Software Pulse Width Modulation

September 17, 2009 by Mike Szczys 11 Comments

daqq_pwm_schematic

Pulse Width Modulation is a topic that tends to give a lot of beginners trouble. [Daqq], whose nixie plasma ball we covered a few days ago, has a simple but effective PWM project that you should take a look at. The circuit used 9 LEDs clustered together into 3 sets of RGB modules and connected them to an AVR ATtiny2313 through some current limiting resistors. Most of the time the PWM function of the AVR’s timers would be used to generate the signal but this application calls for 9 signals which is more than can be produced by this chip. The workaround is to generate the signals using software PWM. Continue reading “Software Pulse Width Modulation” →

Serial Hacking With An ATtiny2313

August 6, 2009 by Steve Watkins 19 Comments

board

[Sprite_tm] automated a portion of serial hacking by sniffing out the baud rate using an ATtiny2313 and FT232 breakout board. The firmware assumes 8 data bits, no parity, and 1 stop bit (8N1). This is pretty much defacto among serial ports so it should work well, though some devices do use different settings. The auto detection routine can sniff rates as low as 110 baud and supports non standard rates. Released under GPLv3, the software is also supplied in hex format. [Sprite_tm] has provided great project in past such as Working with VFDs, Controllable bristlebot, and AVR boost converter. Additional information regarding serial hacking after the break.

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Business Cards At Maker Faire

May 30, 2009 by Eliot 9 Comments

business_card

[John Park] has managed to snag a couple interesting business cards at Maker Faire. The first is Adafruit’s laser cut Spirograph card. The other is a ATtiny2313 prototyping board from Evil Mad Science; it looks to be the same style as their well-known AVR target board. We’ve also heard rumors that [Jérôme Demers] has bunch of resistor bending cards.

For more business card nonsense, check out: [Goodspeed]’s smart card emulator, [Mayer]’s embedded gears, and our web server business card.

64pixels Are Enough

March 21, 2009 by Eliot 7 Comments

64pixel

[Alex] put together this lovely minimal LED project. The square pixel matrix is soldered directly to the microcontroller in the same style as EMSL’s Micro-Readerboard. During the prototyping phase he used resistors to limit the current from the programming board. The final product doesn’t use resistors and manages the current draw by only turning on a single pixel line at a time. The illustrated assembly guide is very thorough and should help your create an equally compact device. Check out a video of it in motion below.

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ATtiny Breadboard Headers

January 18, 2009 by Eliot 22 Comments

attiny

[Alex] was frustrated by the amount of time it took to start prototyping with an AVR ATtiny. To make things easier, he built headers that carry the 8 and 20 pin chips and plug directly into breadboards. The boards include a 6pin ISP header, resonator, pull-up resistor, reset, and blocking caps. The ATtiny2313 version also has a serial connection header. This is a prototype though, and he forgot to route one of the connections. He plans on having a large batch of boards ready for next month.