code and fabrication resources for physical computing and networking
D.Tools is Stanford Design School’s entry into the microcontroller module market. D-tools is based on the Atmel microcontrollers, like Wiring and Arduino. Also like those modules, it’s based on Pascal Stang’s AVR C libraries for the Atmel micros.
Technorati Tags: arduino, d.tools, electronics, open source, pcomp, physical computing
EZIO is a PIC based module that can read sensors, write to outputs, and send PWM signals to its outputs, all with simple serial commands.
Technorati Tags: electronics, PIC
Dan Mikesell sent this link to a site explaining how to make your own organic LEDs (OLEDs). Assuming you’ve got access to a chemistry lab, it seems very possible. I’d be interested to know how noxious the chemicals are, though. We were both wondering what happens when you start making OLEDS in different shapes, and on different surfaces, like fabric, plastic, metal, etc.
Technorati Tags: chemistry, electronics
Sometimes you want to send a binary value into Processing (say, from a microcontroller) and check the individual bits of the value. This example checks the bits of an 8-bit number individually, and reports whether each one is a 0 or a 1.
So we tried a few experiments in toaster oven soldering this weekend, and had limited success. In the end, it was easier to do the job with a soldering iron, because our surface mount chips were fairly big. But here’s a few tutorials on others’ attempts at it:
Sparkfun has a number of good methods, using a skillet and using a toaster oven.They also have a good tutorial on solder paste stenciling.
Seattle Robotics has a nice clear tutorial on toaster oven reflow.
Thanks to Raffi Krikorian for the link.
Raffi’s notes on his experiment at ITP, on how to get the timing right for reflowing a part already soldered to the board: “we put a piece of solder in there too (on a piece of tin foil), and the instant that solder melted, i pull the board and just tapped it — the IC fell right off…”
Here’s another toaster-oven soldering example, thanks to Sasha Harris-Cronin for the link.
Technorati Tags: electronics, PCB
This program controls a stepper motor from an analog input. In testing it, I used a potentiometer, which gives a persistent value. An analog input that changes when it’s not contacted, like a SpectraSymbol linear or circular pot, wouldn’t work with this example.
Thanks to the Fall ’05 Wednesday morning class for the early experimentation on this code.
Written in PicBasic Pro, tested on a PIC18F252
Continue reading “Stepper motor controller from analog input”
This program connects a microcontroller to a mySQL database via a Lantronix Xport and a PHP script.
The PHP script it uses is the SQL_datalog.php script in the Network Data Logging Suite.
Technorati Tags: networked objects, networks
This suite of programs takes data from a sensor and saves it to a text file on a network. Each sensor reading is time stamped. The suite illustrates the basic principles involved in sending sensor data to a networked file or database.
The first program involved is a microcontroller program, written in PicBasic Pro, tested on a PIC18F258. It waits for serial input from an external program. Then it reads its analog sensor, and sends the result out in two bytes.
The second program is the same microcontroller code in Wiring/Arduino, thanks to Jamie Allen for the cleanup.
The third program involved is a desktop computer program, written in Processing. It requests data via its serial port from the microprocessor and sends that data to a CGI program on a web server. It passes the data into the CGI using an HTTP GET request. This program only sends every three seconds, so as not to overwhelm the server with hits.
The fourth program is a CGI (common gareway interface) program, written in PHP. It takes in data from an HTTP GET request and appends it to a text file, along with the time the request was received. Note that this program does not check to see how big the file is, or whether the incoming data is properly formatted, so it isn’t terribly secure.
The fifth program is another PHP script that logs the data to a mySQL database. Running this doesn’t require any change in the microcontroller code, but it does require a slight change in the Processing code. The change is in the sentToNet() method, and is noted below.
Technorati Tags: networked objects, networks
This program takes input from a Sharp GP2D120 infrared ranging sensor and outputs the result in ASCII. The ranging formula comes from an excellent article on Acroname’s site, tweaked a bit to work with my circuit.
Continue reading “Linearizing Code for Sharp GP2D120 Infrared Ranger”
Here’s how to find the average of 9 samples, or the median number of a sorted list of samples. Arduino/Wiring and PicBasic Pro examples follow.
Thanks to Zach Layton for correcting my bubble sort code and Zach Lieberman for the correction.