Observe A Satellite’s Morse Code Message Today!

December 12, 2012 by 58 Comments

Niwaka1-satellite

If you live in the Eastern portion of the United States and the skies are clear you can see a student built satellite flashing LEDs in Morse Code today. But don’t worry. If you it’s cloudy or if you live elsewhere there are several other opportunities to see it in the coming days.

This is the Niwaka Fitsat-1. It was developed by students at the [Fukuoka Institute of Technology] and deployed from the International Space Station on October 4th. Included in the payload is an array of LEDs seen in the image above. On a set schedule these are used to flash a Morse Code message for two minutes at a time. That is what’s shown in the image on the upper right.

You can look up information on seeing Fitsat-1 in your own area using this webpage. All of the observation windows in our area require a pair of binoculars or better. We’re not sure if there is any case in which this can be seen by the naked eye.

[Thanks SWHarden and KomradBob]

Making Your Anime Papercraft Move To The Music

September 25, 2012 by 15 Comments

This anime character is dancing to the music thanks to some animatronic tricks which [Scott Harden] put together. She dances perfectly, exhibiting different arm and head movements at just the right time. The secret to the synchronization is actually in the right channel of the audio being played.

The character in question is from an Internet meme called the Leekspin song. [Scott] reproduced it on some foam board, adding a servo to one arm to do the leek spinning, and another to move the head. These are both driven by an ATtiny44. All of the movements have been preprogrammed to go along with the audio track. But he needed a way to synchronize the beginning of each action set. The solution was to re-encode the audio with one track devoted to a set of sine wave pulses. The right audio channel feeds to the AVR chip via an LM741 opamp. Each sine wave triggers the AVR to execute the next dance move in the sequence. You can see the demo video for the project after the break.

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Multi-channel Analog Input Module Is A Good Jumping-off Point For Many Projects

June 19, 2012 by 12 Comments

[Scott Harden] has already produced some projects which measure analog inputs. But he’s got plans for more and wanted a base system for graphing analog signals. You can see the small board next to his laptop which offers the ability to sample up to six signals and push them to a PC via USB.

The ATmega48 and a few supporting components are all you’ll find on that board. The USB connection is taken care of by an FTDI cable. He went that route because the cables are relatively cheap, easy to come by, and already have driver support on all the major operating systems. If you look at the screen you can see a window graphing one analog input in real-time. He wrote this in Python (which is once again a cross-platform tool) and it has no problem graphing all six inputs at once.

This is immediately useful as an upgrade to [Scott’s] ECG machine. His future plans include a Pulse Oximeter, EEG, and EEG.

[Scott] Made A Single-chip Hellschreiber On Earth

August 8, 2011 by 38 Comments

[Scott Harden] is drilling teeth by day and designing radios that send secret messages by night. He’s set his sights on the Hellschreiber protocol which was used by the Germans in World War II along with their Enigma encryption system. The protocol is a viable alternative for transmitting and receiving code in environments with too much background noise for other communication systems.

His goal was to develop his own transmitter using just one microcontroller. He picked an ATmega48 and coupled it with a 40 MHz crystal oscillator. [Scott] mentions that there is no other hardware necessary, but static messages stored in an array so you’d need some other hardware to push your own characters through via the chip’s UART or otherwise. The AVR sends messages by converting the data into audio using PWM. That signal is fed into the crystal oscillator, which produces an amplitude modulated signal (AM) that can then be transmitted.

Check out his video after the break for a demonstration. He’s decoding the transmitted data using a free program called Ham Radio Deluxe.

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Microcontroller Communications Using Flashing Lights

July 28, 2011 by 43 Comments

phototransistor_pc_microcontroller_communications

[Scott] was driving in the pouring rain behind a car with its blinkers on when inspiration struck. He had previously created a simple communications system using his sound card that allowed him to send data to a microcontroller from his PC, but he thought that doing the same thing with light would be an interesting exercise.

He decided that the best way to go about building such a system would be to use a phototransistor along with his computer monitor to send data to his microcontroller. While he couldn’t really think of any practical application for the project, that didn’t stop him from putting it together just for grins.

[Scott] says the circuit is dead-simple, and includes a pair of phototransistors along with their required resistors. The receiver was tied into the ADC of his microcontroller, where he was easily able to pick up some simple light patterns. His ultimate goal is to put together a javascript application that sends data to his microcontroller, though he’s looking for a bit of assistance on the programming side of things – any takers?

While [Scott] couldn’t come up with any applications off the top of his head, we know of at least one. Anyone familiar with the Bloomberg financial application will likely have come across their “B-Unit”. This piece of hardware is about the size of a credit card, but thicker. Armed with a fingerprint scanner and a photodiode, it reads a series of flashing lights from your computer screen in order to ‘synchronize’ the unit for each login session that is not initiated with an official Bloomberg keyboard. So there’s one for you!

Continue reading to see a video of the system in action.

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Adding USB Connectivity To Old Benchtop Tools

July 25, 2011 by 7 Comments

frequency_counter_hacked_for_usb_connectivity

[Scott] was recently given a frequency counter, and once he brought it home, he started contemplating how he could possibly make it better. While the counter worked well as-is, he wanted to find a way to record data readings over a reasonably long period of time. He figured that interfacing it with his computer would be the best way to do this, but he had to find a way to connect the devices first.

He started poking around inside the frequency counter and stumbled upon a possible data source when taking a closer look at the display board. He found that he could read the frequency data as it was being written to the display, and send that data to his computer. He used an ATMega48 to intercept the data and code from the V-USB project to bit-bang the data to his PC over USB.

Now, anything he sees on the frequency counter can be easily collected and graphed on his computer with little fuss.

Stick around to see a quick video demonstration of his hack in action.

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Sound Card Microcontroller/PC Communication

July 10, 2011 by 40 Comments

The usual way send data from a microcontroller is either over RS-232 with MAX232 serial ICs, crystals, and a relatively ancient computer, or by bit-banging the USB protocol and worrying about driver issues. Not content with these solutions, [Scott] came up with sound card μC/PC communication that doesn’t require any extra components.

[Scott] bought a cheap USB sound card dongle on eBay (although a built-in sound card will do) and wired up the tip and ring of the plug to the microcontroller. The data is sent from the microcontroller a lot like Morse code – a short gap between pulses is a zero, a long gap is a one. This is parsed by a Python script using PyAudio. Synchronization, timing, and calibration is automatic because of a 10-bit ‘packet header’ explained in this video.

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