Today we’re releasing an update to our “Peggy” open-source LED Pegboard project. Peggy version 2 has been redesigned from the ground up. And it looks… almost exactly the same. The changes under the hood are substantial, though, and we think that it’s a big improvement in many ways.
First and foremost, Peggy 2.0 still does the same darn thing: it provides efficient power to a 25 x 25 array of LED locations. Peggy is designed to take some of the sting, complexity, and mess out of playing with LEDs. It’s a versatile and powerful light-emitting pegboard that lets you efficiently drive hundreds of LEDs in whatever configuration you like, without so much as calculating a single load resistor. You can install anywhere from one to 625 LEDs, and Peggy will light them up for you.
Peggy can optionally be reprogrammed to do much more, of course. The biggest change is that the Peggy 2.0 hardware now supports simple animation capability with individually addressable LED locations. Besides the microcontroller, there are now four support chips that help to drive the rows and columns of the display. Now, we’re not talking live video feeds or long movies here (speed and memory considerations will spoil that party), but you might be surprised how much you can do with a little AVR microcontroller.
The second improvement has to do with the programming interfaces. As before, Peggy supports programming through a regular AVR ISP (in-system programming) connection, such as the USBtinyISP. However Peggy 2.0 is now also Arduino compatible: it supports programming through a USB-TTL cable, using the popular Arduino software environment. (This is the same programming arrangement that you’ll find on some of the popular Arduino-compatible boards such as the Boarduino and Bare Bones Boards.)
Other improvements and new features:
- The size of the circuit board has been slightly tweaked to 11.320 X 14.87″. The new narrower width allows multiple Peggy 2.0 boards that are lined up side by side to form an uninterrupted LED field.
- A small breadboard-style prototyping area
- 16 MHz crystal oscillator for improved timing and communications
- Extra space to add up to five optional tactile buttons including four “arrow” keys. Could come in handy if you are using Peggy as a game platform.
- Peggy 2.0 now uses the popular ATmega168-20PU microcontroller. An awful lot of existing Arduino code can run on it without modification.
- Full-size power slider switch now standard equipment.
- Still fully open source and designed to be hacked. Schematics, code, and extra access points are provided.
Here are some project ideas that might be fun to try with Peggy 2.0:
- Boring old static LED sign.
- LED clock with digits. BIG digits.
- Scrolling readerboard.
- Low-speed oscilloscope.
- FFT sound grapher.
- Mega MiniPOV!
- Add a temperature sensor in the prototyping area and make a giant display thermometer.
- Add a EEPROM in the prototyping area to store data for a long animation.
- Variable color LED panel, fading between different color LEDs in different areas.
- 14×14 RGB display, clumping three LED locations to form an RGB pixel.
- RSS reader?
- Mega-emoticon display for use in car
- Simulated animated neon sign.
- Open/closed sign that states your hours, too.
- True sprite animation
- Simple video games!
- LED status board.
- Blinkylight array for your sci-fi movie computer set.
Since the full display is addressable, there’s really a wide-open set of potential applications. As a first demonstration I wrote a version of Conway’s game of Life. It’s not written from scratch; it’s adapted from this project by David Gustafik, and the code is available under the GPL. We’re embedding a little YouTube video here; if you can’t see it, you can click through to YouTube.
How do you make it?
This project is fully documented, open source, hacker friendly, and you can approach it from any direction you want. Start with the schematics and code, or start with a circuit board and a soldering iron. It’s all yours:
- Get a kit here.
- Build instructions, schematics, and bill of materials are all wrapped up in one big PDF here (10 MB PDF File)
- Learn about programming Peggy 2.0 in a separate article here.
- The circuit board was designed in gEDA PCB, and you can download the original PCB file here; Fundamentally, it’s also source code; we are releasing it under the GPL.
- Want to talk about it? That’s what the forums are for.
1. What’s this all about?
This is an easy way to drive a lot of LEDs– up to 625– in a big matrix. You can make an LED sign for your window, a geeky valentine for your sweetie, one bad-ass birthday card, or freak the holy bejesus out of Boston. Your call. It’s a versatile, high-brightness display.
The display can run off an AC adapter or batteries (3 ‘D’ cells), and is designed to run as LEDs as you care to solder into the holes, all with excellent brightness. The board can accommodate LEDs in several common sizes: 3mm, 5 mm (standard T-1 3/4 size), and 10 mm.
2. Do I have to put the LEDs on the grid, or can I position them exactly where I want to?
You do not have to place every LED on a regular grid. See the instructions for some tips on how to position the LEDs more arbitrarily.
3. Do the LEDs get soldered in the holes?
If you do want to add sockets, go right ahead. (Peggy is designed to be hacked.) However, keep in mind that you’ll probably end up doing more soldering in total, and those sockets cost more than you might think.
4. Does the Arduino Bootloader come preinstalled on chips in the kits? Does it work? Is this the world’s biggest Arduino?
Yes, yes, and no.
Use a USB-TTL cable and tell the Arduino software that you have a Diecimila. It works well. While the board is big, it is technically not “an Arduino”, as per
guidelines issued by the Arduino team. (Arduino is the proper name of a hardware + software platform, so the term “an Arduino” is a bit misleading in any case.) Peggy 2.0 is merely open-source hardware that happens to be compatible with the Arduino software development environment. (And no, we won’t rename it Pegguino.)
5. What is the default program installed on the chips in the kits?
First, we load the Arduino bootloader onto the chips, and then we load up the default program, which lights up every LED location on the board. That way the board will work correctly if you just start using it, but it will also accept reprogramming through the Arduino environment, or (as always) accept programming with an AVR-ISP programmer.
6. Is “Peggy” named after someone?
Nope. It just comes from the term “pegboard.”
7. What does Peggy 1.0 have that Peggy 2.0 doesn’t?
- Light sensor (you can still add one if you want to, of course)
- Gold-plated circuit board finish (new finish is lead-free solder)
- Board size that’s an integer number of square inches