Hackaday’s Omaha Mini Maker Faire Roundup

The 2nd annual Omaha Mini Maker Faire wasn’t our first rodeo, but it was nonetheless a bit surprising . Before we even made it inside to pay our admission to the Omaha Children’s Museum, I took the opportunity to pet a Transylvanian Naked Neck chicken at one of the outdoor booths. The amiable fowl lives at City Sprouts, an Omaha community farming collective in its 20th year of operation. There seemed to be a theme of bootstrappy sustainability among the makers this year, and that’s great to see.

Just a few feet away sat a mustard-colored 1975 Chevy pickup with a food garden growing in its bed. This is Omaha’s truck farm, an initiative that seeks to educate the city’s kids in the ways of eating locally and growing food at home.  On a carnivorous note, [Chad] from Cure Cooking showed my companion and me the correct way to dry-cure meats using time-honored methods.

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New Part Day: STM32F7, An ARM Cortex-M7

It was announced last year, but ST is finally rolling out the STM32F7, the first microcontroller in production that is based on the ARM Cortex-M7.

The previous go-to part from the ST catalog was the STM32F4, an extremely powerful chip based on the ARM Cortex M4 processor. This chip was incredibly powerful in its time, and is still a respectable choice for any application that needs a lot of horsepower, but not a complete Linux system. We’ve seen the ~F4 chip pump out 800×600 VGA, drive a thermal imaging camera, and put OpenCV inside a webcam. Now there’s a new, even more powerful part on the market, and the mind reels thinking what might be possible.

Right now there a few STM32F7 parts out, both with speeds up to 216MHz, Flash between 512k and 1MB, and 320kB of RAM. Peripherals include Ethernet, USB OTG, SPDIF support, and I²S. The most advanced chip in the line includes a TFT LCD controller, and a crypto processor on-chip. All of the chips in the STM32F7 line are pin compatible with the STM32F4 line, with BGA and QFP packages available.

As with the introduction of all of ST’s microcontrollers, they’re rolling out a new Discovery board with this launch. It features Ethernet, a bunch of audio peripherals, USB OTG, apparently an Arduino-style pin layout, and a 4.3 inch, 480×272 pixel LCD with capacitive touch. When this is available through the normal distributors, it will sell for around $50. The chips themselves are already available from some of the usual distributors, for $17 to $20 in quantity one. That’s a chunk of change for a microcontroller, but the possibilities for what this can do are really only limited by an engineer’s imagination.

Automated Plant Watering System Uses Car Parts

[Shane] recently built an automated plant watering system for his home. We’ve seen several similar projects before, but none of them worked quite like this one. Shane’s system is not hooked into the house plumbing and it doesn’t use any off-the-shelf electronic valves.

Instead, [Shane’s] build revolves around a device that looks like it was intended to spray weed killer. The unit works sort of like a Super Soaker. The user fills the jug with water and then pumps a handle multiple times to build up some pressure inside the jug. Then a button can be pressed and the air pressure forces water out of the nozzle. [Shane] came up with a way to automate all of these mechanical motions.

First [Shane] had to find a way to pump up the bottle. He purchased a car door electronic lock actuator from eBay. It’s a pretty simple device. It’s just a DC motor with a gear box that turns the rotational motion of the motor into linear motion. This is mounted to a wooden jig and attached to the pump. A dsPIC microcontroller rotates the motor back and forth, which in turn pumps up the bottle.

The dsPic is also hooked up to a small servo. The servo is mounted to the same wooden jig as the car door actuator. A small arm is mounted to the servo so that when it rotates, the arm presses the pressure release button. This sends the water out of the bottles nozzle. [Pat] hooked up a small length of hose to the nozzle so he can direct the water into his plants. The video below demonstrates how the unit works. Continue reading “Automated Plant Watering System Uses Car Parts”

Hackaday 10th Anniversary: Jon McPhalen and the Propeller

[Jon] came out to our 10th anniversary mini-con to talk about the Propeller, and judging from his short introduction, his hacker cred is through the roof. He has a page on IMDb, and his first computer was a COSMAC. Around 1993, he heard of a small company introducing the BASIC Stamp, and like us with most new technology was incredulous this device could perform as advertised. He tried it, though, and for a few years after that, he was programming the BASIC Stamp every single day.

Having a lot of blinky light project under his belt, [Jon] was always struggling with interrupts, figuring out a way to blink an LED exactly when he wanted it to blink. A lot has changed over at Parallax since 1993, and now they’re spending time with the Propeller, an 8-core microcontroller where interrupts are a thing of the past. He showed off a huge, 10-foot tall bear from League of Legends, all controlled with a single Propeller, using 1000 LEDs to look like fire and flames.

[Jon] shared the architecture of the Propeller, and the inside of this tiny plastic-encapsulated piece of silicon is wild; it’s eight 32-bit microcontrollers, all sharing some ROM and RAM, controlled by something called a Cog that gives each micro access to the address, data, and IO pins.

When the Propeller was first released, there were a few questions of how the chip would be programmed. C isn’t great for multicore work, so Parallax came up with a language called Spin. It’s written for multicore microcontrollers, and from [Jon]’s little session in demo hell, it’s not that much harder to pick up than Python. Remember that hour or two where you learned the syntax of Python? Yeah, learning Spin isn’t a huge time investment.

Even though you can program the Propeller in C and C++, there’s a reason for Spin being the official language of the Propeller. It isn’t even that hard, and if you want to dip your toes in multicore microcontroller programming, the Propeller is the way to do it. It’s an open source chip as well so you can give it a try with an FPGA board.

Motivating Engineering Students with Microcontrollers

We see a lot of microcontroller based hacks around here, and it’s not hard to see why learning how to use microcontrollers is valuable to prospective engineeer. Unfortunately, microcontroller courses are dreaded by students since they focus on theory instead of application. In The First Lecure, [Colin] talks to a class of engineering students about how to get practical with microcontrollers.

He starts with an overview of a bomb countdown project that he used to learn the basics of microcontrollers. This started as a 555 based timer, but he ended up using a PIC18 after having issues with timing and reliability. Next, he discusses a paintball sentry gun inspired by a Hackaday post.  He finishes off some advice and gives the students some hardware: a Pickit2 programmer and a Saleae Logic Analyzer.

It’s easy to lose motivation due to the heavy focus on theory in engineering. [Colin]’s advice to start building stuff will hopefully motivate these students to take an interest in microcontrollers. We also like how he advises students to read Hackaday. Check out the full video of the lecture after the break.

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The coming age of ARM chips for the hobbyist

The days of the 8 bit Arduino may be quickly coming to a close. Sure, there will always be a place for AVRs in blinking LEDs and turning on relays, but for doing anything cool – playing MP3s, driving LCD displays, or running a CNC machine – you need the power of a 32 bit chip. [Brian Carrigan] put up a great tutorial on getting started with these bigger, more powerful micros and moving beyond what is possible with an 8 bit PIC or AVR.

These new 32 bit chips are much more powerful, but aren’t exactly hobbyist friendly. Most of the ARM chips we’ve found are stuffed into very fine pitch QFN or QFP packages that require a reflow oven to solder to a board. In fact, we can only find one through-hole Cortex M0 chip that is suited for breadboard development. This doesn’t make it easy to whip up a circuit in a few hours, so builders needing a very powerful microcontroller will be more dependent on dev boards.

Already there are a good number of ARM-based 32 bit dev boards available including the offerings from Leaf Labs, the extremely inexpensive STM Discovery boardKinetis KL25Z Freedom Board, the outrageously powerful BeagleBone, and the perpetually delayed Arduino (over) Due.

None of these boards are particularly new developments; they’ve all been around the block once or twice. However, there are many more options for 32 bit development than the current 8 bit PIC and AVR holy war. We’re going to turn the comments over to Hackaday readers with the following questions: what supersized dev board are you rolling with? What’s good for a beginner, and what should they watch out for?

Making an RF controlled light switch work with IR


[Gary] had an RF triggered light switch kicking around, and wanted to find a way to control his lights using a home theater remote. The switch, which he bought from RadioShack years ago, came with a simple remote that uses two buttons to toggle the lights on and off. While you might think that switching from RF to IR control would be a step backwards, [Gary] really just wanted to consolidate remotes more than anything else.

He designed a circuit board specifically for interacting with the remote half of his RF controller. It sports a PIC16F628A micro controller, which is tasked with processing IR commands from his home theater remote and triggering the lights when requested.

The code he developed for the project is relatively simple, but very useful all the same. When his board is powered on, it stores the first IR code it receives, then retains it as long as it stays powered on. This lets [Gary] use any button on his remote to turn the lights on and off, without any IR codes permanently defined in software.

As you can see in the video below, the modified switch works just as intended, saving [Gary] from having to walk all the way to the light switch when it’s time to fire up a movie.

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