The ARDF controller was created after a request to be able to play random audiofiles for an ARDF transmitter, most existing designs were based on an 16F84, a somewhat aging design and better controllers are currently available. Also most controllers had a 5-10 mA current drain which can be improved, this design requires less than 400 uA.
To allow a very small controller footprint and flexible configuration the timer is not configured with (dip) switches but via a serial connection and a host PC. The memory option is optional and is only required for a wave file playback, all other options (CW, Single Tone, Tone Sequences and Audio Effects) do not require the I2C memory chip.
ARDF Timer / Controller: [Link]
In many microcontroller applications some sort of display is needed to present information and status of the controller to the user. Although a few LEDs can provide a lot of information, a more advanced display is sometimes needed. A solution which is quite often seen is using a HD44780-based character LCD module. These modules come in various configurations from one line of 8 chars to 4 lines of 40 characters.
Implement HD44780-based LCDs With AVR Microcontrollers: [Link] - [via]
The MAX6953 from Dallas Maxim is a compact cathode-row display driver that interfaces a microprocessor (like PIC or AVR) to four 5×7 dot matrix LED display trough an I2C compatible serial interface. The Max chip includes some nice features like:
- low-power shutdown mode
- segment blinking
- test mode that forces all LEDs on
- 16-Step digital brightness control
This project can be considered both a led matrix controller and a development board for MAX6953. The project presents only the max6953 and the led matrix, if you want it to display anything, you’ll also need to stick a microcontroller in there and write some code. You might want to check this other article 50×7 LED Matrix which has everything included.
MAX6953 LED Matrix or development board: [Link]
LEDLoad is a device and software designed to controll two LED’s from your computer case. It uses modern tri-color LED’s that change color according to the computer processor load. So the only modification you need to make is to replace the original case LED’s with the tri-color ones. The device shows Blue for idle and gradients light blue, green, yellow, orange, and finally red indicating high CPU load. If the circuit loses communication with the software it flashes RED thus letting you know that the system has crashed or there is something wrong. The hardware is implemented by using a AVR ATMega88 microcontroller. The firmware is based on a software implementation of the USB 1.1 protocol. You can get the schematics and source code from the link below.
LEDLoad - controller for computer case LED’s: [Link]
The aim of the following project is the construction and development of an interface between a CMOS camera and a computer. The interface will allow a use to get images from the camera and to change the properties of the camera as brightness, luminance, etc. from the computer. Also some image tracking technology is implemented allowing the camera to track white objects and follow them with a servomotor.
The interface is based on the Atmel AVR ATmega16 microcontroller. The Camera called c3088 uses a CMOS image sensor OV6620 from Omnivision . It has a digital video port that supplies a continuous 8/16 bit image data stream. All the camera functions, such as exposure, gamma, gain, white balance, windowing, can be changed through I2C interface by writing in some registers.
The communication from the microcontroller to the camera to change the properties of the camera is made using the I2C. The images from the camera are read following the Zoom Video Port Format implemented by the camera. The images read are in black and white because only the Y channel is read. To control all this communications the microcontroller is connected to the computer via serial port. The microcontroller read commands from the computer and perform the appropriate actions. The serial port is also used to receive the images in BMP format. If you would like to start building this project, head to authors page for full info.
[Link]
