to anchor it in the center of the return stream. An Arduino clone uses this sensor, as well as ambient room temperature and laser tube temperature sensors to decide when to switch on the cooling pump. As with any hackerspace add-on, this wouldn’t be complete without Internet connectivity so he included an Ethernet shield in the project box. Speaking of, that box uses panel-mount connectors to keep dust and water away from the electronics. But the lid of the controller box also includes a character LCD for quick reference.
Don’t miss [Charles'] explanation of the system in the video after the break.
Continue reading “CoolBot keeps your laser cutter from overheating”
When [Bobo1on1] upgraded his Internet connection from ADSL to Fiber he ran into an issue of actually getting that speed to his desktop computer though his LAN setup. Before he had been using a telephone extension wire which ran from where the DSL entered the house, through a splitter, to his computer where the modem was located. Now that the router used by the fiber system is located at teh entry point, he has no easy way to run Ethernet cable to his computer room. Wifi is predictably slower than the 50mbit WAN connection, and he was unable to use the telephone cable as Ethernet directly.
The solution turns out to be a pair of TP-Link home plug adapters. These are designed to use your home’s mains wiring for data transfer. But [Bob] rigged it up so that they can push 224 mbits/sec over the telephone wire. Since you can’t run mains voltage through the telephone wire he had to hack a method to separate power for the devices from the data I/O. This was done with an external power supply and some passive components for filtering. The drawback is that this is half-duplex so up/down communications cannot happen at the same time.
During the gilded age, oil magnates, entrepreneurs, and robber barons would have a ticker tape machine in their study. This machine would print stock and commodity prices and chart these men’s assets climbing higher and higher. A lot has changed in 100 years, as now [Adam] can be kept apprised of what @KimKardashian, @BarackObama and @stephenfry ate for breakfast with his Twittertape machine.
Interestingly, [Adam]‘s build didn’t start off as a tarnished lump of 100-year-old brass; he built his beautiful ticker machine out of old clock movements he picked up on eBay. Even though the shiny part of the build only holds the roll of paper, it’s still a wonderful build. Right now the machine is connected to Ethernet, but he’s planning on adding WiFi and a few batteries for a completely wireless build.
Unlike the other ticker tape machine we saw this week, [Adam] did away with the loud clashing of gears and solenoids found in 100-year-old ticker machines. This ticker machine prints on cash register receipt paper and a very small thermal printer in the base. Although [Adam]‘s build doesn’t sound like two robots trading blows, there’s no ink needed and no danger of the letter wheel becoming misaligned and misspelling everything.
Check out [Adam]‘s build in action after the break.
Continue reading “Twittertape machine keeps track of your social media stock.”
It will be easy to keep your exercise routine on track if you don’t have to do anything at all to log your workouts. [Reefab] developed this add-on hardware for his exercise bike that automatically logs his workout on the Internet.
He’s using RunKeeper to store and display the workout data. They offer a token-based API which [Reefab] implemented in his Arduino sketch. The hardware to grab data from the exercise bike is quite simple to set up. A rare-earth magnet was added to the fly-wheel with a reed switch positioned next it in order to measure the number and speed of rotations. This is exactly how a consumer bicycle computer works, needing just one accurate measurement corresponding to how far the bike travels with each revolution of that wheel.
In addition to the networked-logging feature [Reefab] included a character display so you can follow your speed and distance data during the workout.
If you ever wanted your name out on the Internet, now is your time to shine. [Chris] hooked up an Arduino to the Internet and is streaming the results of combing through Twitter live to the entire world.
The SocialBot9000, as [Chris] calls his build, is an Arduino Uno connected to an Ethernet shield and an LCD character display. The firmware uses the Twitter API to search for recent posts containing the phrase, ‘socialbot9000.’ A PHP script on the Arduino does all the heavy lifting and with the great Bildr tutorial on getting the Ethernet shield up and running, [Chris] was off to the races.
Because it’s extremely doubtful that everyone on the Internet could manage typing a message into Twitter that would be correctly parsed by the SocialBot9000, [Chris] put a small form up on the build log that will correctly generate the message and take you to your Twitter account for posting. After all that was done, [Chris] decided to have some fun and set up a live feed from a camera in front of the LCD display for the world to watch.
[Sprite_TM] was tapped to build a rather large quiz buzzer system. Judging from his past work we’re not surprised that he seemed to have no trouble fulfilling the request. As the system is not likely to be used again (or rarely if it is) he found a way to finish the project that was both quick and inexpensive.
Each buzzer consists of a base, a button (both mechanical and electrical), and a couple of LEDs to indicate who buzzed in first. The mechanical part of the button uses a plastic bowl from Ikea and a wooden dowel surrounded by some pipe insulation. A momentary push switch is glued on the top of that dowel, and the insulation projects above that just a bit. This way it acts as a spring. The Dowel has been sized so that the bowl lip will hit the wooden base just as it clicks the switch.
As you can see, all of the buzzers are interlinked using Ethernet cable. The real trick here is how to read 14 buttons using just one CAT5 cable. This is done with the clever use of a 4×4 button matrix for a total of 16 buttons. The matrix also includes the LEDs for each buzzer. Since CAT5 has four twisted pairs this works out perfectly.
Looking for a more robust system thank this? Here’s a pretty nice one.
Depending on the scope of your requirements, Power over Ethernet (PoE) components can get pretty pricey. [Fire] wrote in to share a 4-port PoE solution he put together for under 20 euros (Ignore any SSL errors – we’ve checked it out, it’s safe).
The most expensive part of the build was the 8-port patch panel he purchased for 11 euros. He popped it open, wiring the first four ports for power after drilling spots for an indicator LED and the PSU. He wound the power lines through ferrite beads to hoping to dampen any interference that might occur before reassembling the panel.
In the picture above, you might notice that the panel is being powered via the first Ethernet port rather than through the barrel jack, which [Fire] said was done for testing purposes. When deployed in his network, he plans on using a regulated power supply from a junked laptop to provide electricity.
If you need to provide PoE to devices on your network, this is a great way to go about it. Using a patch panel like [Fire] has gives you the flexibility to easily wire up as many powered ports as you need without much hassle.