by Henry Tonoyan @ htonoyan.blogspot.gr:
Last week I had the idea to create a last-minute valentine’s day gift for my girlfriend. I had a bunch of WS2812 LEDs from my previous endeavors and decided to make a big LED heart. These are a great choice because of the very minimal amount of components necessary: no I/O expanders, driving transistors or ICs necessary. Plus you just need one I/O line from your microcontroller to drive them.
Since they run off 5V, I planned to create a board that is powered from a wall-wart power supply. That way the board doesn’t even need a voltage regulator on it. I chose to use an ATMega48 because I have several from previous projects.
A Valentine’s Day Surprise – [Link]
Gert van Loo, the Broadcom employee responsible for the RPi alpha build has now come up with the Gertduino. He also gave us the GertBoard GPIO Expansion board some time ago which provides general purpose I/Os, LEDs and motor driver capabilities for the Rpi. Gert’s latest creation, the Gertduino board, plugs onto the RPi and connects it to virtually any existing Arduino Shield. The board itself basically offers the same functionality as the Arduino-Uno but with some added features thrown in.
As well as an ATmega328 and ATmega48 (both of which can be programmed from the Raspberry Pi using the Arduino GUI or the GCC Atmel compiler), the Gertduino packs a real time clock, 16MHz oscillator, IRDA interface, RS232 level converter and a battery back-up power supply for the ATmega48.
Gertduino: The Raspberry Pi /Arduino Missing Link – [Link]
Ivan Sergeev writes:
This project was used as a wireless light dimmer, but in principle can be used to dim resistive loads and wirelessly turn on/off loads. The current code includes a routine to dim a light bulb in a “heartbeat” pattern, with the heartbeat frequency remotely adjustable.
The top left of the schematic shows the wall outlet (US 120VAC) being stepped down with a small transformer, then full rectified and regulated. This powers the entire board from the wall. The top right shows a microcontroller, ATmega48, its programming header, and a UART connection to the microcontroller (for debugging). The bottom right shows the XBee and its basic voltage regulation (it’s 3.3V), as well as an LED that indicates when the XBee is connected.
Wireless TRIAC dimmer – [Link]
USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega48 and ATMega88 an ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver, no special USB controller is needed.
- Works under multiple platforms. Linux, Mac OS X and Windows are tested.
- No special controllers or smd components are needed.
- Programming speed is up to 5kBytes/sec.
- SCK option to support targets with low clock speed (< 1,5MHz).
USBasp – USB programmer for Atmel AVR controllers – [Link]
This project shows how to measure the power supply of your micro-controller that can be very important and critical, specially for battery powered applications. The solution the author explains in this short tutorial don’t need any external components, for all the AVR micro controllers that have an internal ADC. As an example in this article, we are going to use an ATMEGA48 micro controller.
AVR: Monitor power supply voltage, for free! – [Link]
This project is a device that accurately measures temperature inside a Styrofoam enclosure and compare it to external temperature. To accomplish this it is utilizing the 8 ADC channels of the ATMega48 and used its in-chip USART capabilities to send this data to a PC for logging.
It’s basically a combination of several projects (microcontroller, temperature measurement with LM335, USART serial port communication, data visualization) for minimal cost. (It’s part of a larger project, but it turned out so nicely that I think it’s a good project in itself!) Many of the temperature sensor pages out there are complicated (using segmented displays or LCD screens), don’t log the data easily, or use expensive components. Also, this project was designed (though not yet tested) to allow 8 sensors to be read simultaneously. Check details on the link below.
Serial Port Multi-Channel Temperature Measurement – [Link]
This project is a temperature controller that controls the temperature of refrigerator and can regulate conditions for food and alcohol fermentations. It is based on ATmega48 microcontroller and includes a remote temperature sensor. It also has a relay to control the refrigerator. Check schematic and source code on the link below.
YATC – Yet Another Temperature Controller – [Link]
ikalogic.com just finished IKA-TACH project which is a contactless Tachometer based on ATMEGA48 AVR micro controller. Detection of rotation is done using a IR transmitter / receiver module. There is also a red led that helps point the invisible IR led. This tachometer is able to measure both low RPM speed and high RPM speed. Check construction details and KIT on the link below.
IKA-TACH: DIY Contactless Tachometer – [Link]
This is versatile development board for AVR microcontrollers ATmega48/88/168. It is good for testing and debugging embedded programs. It has many built-in peripheries connected to microcontroller so you can use them without soldering. ATmega microcontrollers are produced by ATMEL and they include a lot of features: I/O, Timers, PWM generators, ADC, RS232, TWI, SPI, Analog Comparator, Oscillator, EEPROM These microcontrollers are very versatile, easy to program and easy to use. This is the reason why I like these microcontrollers and why I decided to make development board for them.
ATmega48/88/168 Development Board – [Link]