Posts with «atmega» label

Balancing Robot Needs Innovative Controller and Motor

A self-balancing robot is a great way to get introduced to control theory and robotics in general. The ability for a robot to sense its position and its current set of circumstances and then to make a proportional response to accomplish its goal is key to all robotics. While hobby robots might use cheap servos or brushed motors, for any more advanced balancing robot you might want to reach for a brushless DC motor and a new fully open-source controller.

The main problem with brushless DC motors is that they don’t perform very well at low velocities. To combat this downside, there are a large number of specialized controllers on the market that can help mitigate their behavior. Until now, all of these controllers have been locked down and proprietary. SmoothControl is looking to create a fully open source design for these motors, and they look like they have a pretty good start. The controller is designed to run on the ubiquitous ATmega32U4 with an open source 3-phase driver board. They are currently using these boards with two specific motors but plan to also support more motors as the project grows.

We’ve seen projects before that detail why brushless motors are difficult to deal with, so an open source driver for brushless DC motors that does the work for us seems appealing. There are lots of applications for brushless DC motors outside of robots where a controller like this could be useful as well, such as driving an airplane’s propeller.

Filed under: robots hacks

Tiny Radio Tracks Your Balloons

The name of the game in rocketry or ballooning is weight. The amount of mass that can be removed from one of these high-altitude devices directly impacts how high and how far it can go. Even NASA, which estimates about $10,000 per pound for low-earth orbit, has huge incentives to make lightweight components. And, while the Santa Barbara Hackerspace won’t be getting quite that much altitude, their APRS-enabled balloon/rocket tracker certainly helps cut down on weight.

Tracksoar is a 2″ x .75″ x .5″ board which weighs in at 45 grams with a pair of AA batteries and boasts an ATmega 328P microcontroller with plenty of processing power for its array of on-board sensors. Not to mention everything else you would need like digital I/O, a GPS module, and, of course, the APRS radio which allows it to send data over amateur radio frequencies. The key to all of this is that the APRS module is integrated with the board itself, which saves weight over the conventional method of having a separate APRS module in addition to the microcontroller and sensors.

As far as we can see, this is one of the smallest APRS modules we’ve ever seen. It could certainly be useful for anyone trying to save weight in any high-altitude project. There are a few other APRS projects out there as well but remember: an amateur radio license will almost certainly be required to use any of these.

Filed under: radio hacks

Reverse-Engineering a Superior Chinese Product

It makes an Arduino look like a 555.  A 364 Mhz, 32 bit processor. 8 MB RAM. GSM. Bluetooth. LCD controller. PWM. USB and dozens more. Smaller than a Zippo and thinner than corrugated cardboard. And here is the kicker: $3. So why isn’t everyone using it? They can’t.

Adoption would mandate tier after tier of hacks just to figure out what exact hardware is there. Try to buy one and find that suppliers close their doors to foreigners. Try to use one, and only hints of incomplete documentation will be found. Is the problem patents? No, not really.

[Bunnie] has dubbed the phenomenon “Gongkai”, a type of institutionalized, collaborative, infringementesque knowledge-exchange that occupies an IP equivalent of bartering. Not quite open source, not quite proprietary. Legally, this sharing is only grey-market on paper, but widespread and quasi-accepted in practice – even among the rights holders. [Bunnie] figures it is just the way business is done in the East and it is a way that is encouraging innovation by knocking down barriers to entry. Chinese startups can churn out gimmicky trash almost on whim, using hardware most of us could only dream about for a serious project.

He contrasts this with the West where only the big players like Apple and Google can step up to the plate. Everyone else is forced to use the embarrassingly obsolete hardware we are all familiar with. But [Bunnie] wants to get his foot in the door. “Can we find a way to still get ahead, yet still play nice?” he asks.

Part of his solution is reverse engineering so that hardware can simply be used – something the EFF has helped legally ensure under fair use. The other half is to make it Open Source. His philosophy is rooted in making a stand on things that matter. It is far from a solid legal foundation, but [Bunnie] and his lawyers are gambling that if it heads to a court, the courts will favor his side.

The particular board targeted is the one described above – the MT6260. Even spurred by the shreds of documentation he could gather, his company is a 2-man team and cannot hope to reverse engineer the whole board. Their goal is to approach the low-hanging fruit so that after a year, the MT6260 at least enters the conversation with ATMega. Give up trying to use it as a phone; just try to use like the Spark Core for now.

He is already much of the way there. After telling you what is on board and why we would all want to use it, [Bunnie] shows how far he has gone to reverse engineering and describes his plans for the rest. From establishing an electronic “beachhead” base of operations to further probe the device, to X-rays, photos, diagrams and the beginnings of an OS. If this type of thing interests you at all, the meticulous approach and easy-reading of this tech teardown will surely impress and inspire you. Every step of progress requires a new hack, a new solution, a new ingenious way to pry information out.

We’ve featured some awe-inspiring reverse engineering attempts in the past, but this is something that is still new and relevant. Rather than only exploit his discoveries for himself, [Bunnie] has documented and published everything he has learned. Everyone wins.

Thanks [David] for the tip.

Filed under: Cellphone Hacks, hardware, slider, teardown

Handheld Game System Powered by Arduino

These days, it’s easy enough to play games on the go. If you have a smart phone, you are pretty much set. That doesn’t mean you can’t still have fun designing and building your own portable gaming system, though.

[randrews] did just that. He started out by purchasing a small memory LCD display from Adafruit. The screen he chose is low power as far as screens go, so it would be a good fit for this project. After testing the screen with a quick demo program, it was time to start designing the circuit board.

[randrews] used Eagle to design the circuit. He hand routed all of the traces to avoid any weird issues that the auto router can sometimes cause. He made an efficient use of the space on the board by mounting the screen over top of the ATMega chip and the other supporting components. The screen is designed to plug in and out of the socket, this way it can be removed to get to the chip. [randrews] needs to be able to reach the chip in order to reprogram it for different games.

Once the board design was finished, [randrews] used his Shapeoko CNC mill to cut it out of a copper clad board. He warns that you need to be careful doing this, since breathing fiberglass dust is detrimental to living a long and healthy life. Once the board was milled out, [randrews] used a small Dremel drill press to drill all of the holes.

The final piece of the puzzle was to figure out the power situation. [randrews] designed a second smaller PCB for this. The power board holds two 3V coin cell batteries. The Arduino expects 5V, so [randrews] had to use a voltage regulator. This power board also contains the power switch for the whole system.

The power board was milled and populated. Then it was time to do some measurements. [randrews] measured the current draw and calculates that he should be able to get around 15 hours of play time using the two 3V coin cell batteries. Not bad considering the size.

[via Reddit]

Filed under: Arduino Hacks
Hack a Day 23 Jun 06:00

640×480 VGA On An Arduino

There are dozens, if not hundreds of examples around the Intertubes of an Arduino generating a VGA video output. The Arduino isn’t the fastest chip by far, and so far, all of these VGA generation techniques have peaked out at lower resolutions if you want to control individual pixels.[PK] has an interesting technique to generate 640×480 VGA at 60 frames per second without overclocking. It’s hacky, it’s ugly, but surprisingly, it actually works.

The VGA standard of 640×480 @ 60 fps requires pixels to be clocked out at 25.175 MHz, and the ATMega chips found in Arduinos top out at 20 MHz. [PK] wanted to generate VGA signals without overclocking, He did this by doubling the clock frequency with digital logic. The ATMega generates a clock, an inverter delays that clock so it is 90 degrees out of phase, and the two clocks are XORed, doubling clock output of the micro. It produces a very ugly square wave at 32 MHz – an error of 27% compared to the VGA spec. Somehow it still works.

With a hilariously out of spec clock, the rest of the project was pulled together from [Nick Gammon]‘s VGA library, a 16×16 font set, and a project from [lft]. Video below.

Filed under: Arduino Hacks

Autonomous robot that returns to charging station when battery runs low

Primary image

What does it do?

Drive around until battery runs low, then it will look for the charging station to get some juice



Cost to build


Embedded video

Finished project



Time to build

600 hours


URL to more information


1000 grams

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Permaduino makes your Arduino projects permanent (video)

Arduinos are fun to tinker with, but there's one problem. Once you've built something cool, you pretty much have to tear it down to use your board for another project. Sure, you can always buy multiple Arduino boards or proto shields, but what if you want to turn your creation into something a bit more permanent and a lot more compact? Say hello to Permaduino, a small battery-powered Arduino prototype board that just launched on Indiegogo. It features an Atmega328P (natch), two AAA battery holders with a 3 to 5V DC-DC converter (up to 180mA), a 25-column breadboard with VCC and ground, plus FTDI, AVR-ISP and USB interfaces. Best of all, Permanuino conveniently fits inside a standard 8mm videotape case (as long as you don't mount large components on that breadboard). Interested? Hit the break for the Indigogo link and campaign video.

Filed under: Misc


Source: Permaduino (Indiegogo)

Engadget 20 Jan 17:09

Atmel RF ATmegas


Has anyone attempted using these? I was wondering how hard it would be to use them with the arduino bootloader for my as-yet-not-started RC system project (I will get round to it soon, hopefully). The Zigduino seems to use them, and they've supplied a library to operate the in-built radio. I'm just wondering whether I'd have to be careful with PCB layout etc. to avoid interference.

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Let's Make Robots 12 Jan 14:49

Spider controller now sold by SparkFun

The DAGU Red back Spider controller is an Arduino Mega (1280) compatible controller that is especially designed for driving a large number of servos. All 70 I/O pins are terminated in servo compatible 3pin male headers as well as the standard female header and the power supply is a switchmode power supply delivering 5V @ 3A from an input voltage of 7V - 32V.

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Let's Make Robots 26 Oct 17:41
1280  48  advertising  arduino  atmega  controller  dagu  fun  robot  servos  spark  sparkfun  spider  

ATMega AVR Pin Sticker

Okay, so I was bored and flipping through Adafruit tonight and I saw that they had stickers like these for $3/10.  Not that I want to take money out of Limor's pocket, but I thought I'd share these with my LMR kin:

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Let's Make Robots 02 Jun 03:30
168  328  arduino  atmega  avr  compatible  throughhole