The JavaScript Of Things

September 3, 2013 by 57 Comments

Espruino

There are a ton of people out there that can program in JavaScript, but give them an embedded device, and they’re up the creek without a paddle. Not anymore, that is, thanks to [Gordon]’s wonderful Espruino, a JavaScript interpreter for ARM microcontrollers. Oh, it’s also a very capable dev board that has more than enough power to turn just about any project you can imagine into reality.

On board the Espruino is an ARM Cortex M3 in the form of an STM32 chip, 256kB Flash, 48kB of RAM, and a ton of PWM and ADC pins to go along with 2 SPI ports, 2 I2C ports, and 2 DACs. It’s a very capable piece of hardware, and if you’re looking to build anything, it would be hard to pick a better general purpose dev board.

[Gordon] has put his board up on Kickstarter, and since it’s already been successfully funded, he’ll be releasing the hardware and software sources under an Open Source license. If you’ve ever wanted to run JavaScript on an ARM board, it looks like Espruino is just the ticket.

A Weekend Trip To Verify General Relativity

September 3, 2013 by 77 Comments

8 years ago, for the 100th anniversary of the theory of relativity [Tom] decided to test the general theory of relativity.

As he was going to Mt Rainier (5400ft high) with his children for the weekend, he brought in his van 3 cesium clocks while leaving other atomic clocks at his home for comparison. The theory behind the test is that if you’re are at higher altitudes, then your speed (in a galactic coordinate system) is higher than the one you’d have at sea level and therefore time would go “slower” than at lower altitudes.

[Tom] brought 400 pounds of batteries, 200 pounds of clocks and left his car turned on during his 2 days stay in the ‘Paradise Lodge’. He used 120V DC to AC converters and chose to bring 3 cesium clocks to have a triple redundant  setup. When he came back home, he had the good surprise of finding a time difference of 23ns. This is a great application for those rubidium sources you’ve been scavenging.

[Thanks Indyaner via Reddit]

Finally, A Practical Use For The Leap

September 3, 2013 by 15 Comments

Robots used in laparoscopic surgery are fairly commonplace, but controlling them is far from simple. The usual setup is something akin to a Waldo-style manipulator, allowing a surgeon to cut, cauterise, and stitch from across a room. There is another way to go about this thanks to some new hardware, as [Sriranjan] shows us with his Leap-controlled surgery bot.

[Sriranjan] isn’t using a real laparoscopic surgery robot for his experiments. Instead, he’s using the Le-Sur simulator that puts two virtual robot arms in front of a surgeon in training. Each of these robotic arms have seven degrees of freedom, and by using two Leap controllers (one each in a VM), [Sriranjan] was able to control both of them using his hands.

We’ve seen a lot of creative applications for the Leap sensor, like controlling quadcopters, controlling hexapod robots, and controlling more quadcopters, but this is the first time we’ve seen the Leap do something no other controller can – emulating the delicate touch of a surgeon’s hand

Continue reading “Finally, A Practical Use For The Leap” →

Couch To 5K With 1K To Spare

September 3, 2013 by 9 Comments

In a market full of Fitbits, Misfits, and Fuelbands, it’s easy to get carried away with sophisticated personal fitness tracking technology.  That’s why [André] took a totally different approach with his super simple run tracking device, the C25K machine.

C25K stands for “Couch to 5k” which is a slimmed down exercise schedule designed to gradually bring people who have otherwise no exercise routine up to a level of fitness where they can run a 5k in just 9 weeks.  To keep participants from wearing themselves out too early, the routine specifies a sequence of running and walking periods to be completed in series on specific days.  Though simpler than most fitness plans, it’s still a lot to keep track of especially when you’re sweating so hard you can barely see your stopwatch.

André found a solution using a bare-bones circuit based on the ATTiny2313.  After loading the C25k calendar into its firmware (which takes up less than half of its 2K of flash), he needs only to toggle the dipswitch to select the appropriate day of the program, and the little device (scarcely larger than a key fob) will beep to let him know to switch from running to walking or back again.

Definitely a great project for any hobbyist looking for a geeky way to get in shape.

A Pick And Place Tool From Medical Equipment

September 3, 2013 by 41 Comments

neb

A vacuum tool is an invaluable tool if you’re working with tiny SMD parts, and even with tweezers you might have a hard time placing these nearly invisible components on their pads for soldering. One tool that’s really great for these parts is a vacuum pen, usually made from an old aquarium air pump. [Jon] may have found a much more suitable piece of equipment to scavenge for a vacuum pen build – a nebulizer.

Nebulizers provide asthmatics with low pressure, low volume air to atomize medication for inhalation. Inside the nebulizer is a small diaphragm pump, just like the small aquarium pump teardowns we’ve seen. In just five minutes, [Jon] tore his thrift store nebulizer apart and reversed the flow of air, turning something that blows into something that sucks.

After the suction part of the build was finished, [Jon] needed a way to pick up small components. He did this by blunting a large hypodermic needle and fastening it to the end of a Bic pen with heat shrink tubing. After drilling a small hole in the pen body, he had a very nice looking SMD vacuum pump.

Grow Your Own Coffee Beans

September 2, 2013 by 47 Comments

beans

Unlike T-shirts, sneakers, cell phones, children’s toys, software, appliances, virtually everything made of plastic, and food, people really seem to care about who makes their coffee. Instead of buying guilt-free free trade coffee, [spikec] over on Instructables decided to actually do something to uproot the evils of consumerism. He’s making his own coffee, at home, with a real coffee plant.

[spikec] bought a coffee plant a few years ago off eBay. Coffee plants are actually trees, and with careful pruning they can be maintained to a reasonable size. But what about the weather? Well, for [spikec], who lives in the 7a USDA hardiness zone – a strip that runs from southern New Jersey to the Texas panhandle – he just brings the plant inside when it’s cold.

Once the coffee fruit turns ripe, [spikec] picks the beans, husks the fruit, and puts the beans in a dehydrator. From there, it’s a trip through a small coffee roaster and into a french press.

[spikec] only harvested about a half pound of beans. That’s still very impressive for growing a bonsai coffee tree a thousand miles outside its native range.

Monitoring A Coffee Pot With An Arduino

September 2, 2013 by 25 Comments

coffee graph

Coffee has always been an important part of the internet; the first webcam ever was in the Trojan Room of the Cambridge University Computer Laboratory to monitor the contents of a coffee pot. Now, instead of webcams, we have Arduinos and a bathroom scale. Not particularly similar to a webcam, but more than enough to keep track of how much coffee is currently available at DoES Liverpool.

Being a techy workshop/studio, coffee is always in short supply at DoES Liverpool. Instead of getting up and checking the pot, [Patrick] thought it would be a good idea to monitor the contents of a coffee pot online. He’s doing this with a bathroom scale underneath the coffee machine connected to an Arduino Ethernet module. By measuring the weight of the coffee pot and subtracting the known empty weight, [Patrick] can get a pretty good idea of how much coffee is left in the pot, and how long the coffee has been sitting there.

The data from the Arduino is fed to an Xively feed that displays the current status of the coffee machine on any computer with an Internet connection. Far more sophisticated than the first webcam ever, and a very useful tool for everyone at DoES Liverpool.