The I2C Programmable NFC Tag

NFCNFC tags are cool, but programming them to do your bidding – whether unlocking your computer, making an Arduino vending machine, or a smart home application – requires using an NFC device to program the tag over the air. An NFC tag programmable with any ‘ol microcontroller would certainly have some interesting applications, and Elecfreaks’ DNFC tag is just the thing to test out these ideas.

While NFC tags are reprogrammable, reprogramming them requires an NFC controller, be that through a dedicated hardware, a phone, or an Arduino shield. The DNFC tag is reprogrammable with a microcontroller with an I2C interface thanks to TI’s RF430CL330H dynamic NFC transponder IC. It still does everything you would expect from a NFC tag – MIFARE compatible. NDEF reading and writing, and everything else – but you can program it through an Arduino, Pi, or any other board with an I2C interface.

TI has an app note on using the chip inside the DNFC for automatic Bluetooth pairing, and Elecfreaks themselves have a few use cases in mind that include putting WiFi credentials on an Arduino board without putting the SSID in code and other Internet of Things™ applications. We’re thinking this is one of those devices that is eminently useful, but for something we just can’t think of off the top of your head. If you’ve got an idea for how to use an I2C programmable NFC tag, drop a note in the comments.

Elecfreaks is doing an Indiegogo campaign for the DNFC, $13 for one. I picked one up, but it’s flexible funding, so buy it or don’t. I don’t care.

Art-O-Matic Is Spirograph’s Young Hip Offspring

Art-O-Matic automatic spirograph

Some of our more senior experienced readers may remember a toy called the Spirograph. In case you don’t, it’s a geometric shape drawing toy. The way it works is a plastic disc with gear teeth around the perimeter and various holes on its face is spun around a plastic ring with gear teeth on the inside. A pencil is inserted in one of the holes in the disc and, when spun around the inside of the ring, draws different complex shapes called hypotrochoids.

 Art-O-Matic automatic Spirograph

This was fun enough to keep a kid entertained for a few minutes. It took a while to make a complete shape and sometimes it was easy to mess up (especially if the hole chosen for the pencil was near the outside of the disc). [Darcy] thought it would be neat to combine the Spirograph’s drawing style with modern technology. The result is called the Art-O-Matic and it draws some pretty wild art, you guessed it, automatically.

Click past the break for more!

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Homemade Alarm System Doesn’t Lack Features

alarm system

To many of us, our garage (or workshop) is probably one of the most important parts of the house. If a burglar broke in, we’d likely be more worried about our tools! [Ron Czapala] decided he needed an alarm system in his garage to keep his stuff safe, so he decided to build one from scratch.

The system makes use of a Parallax 4×4 keypad membrane, a MCP23008 port expander, a Parallax Propeller, a LCD screen, and a few switches to represent future magnetic reed switches located in the door and window.

Using circular buffers, the propeller has several states for monitoring the garage.

  • Not armed — ignore all sensors
  • Armed — system will react to changes in the sensors
  • Exit delay — system has been armed, 45 second countdown has begun to allow you to exit the garage
  • Window trigger — if the window is opened, the alarm will go off immediately (siren and strobe light)
  • Door trigger — alarm will go off in 60 seconds if correct code has not been entered on the keypad

For a complete demonstration, check out the following video where [Ron] explains it all!

Continue reading “Homemade Alarm System Doesn’t Lack Features”

Kindle thermometer

Kindle Gets Downgraded To An Expensive Thermostat

E-readers are awesome, don’t get us wrong — but if you have an old one collecting dust, why not use it for something? [John] decided to hack his old Kindle  to act like a thermometer!

The Kindle’s Linux OS is re-purposed to use the Freescale CPU’s internal temperature sensor as a thermometer — since it’s not doing anything most the time, it should be relatively accurate of the ambient temperature.

Unlike some of [John’s] earlier hacks, this one is completely self-contained and reversible. In fact, it’s just a few scripts that check the temperature every minute and then display it in large digits on the screen. The buttons allow you to convert units or reverse boot to the original Kindle software. It can even graph the recent temperature! It makes for a very easy to read outdoor thermometer.

And not to waste all of its hardware features, [John] also set it up to act as a web server, sending the temperature data via port 8014.

You could also take it a step further and have a full weather station, in a nice wooden frame.

Papilio Duo: FPGA, Logic Analyzer, Debugger, And Arduino Compatible

Back

It’s been a while since we’ve seen some new boards that combine an FPGA and an Arduino, so naturally the state of the art is a little bit behind. The latest from [Jack Gassett], the Papilio Duo, aims to change that by addressing all the complaints of the original Papilio and adding some neat, modern features that you would expect on a board designed in 2014.

On board the Duo is an ATMega32u4, the same chip used in the Arduino Leonardo, allowing for easy integration with your standard Arduino projects. The top of the board is where the real money is. There’s a Spartan 6 FPGA with 9k logic cells, enough to run emulate some of the classic computers of yore, including the famous SID chip, Yamaha YM2149, and the Atari POKEY (!).  With host and device USB, 512k or 2M of SRAM, and an ADC on the FPGA inputs, this board should be able to handle just about everything you would want to throw at it. There’s even a breakout for HDMI on the bottom.

There are a few interesting software features of the Duo, including a full debugger for the ATMega chip, thanks to an emulated Atmel JTAG ICE MKII. Yes, an Arduino-compatible board finally has a real debugger. The FPGA can also implement a 32 channel logic analyzer, making this not only an extremely powerful dev board, but also a useful tool to keep around the workbench.

Talking To ISEE-3

hello.again.m

ISEE-3, the plucky interplanetary spacecraft fueled by the dreams of thousands of crowdfunding backers and hydrazine is now transmitting data to Earth.

Where all radio contact with ISEE-3 this year has only been a carrier frequency, the folks at the reboot project have successfully commanded ISSE via the huge Arecibo telescope to transmit data back to Earth. Usable data are now being received at 512 bits/second at ground stations in Germany, Kentucky, and California, surely being looked over by the ISEE reboot project engineers.

Simply transmitting the commands to put the data multiplexers into their engineering telemetry mode was no small task; a power amplifier needed to be built, shipped to Arecibo, and installed in the giant dome hanging over the Arecibo dish. The amplifier was only installed in the last day, during an earthquake, no less.

There’s still a lot of work to be done before the project can go any further; the team will need to check the status of the spacecraft from the data received, more systems will be checked out, and eventually the spacecraft will be commanded to perform a 17-hour long burn with its small thrusters, putting it on course to be captured by Earth some time in August.

It’s an amazing achievement to do any sort of communication on this scale, and now events in the ISEE-3 mission timeline will be coming rather quickly. We’re trying to organize a video/blog/cast thing with the team from NASA Ames or Morehead State, but the team is, understandably, a little busy right now.

TIQ probe and test box

TIQ Probe Is More Logical Than Most

[youtube=https://www.youtube.com/watch?v=XZz1W-LurlU&w=580]

 

We had [Mark] on our “dance card” for people to find at Maker Faire. But before we could track him down he bumped into us holding the TIQ Probe in one hand and a testing box in the other. TIQ is conceived in the form factor of a traditional logic probe but thanks to the Cypress PSoC 5LP inside it’s much, much smarter than the decades-old bench tools. Sure, it can tell you if that uC pin is a 1 or a 0, but it can also detect what type of signal it’s probing and has built-in protection for over-voltage.

The point of the tool is to bridge the gap between things which would be measured with a DMM and those measured with a proper Oscilloscope. We think he did a pretty good job of including the things that someone just starting out without expensive bench equipment might want. For instance, you can set it to trigger on common data protocols like i2c, and use the probe itself as a rudimentary pulse generator.

The bulk of the details on the probe can be found on its Kickstarter page (which has just a few days left). You may also be interested in his company page. We’re curious about the insides of the test rig he was hauling around. [Mark] is a regular reader so hopefully he’ll leave a comment below with the details of that black box.