Tiny BLE UART Makes Bluetooth Low Energy Simple

Last time I talked about the internals of how Bluetooth Low Energy (BLE) handles data. I mentioned that the way it is set up is meant to conserve power and also to support common BLE devices like heart rate monitors. On the other hand, I also mentioned that you often didn’t need to deal with that because you’d use an abstraction layer.

This time, I want to show you how I used the Hackaday special edition Tiny BLE (from Seeed Studios) and its mbed library to do a quick simple BLE project. If you didn’t read the first part, don’t worry. The abstraction is so good, you probably won’t have to unless you want to circle back around later and get a more detailed understanding of what’s happening under the covers.

I wanted something simple for an example so you could build on it without having to remove much code. For that reason, I decided to allow my phone to control the state of a three-color LED via BLE. To do that, I’m going to use a virtual UART and some off-the-shelf phone software. The whole thing won’t take much code, but that’s the point: the abstraction makes BLE relatively simple.

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Disposable Camera Flashes Live Again

Aiming to improve the image quality of the photos on his website, [Jean] needed an external flash unit.

ep-026-0280-960Say what you will about disposable cameras, but the fact that they were mass-produced, and are now nearly obsolete, means they are an absolute treasure trove of electronics components when you can buy them for dirt cheap. So [Jean] decided to turn a few of his disposable cameras into an external flash system for his DSLR (Translated).

He started by taking apart a Kodak digital camera and examining the circuit board. KEY1 enables the charging of the capacitor (the camera ON switch) and SW1 is located under the shutter-release.

Now all he had to do was replace SW1 with an electronic trigger from his DSLR.

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Hyperloops And Robot Cars, A Glimpse Into The Future

His mobile blooped at him with one of those noises a company spent money to get. A timer started on the screen as he rushed to put his shoes on. He finished and pushed open his door, running down the stairs two to a bound. By the time he reached the bottom of the stairs he had his backpack slung over both shoulders, which he mentally cursed himself for since he’d just have to take the dang thing off again.

It was morning on January first, and he was due at his parent’s house for a new year’s dinner fifteen hundred miles away. He should have booked a plane weeks ago, but now the Loop was his only option. The Loop didn’t really have peak rates, and while the plane would be a little faster, more direct, and cheaper IF he had remembered to book it in time, the Loop would take him the same distance today. Plus, the seats were comfier. They reclined nicely, and he intended to nap on the way. Hopefully, by the time he got there, the bleariness from last night’s celebration would be undetectable by parental senses.

He locked the door to his apartment complex, a reassuringly square assembly from the seventies, and walked to the sidewalk where a friendly light blue car waited for him. When he got close, his mobile vibrated and made another distressingly cheery noise. The doors of the car swung open opposite of each other to expose the space inside. The car displayed two rows of inward facing bench seats, a panoramic row of windows around the entire perimeter of the vehicle, and… yes, his nose was telling him before his eyes fixed on it, a very unsettling amount of vomit in the center of the floor.

He turned around, a bit squeamish, and took out his mobile. He navigated through the controls. Where is the menu option? What year is it now? Why is this still hard? Three awkward menus deep and he finally found and selected the option to let the dispatch know the car had an issue which made it uninhabitable. The car immediately began to chirp warnings and the doors soon started to close. In a moment, a human somewhere in the city would be looking at a video of the inside of the car, determining him a liar or not. As expected, a few seconds later, the little car began to drive off. The lights on the rear of the car turned from bright red to the yellow amber of headlights as it decided its front would be its back. It drove off to the dispatch center for cleaning and repair. Someone would be eating a 100 dollar cleaning bill today. He didn’t feel sorry for them.

His phone began to vibrate. He picked it up to answer a call from a bored customer service representative who was trying hard to sound earnest. “Sorry for the trouble sir, the ride today will be free. We have another car on its way”

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Fail Of The Week: Always Check The Fuse

[Tomas] at Umeå Hackerspace in Sweden had some broken audio equipment, including a Sharp CD player/amplifier. What went wrong when he tried to fix it is a fail story from which we can all learn.

The device worked – for about a second after being turned on, before turning itself off. That’s a hopeful sign, time to start debugging. He took the small-signal and logic boards out of the circuit, leaving only power supply and amplifier, and applied the juice.

Magic blue smoke ensued, coming from the amplifier. Lacking a suitable replacement part, that was it for the Sharp.

On closer inspection it emerged that the previous owner had bypassed the power supply fuse with a piece of copper wire, Evidently they had found the fuse to be blowing too often and instead of trying to fix the problem simply shot the messenger.

We have all probably done it at some time or other. In the absence of a replacement fuse we may have guestimated the number of single strands required to take the current, or used a thin strip of foil wrapped around the fuse body. And we’ll all have laughed at that meme about using a spanner or a live round as a fuse.

So if there’s a moral to this story, it’s to always assume that everyone else is as capable as you are of doing such a dodgy fix, and to always check the fuse.


2013-09-05-Hackaday-Fail-tips-tileFail of the Week is a Hackaday column which celebrates failure as a learning tool. Help keep the fun rolling by writing about your own failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

Automatic Pneumatic Harmonica

A wise man once said “If all you’ve got is a cute desktop compressor and some solenoid valves, everything looks like a robotic harmonica.” Or maybe we’re paraphrasing. Regardless, [Fabien-Chouteau] built a pneumatic, automatic harmonica music machine.

It’s actually an offshoot of his other project, a high-speed candy sorting machine. There, he’s trying to outdo the more common color-sensor-and-servo style contraptions by using computer vision for the color detection and a number of compressed-air jets to blow the candy off of a conveyor belt into the proper bins.

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Autonomous Tractor Brings In The Harvest

[Matt Reimer] is a farmer in Southwestern Manitoba, Canada. It’s grain country, and at harvest time he has a problem. An essential task when harvesting is that of the grain cart driver, piloting a tractor and grain trailer that has to constantly do the round between unloading the combine harvester and depositing the grain in a truck. It’s a thankless, unrelenting, and repetitive task, and [Matt]’s problem is that labour is difficult to find when every other farmer in the region is also hiring.

His solution was to replace the driver with a set of Arduinos and a Pixhawk autopilot controlling the tractor’s cab actuators, and running ArduPilot, DroneKit, and his own Autonomous Grain Cart software. Since a modern tractor is effectively a fly-by-wire device this is not as annoying a task as it would have been with a tractor from several decades ago, or with a car. The resulting autonomous tractor picks up the grain from his combine, but he reminds us that for now it still deposits the harvest in the truck under human control. It is still a work-in-progress with only one harvest behind it, so this project is definitely one to watch over the next few months.

Writing from the point of view of someone who grew up on a farm and has done her share of harvest-time tractor driving it’s possible to see both the strengths and weaknesses of an autonomous grain cart. His fields on the Canadian prairie are very large and flat, there is plenty of space and the grain makes its way from the field to the elevator in a truck. To perform the same task in the smaller and irregular fields of southern England for example with a mile round trip down country lanes to the grain store would be a much greater challenge. Aside from that it’s worth noting that his John Deere is a 220hp 4WD workhorse that is capable of going over almost any terrain on a farm with very few obstacles able to stop it. This thing can do serious damage to life and property simply by running it over or driving straight through it, so safety has a dimension with an autonomous tractor in a way that it never will with for example a vacuum cleaner or even a lawnmower.

Those observations aside, this kind of technology undeniably represents a step change in farming practice on a par with the move from horse power to tractors in the first half of the last century. However the technological barriers that remain end up being solved, it’s likely that you’ll see plenty more machines like this in the fields of the future.

The video below the break shows the autonomous grain cart in action. Plenty of big-sky tractoring action, and for those of you unfamiliar with farming it should provide some understanding of the task of getting grain from combine to store.

We’ve talked about robotic farming more than once here at Hackaday. The gantry-based Farmbot, the six-legged Prospero robot farmer, or another hexapod confusingly also called Farmbot, for example. But these have all been hacker’s solutions to the problem using the concepts with which they are familiar. What makes [Matt]’s project different is that it is a farmer’s solution to a real farming problem by automating the machinery he already uses to do the job. Farmers have been doing what we would now call hacking at the hardware of their craft since time immemorial, [Matt]’s work is just the latest manifestation of a rich heritage.

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IR Rework Station

Modern surface mount components often need special tools for rework. However, those tools can be expensive. [Michael Skrepsky] wanted an infrared rework station, but didn’t like the price. So he built his own.

According to [Michael] he used a lot of scrap in the construction. . He used K-type thermocouples, optotriacs, triacs, a 20×4 display and, of course, an Arduino. An old bathroom heater, along with a 600W and 100W halogen bulb work as heaters.

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