Easy LCD Control For Arduino Mega

July 24, 2013 by Mike Szczys 10 Comments

arduino-mega-easy-lcd-adapter

[Andy Brown] wrote in to show off the TFT LCD adapter he’s been working on for connecting inexpensive displays to an Arduino Mega.

These TFT LCD screens can be picked up on eBay for a few dollars. But they’re more suited for 16-bit microcontrollers which operate at 3.3V levels. His adapter board, which plugs directly into the Mega’s dual-row pin header, makes it easier to control these with an 8-bit chip that is running at 5V.

There’s a couple of things that make this happen. First off, he’s included level converter chips to managed the 3.3V/5V issues. Second, he uses latch chips to translate eight pins on the Arduino Mega to sixteen pins on the display. Those chips have a latch pin which holds the output values in memory while the input pins are changed. He manages to drive the latch on just one of the chips using the chip select (CS) line called for by the LCD protocol. This means you don’t lose any extra pins.

Another way to uses the displays with Arduino is to use a smart controller for TFT screens.

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Arduino Cellphone

July 20, 2013 by Mike Szczys 27 Comments

OLYMPUS DIGITAL CAMERA

The fact that you can build a cellphone around an Arduino is pretty neat. But we’re drawn to this project more as a testament to the advancement of hobby electronics. An [Average Joe] can build this thing with a minimum or background knowledge and without breaking the bank. Wow.

Of course this isn’t the first DIY cellphone we’ve come across. One of our favorites is this one which resides on a home etched PCB. There was even another Arduino offering with similar components back in September. But the one seen above really pulls it all together into a package that is usable for everyday life. The components include and Arduino Uno, GPRS shield from Seeed Studios, a TFT touch screen, Lithium battery and charging circuit, and a few other bobbles. All of it is mounted inside of a 3D printed case.

A simple phone calls for a simple UI and that’s included as well. The main menu has two buttons, one for placing a call, the other for sending a text. From there you get the virtual keypad seen above for typing out the phone number or composing a message.

[Thanks Victorzie]

Hacking Quiz Game Buttons To Add A Central Controller

July 18, 2013 by Mike Szczys 5 Comments

hacking-quiz-game-hardware

The four colored buttons seen above are a product made by Learning Resources. They flash and make noise when pressed and are meant for quiz-show style games in the classroom. The problem is that they don’t use a central controller, so it’s up to the person running the game to judge who rang in first. [Kenny] fixed that issue by building his own controller which is housed in that black project box.

He went with an Arduino Uno board. It fits in the project box and has no problem monitoring all of the buttons and triggering their sound and lights when necessary. There are two telephone jacks (RJ11 connectors) on either side of the controller. He also cracked open each button, cutting some traces on the PCB in order to patch the signals into connectors he added to the housing.

The video after the break shows the system in action, In addition to illuminating the first button to ring in there are LEDs on the box that indicate who was 2nd, 3rd, and 4th in line.

If you don’t want to purchase buttons try making your own with some cheap plastic bowls.

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Robot Theater Isn’t So Much For The Actors As The Stagehands

July 17, 2013 by Mike Szczys 24 Comments

robot-theater

[Chris Rybitski] developed this low-profile robot to help move scenery on stage. The test footage shows it to be spry and able to move hundreds of pounds of cargo. The demo shows the addition of a wooden platform about twice the length of the metal chassis with casters at each end to support the extra weight. It seems to have no problem moving around with the weight of a couple of human passengers on board.

Crafty systems for changing huge sets has long made the theater a natural breeding ground for hacks. Balanced turn tables, rails systems, and the like are common place. But we think this has a ton of potential. Right now the electronics seem convoluted, as there is an Arduino running the motors which connects to the LAN using an Ethernet shield and that Linksys wireless router.

We think he should patch directly into the serial port of the router. If he loads DD-WRT or OpenWRT he can easily make the remote control a web interface. We also wonder about the possibility of making it a line-follower that can precisely position itself automatically using patterns on the floor.

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Filtering Out Mains Hum From ADC Samples

July 15, 2013 by Mike Szczys 19 Comments

Hum_filter

A little light reading means something different to us than it does to [Hamster]. He’s been making his way through a book called The Scientist and Engineer’s Guide to Digital Signal Processing written by [Steven W. Smith, Ph.D]. Being the hacker type, a million different uses for the newfound knowledge popped to mind. But as a sanity check he decided to focus on a useful proof of concept first. He’s come up with a way to filter out the mains hum from Analog to Digital Converter samples.

Mains hum is all around us; produced by the alternating current in the power grid that runs our modern lives. It’s a type of interference that can be quite problematic, which is on reason why we see EMF sensor projects from time to time. Now you can filter that ambient interference from your projects which take readings from an ADC. This would be quite useful for applications which measuring teeny signals, like ECG hacks.

[Hamster] did a pretty good job of presenting his demonstration for the uninitiated. He even provides examples for Arduino or FPGA projects.

A Robotic Tattoo Artist

July 15, 2013 by Brian Benchoff 32 Comments

tattoo

Here’s something we thought we’d never see: a robot that turns a computer drawing into a tattoo on the user’s arm.

The basic design of the robot is a frame that moves linearly along two axes, and rotates around a third. The tattoo design is imported into a 3D modeling program, and with the help of a few motors and microcontrollers a tattoo can be robotically inked on an arm.

Since the arm isn’t a regular surface, [Luke] needed a way to calibrate his forearm-drawing robot to the weird curves and bends of his ar. The solution to this problem is a simple calibration process where the mechanism scans along the length of [Luke]’s arm, while the ‘depth’ servo is manually adjusted. This data is imported into Rhino 3D and the robot takes the curve of the arm into account when inking the new tat.

Right now [Luke] is only inking his skin with a marker, but as far as automated tattoo machines go, it’s the best – and only – one we’ve ever seen.

[Massimo] Talks About Arduino Clones

July 15, 2013 by Brian Benchoff 60 Comments

pick one

Back in 2005, the Arduino was just a twinkle in they eyes of [Massimo Banzi] and the other core developers. Since then, you can’t go to any electronics site without hitting something beginning with ‘ard~’ or ending with ‘~duino’. The platform has become so popular, people everywhere are piggybacking on the name to the point of trademark infringement or simply outright counterfeiting one of the many official Arduino boards. Now [Massimo] has something to say about these clones, ripoffs, derivatives, and ‘duino-compatible boards.

On the list of things bad for the open source ecosystem, [Massimo] points to direct clones of existing Arduino boards. While these boards are electrically identical to officially licensed boards, they simply don’t support the Arduino project financially and usually don’t contribute to the existing libraries and code. Even worse are counterfeits; these boards copy the trademarks of the Arduino project – sometimes terribly given the three examples above (guess which one is the real one) – and directly profit off of the Arduino project without giving any support in return.

There are other veins of Arduino that [Massimo] considers more acceptable. Arduino-compatible boards, seen by the dozen over on Kickstarter, usually add something of their own, be it a radio chip, or an entirely different microcontroller. Derivatives, like Teensy and Adafruit’s Flora actually bring new things to the table with improved hardware and new and interesting libraries.

As far as counterfeits and clones go, we can’t agree more with what [Massimo] has to say. You have to admire the folks in the Arduino project being so open about their creations and admiring the Arduino derivatives that bring some new hardware to the table. Then again, that’s the lesson of the Arduino project; you can make hardware open source and still be outrageously popular.