Jeri builds a 52 inch Etch A Sketch from a HD projection TV, tent poles, golf tee and gear reduced motors. Net enabled through Monty’s Ustream chat (IRC) robot control. Hours of fascinating fun for the entire internet!
Here’s our photo set from the Spring 2009 ITP show… and (above) a video (m4v & HD) of some of the projects – this year augmented reality started to appear in the student projects and we also saw a lot of Processing / camera projects. It’s always hard to just pick one favorite project – so we picked two.
CRUDLABSSteven Litt…The culmination of my work at ITP building CrudBox, an electroacoustic/electromechanical step sequencer, and the open-sourcing of the entire project. CrudLabs is an organization dedicated to new research into combining traditional electronic music interfaces with methods of electroacoustic and electromechanical sound creation in new and unexplored contexts. It’s first major endeavor is the fabrication and open sourcing of CrudBox, a 16 step, 8 channel step sequencer which replaces digitally created or analog synthesized sounds typically associated with sequencers and electronic music with the amplified sounds of whatever electronic or electromechanical devices are plugged into it.
Firefly 870 LED Prototype – A wind responsive LED screen – Jason Krugman… Firefly 870 LED Protoype pairs 870 wind switches with 870 super-bright white LEDs to form an 8′ x 8′ grid. As the wind blows over the piece, the wind switches trigger each LED individually, creating a stunning sparking effect in response to the wind. If every LED were to turn on, the entire piece would consume as much electricity as a single 60-Watt light bulb.
And… Something new this year… a few projects had “patent pending” as part of the artist statement.
Diffused RGB (tri-color) LED – Diffused 5mm tri-color LED with red, green and blue inside! Nice indicator, and fun to color-swirl. 80 degree viewing angle. Red LED Vf = 2.1V, Green LED Vf = 3.3V, Blue LED Vf = 3.3V. About 1000 millicd. per LED output brightness (no datasheet, sorry!) To use, connect the longest lead to Vcc/power, and then connect the other three remaining leads to ground (or your microcontroller pins) through a proper series resistor. If you’re using 5V, we suggest going with 150 ohm for red, and 82 ohms for green and blue for max brightness. Higher valued resistors for less brightness.
IR sensor – IR sensor tuned to 38KHz, perfect for receiving commands from a TV remote control. Runs at 5V (although it seems to be OK down to 3.3V) To use, connect pin 3 (all the way to the right) to 5V power, pin 2 (middle) to ground and listen on pin 1. It doesn’t do any decoding of the signal, just passes the ‘raw data’ along. Check out the datahseet!
Hall effect sensor – Hall effect sensors detect whether a magnet is near. Useful for non-contact/waterproof type switches, position sensors, rotary/shaft encoders. This sensor is used in the SpokePOV kit to determine when the wheel has made a revolution. Runs at 3.5V up to 24V. To use connect power to pin 1 (all the way to the left), ground to pin 2 (middle) and then a 10K pull up resistor from pin 3 to power. Then listen on pin 3, when the south pole of a magnet is near the front of the sensor, pin 3 will go down to 0V. Otherwise it will stay at whatever the pullup resistor is connected to. Nothing occurs if a magnet’s north pole is nearby (unipolar). Works fantastic with the high strength magnetRead the datasheet. Read a nice whitepaper from the manufacturer with many ideas and designs for use
It uses LDRs to measure the gray-scale of specific point of a image, and triggers midi notes from a selected threshold. When the threshold is reached the velocity will be set by the darkness at that point. the darker point the higher the velocity will be.
The sequencer plays the notes as a arpeggiator, i chose for this playback method because i dont have a midi device that can play 24 keys at the same time.. There are 2 different arpeggio modes. One rearranges the playback sequence to the active notes velocitys. And the second mode changes the arpeggio playback speed to the amount of notes that are active. If this mode is not selected the playback speed is set by a potentiometer. These modes can also be combined.
The sequencer has 24 LDRs that are read into 3 ADC ports of the arduino, via 3 4051 ics.
Corrin and I dropped some stuff off at Goodwill the other day, and when we were looking around inside I made an amazing find. For only two dollars, I purchased a pop-up book describing the internals of a 1980’s PC! I’ve uploaded pictures of most of the book. I left out a few of the more boring features, such as opening a floppy disk to see the mylar disc inside.
It’s Friday night at Adafruit, usually that means we take apart something… Here’s part I of reverse engineering a pager (m4v).
NOTE: Oops, I was tired. There’s a mistake in the video! The chip is a TA31149 4-FSK (not 31142 2-FSK), and I printed out the wrong datasheet. Still, its pretty much the same idea/chip, just follow the ’31149 datasheet for the correct pinouts, there are -two- serial lines for 2 bits of serial data. Sorry about that!
The bootsector of DOS 1.0 is celebtaring its 28th birthday today (it contains the timestamp “7-May-81″), so let’s look at it more closely.
DOS 1.0 shipped on a 160 KB single sided disk. The boot code in the IBM PC’s BIOS loaded the first sector into RAM at segment 0×0000, offset 0×7C00 and ran it. Later versions of BIOS checked for 0xAA55 in the last word of the bootsector, but the first version did not. Note that DOS 1.0 is also pre-BIOS Parameter Block, i.e. the bootsector does not contain any information about the physical layout of the disk, since there was only a single disk size.
What the boot sector is supposed to do is read “IBMBIO.COM” and “IBMDOS.COM” into RAM and run them – these are the DOS system files for machine abstraction and DOS API, respectively. In MS-DOS, they would be called “IO.SYS” and “MSDOS.SYS”.
But the DOS 1.0 bootsector takes quite a lot of shortcuts. It assumes it’s always a 40 track, 8 sectors single-sided disk and the two files occupy the first sectors of the data area contiguously – something that SYS.COM could guarantee when making a disk bootable.
So the bootsector first loads the first sector of the root directory (hardcoded to track 0, sector 4) and compares the first two entries with “IBMBIO.COM” and “IBMDOS.COM”. For some reason, the comparison is case-insensitive, although DOS only allows uppercase filenames.
Continuous rotation servos and standard servos are now in stock!
Continuous Rotation Servo… This servo rotates fully forward or backwards instead of moving to a position. You can use any servo code, hardware or library to control these servos. Good for making simple moving robots. Comes with one horn only, as shown
Power 6vdc max (5V works best)
Average Speed 60 rpm (Note: with 5vdc and no torque)
Weight 45.0 grams/1.59oz
Torque 3.40 kg-cm/47oz-in
Size mm (L x W x H) 40.5×20.0×38.0
Size in (L x W x H) 1.60x.79×1.50
To control with an Arduino, we suggest connecting the white control wire to pin 9 or 10 and using the Servo library included with the Arduino IDE (see here for an example sketch). Position “0″ (1.5ms pulse) is stop, “90″ (2ms pulse) is full speed forward, “-90″ (1ms pulse) is full speed backwards. They may require some simple calibration, simply tell the servo to ‘stop’ and then gently adjust the potentiometer in the recessed hole with a small screwdriver until the servo stops moving.
For more information, check out the Parallax Datasheet. Grab one at the Adafruit store.
Standard servo – This standard servo can rotate approximately 180 degrees (90 in each direction). You can use any servo code, hardware or library to control these servos. Good for beginners who want to make stuff move without building a motor controller with feedback & gear box. Comes with 3 horns, as shown. They aren’t the highest quality servo (which is why they are less expensive) and so are not suggested for hobby planes
Power 6vdc max (5V works best)
Average Speed 0.23 sec/ 60° (Note: with 5vdc and no torque)
Weight 39.2g (1.37 oz)
Torque @ 5V 3.20 kg-cm/45oz-in
Size mm (L x W x H) 40.6 x 20.0 x 38.9 mm
Size in (L x W x H) 1.60x.79×1.50
To control with an Arduino, we suggest connecting the orange control wire to pin 9 or 10 and using the Servo library included with the Arduino IDE (see here for an example sketch). Position “0″ (1.5ms pulse) is middle, “90″ (2ms pulse) is all the way to the right, “-90″ (1ms pulse) is all the way to the left. In the Adafruit store.
You asked for them, now they’re here! The breadboarding wire bundle that we include in the Arduino starter pack are now available seperately! The breadboarding wire bundle is a pack of 75 flexible stranded core wires with stiff ends molded on in red, orange, yellow, green, blue, brown, black and white. These are a major improvement over the “box of bent wires” that are sometimes sold with breadboards, and faster than stripping your own solid core wires. Makes breadboarding super fast. Available now in the Adafruit store.