As of Arduino 1.0, interrupts are not supported on the Arduino Leonardo. I’m working on a project using the atmega32u4 with the Arduino IDE which needs interrupt support for both software serial and frequency counting, so I investigated ways to add interrupt support for this device. I began by checking out the Leonardo pins definition file to see what was missing for interrupt support. Long story short, I ended up copying the macros for interrupt bitmasks/registers from the Teensyduino project, which has a mega32u4 target board. In addition to modifying the pin definition header file, I also needed to modify WInterrupts.c—swapping out the default AttachInterrupt() and DetachInterrupt() funcitons with those from the Teensyduino project.

I have included links below to the pin definition header file and interrupt functions in my project repository. Place these files in the hardware/arduino/core and hardware/arduino/variants/leonardo folders. Note that my current revision of these files only support the m32u4, interrupt support for other devices is broken. You can throw some #ifdefs in there and include the existing code to support devices other than the m32u4, I will hopefully get around to adding this in the coming weeks.

I also want to get SoftwareSerial up and running on the m32u4; I’ll be looking into the Teensyduino variant of NewSoftSerial this week, check back for more updates in the coming days.

Downloads

• WInterrupts.c
• pins_arduino.h

This project uses the open-source i2c RGB LED controller firmware “cyz_rgb” to create a modular high-power lighting network. The network is controlled by an Arduino, which scans the network for nodes controls them autonomously with onboard scripts, manually via serial console control, or over the serial computer-control interface for interaction with programs on a host machine.

Node: BlinkM Clone

Hardware

Each node consists of only a few inexpensive components. The total cost of each node, not including shipping or bulk discounts, is around $5.50. If you order more than 3 of the 3W LEDs, the price drops drastically ($2.74 per LED and lower.

• ATTINY85 - $1.82 – Cheap, small footprint, plenty of memory.
• 3W RGB LED from DealExtreme – $3.35
• NPN Darlington transistors (only $.04 from Mouser!)
• 10uF decoupling capacitor
• Current-limiting resistors for each LED (must be 2W+ rated!)
• Optional: Pin header, screw terminal, reset switch

Initial Prototype on protoboard (resistors have been upgraded to 2W in the final boards)

The initial prototype node boards are shown below. These nodes include non-standard programming headers, screw-terminal power connectors, and incredibly under-rated resistors (1/4 watt for the red LED resistor!). 2W+ rated resistors are necessary if you are using a 3W+ LED. I would also recommend adding terminals for the clock and data lines, unless you want to run ribbon cable between the ICSP headers of each board which, conveniently enough, breaks out the needed power and data lines.

Controller: MNLC

The controller for the network of i2c-connected nodes is an Arduino running MNLC. This sketch provides a simple serial terminal for manually communicating with the network of nodes, and also provides a non-interactive serial mode for host computer control. Included for testing is some code from jarv.org which reads an analog audio signal and cycles the network of LEDs through various patterns based on the amplitude of the incoming signal.

Fully assembled prototype board with proper resistors

Build your own:

1. Assemble node(s) as shown in schematic above
2. Connect programmer to each node and flash ATTINY85 chips with cyz_rgb_slave firmware
3. Unset the divide clock by 8 (DIV8) fuse on each node
4. Assemble audio input circuit (if needed) and flash Arduino with MNLC
5. One at a time, connect each node to the Arduino
6. Once the node is connected, enter the interactive serial interface and use the “i” command to set a unique address for each node.
7. Daisy-chain clock and data lines of all nodes to the Arduino, add pull-up resistors on both the data and clock line, and run MNLC sketch

Additional information on the construction of the final design and some notes about scaling this project up to a 12-node network with considerable distance between nodes will be added in the near future.

Well, the school year is over, so I thought I’d post up some information about my (extremely cheap and junky-looking but functional) door opener.

The door handle is turned by one 24v globe motor (which have encoders that I’m sadly not using at the moment), and is pulled open by another identical motor. A very affordable ($30) SparkFun RFID reader is attached to the back the door so cards can be scanned from the outside. An arduino controls the process, and drives motors and a cooling fan with 3 darlington transistors.

Power supply case housing arduino and circuitry, along with door-pulling motor and ridiculously ugly tie-dye duct tape

The arduino was attached to an old Dell laptop, which ran the Apache webserver. A small password-protected php web interface was created to allow door opening from anywhere on campus. KDE4 widgets allowed door opening from computers inside the room, letting my roommate and I avoid walking less than 8 feet (or less) away to open the door for someone.

Touchscreen mounted to wall, password widget not shown. And no, I did not actually go to school in Munich, Germany

I also put a password-protected KDE4 widget on our touchscreen mounted on the wall outside of our room, so if one of us forgot our RFID card, we could type in a password on the touchscreen, and the door would open. Fun stuff.

Unfortunately I don’t have too many pictures, and the entire thing is disassembled now. Hopefully next year I’ll improve it (encoders and PID for motion control?) and post some more information.

Many DIY projects that people attempt these days include internet connectivity, logging, gps tracking, sensor data storage, and remote control. People have used xBee, GPS modules, and extra hardware to integrate all of these features, but there is a much simpler way–using an iDen pay-as-you-go phone.

Older iDen models (check out eBay) have serial ports on them, which can be used for computer interfacing and for Arduino connectivity. USB models cannot interface with an arduino, so go for a serial version. You will also need a serial cable for the phone. If you’re cheap, you can solder up some wires directly to the phone, as the cable is usually a bit pricey. Break out your needle-tip iron and get to work!

The best feature of the phone, perhaps, is internet connectivity. Load any browser or j2me app on it via the serial cable, and you instantly have internet access. And it’s free. Don’t activate the “mobile internet” option that costs 20c per day, that merely unlocks the WAP browser. J2ME apps can access the internet without any subscription, which opens the door to many features.

One of the easiest features to use is GPS tracking (great for weather balloons!). Just load up mologogo on the phone, and you instantly have a web-viewable GPS tracker. You can also attach an external antenna to the phone for added reception in shielded environments (peel up the black sticker near the battery compartment to reveal the connector).

An added benefit of the phone is simultaneous java application running. You can be running mologogo for GPS tracking while running your own custom app for arduino interfacing. Speaking of app creation for arduino interfacing, check out Mobile Processing. Mobile processing will allow you to create processing sketches that can run on your iDen phone, allowing you to interface with the internet and the arduino via serial. Check out five.b.oh, a great resource for connecting your phone with your Arduino via Mobile Processing.

Have any projects or ideas using an iDen phone and an AVR/arduino? Drop us some comments. If you have an interesting project, we might just feature it on the site.

Note: A boost mobile iDen phone can be had for 10-30 bucks, depending on where you get it (ebay, or a retailer). These phones come with $10 of free minutes, and 30 days of activation, so for a short-term project, additional minute-purchasing won’t be needed. For continuous use, the phone can be kept activated by adding $10 to it every 3 months, which works out to $3.33 per month.

This project is extremely basic (and exceptionally cheap), and has an overkill motor for rotation. Also, tilt support was never implemented. However, it does make use of the remote shutter support of the CHDK firmware for Canon cameras to allow arduino-triggered photos.

Drop some comments below if you have done something similar, or if you have used any code/ideas from my design.

What The Current Code Does:

• Takes a photo via usb pulse sequence
• Rotates X degrees
• Takes a photo via usb pulse sequence
• ^REPEAT^
• When it goes 360 degrees, it rotates 360 degrees in the opposite direction
  • Keeps the camera cable from wrapping around the base
• Operation pauses, waits for user input
  • At this time, the user tilts the camera to a different angle
  • After tilting, the user presses the button on pin 10
• The camera begins this sequence again

Features

• 360 Degree rotation
• .9 Degree Accuracy per shot
• Programmable Delay
• USB Shutter Control
• Portable

Parts

• Arduino Microcontroller
• Stepper Motor (1.9 Degree step or less recommended)
• Some sort of battery for standalone operation
• A Supported Camera
• A tripod (old all-metal tripods with bolt interconnects are best)
• Bolts and nuts to fit your motor and tripod
• Scrap wood or sheet metal (Sheet metal recommended for camera arm)
• Set Screw and metal tube to fit around motor shaft (or use whatever you have lying around)

Supports

• Canon S* IS Series
• All other cameras that support CHDK

Sample Panorama

Resources:

• PanoBot Code