This project is amazing - how simple construction can be comparing to its power. I wouldn’t say that it is easy to build project, but average electronics hobbyist could do this as DSO circuit and PCB image are ready for manufacturing.

Oscilloscope samples signals at 40MSPS frequency which is much more than most powerful AVR microcontrollers can be clocked. For this there is 40MHz clock source used which is passed through programmable logic (XC9572 from Xilinx) IC. Analog signals are passed through OPA2652 operational amplifier and low-pass filter with 20MHz bandwidth. Then filtered signal enters ADS830 ADC chip which is clocked with 40MHz frequency. Converted signal then goes to AVR ATmega162 microcontroller. From where it goes to 240×128 (LMG6402PFLR with HD61830B controller) graphical LCD.

Features of AVR DSO (eOscope):

• Maximum sample frequency: 40MSPS
• Maximum input frequency: 5MHz
• Maximum displayed frequency without aliasing: 10MHz
• Input circuit bandwidth: 20MHz
• Display resolution: 240×128 total, trace resolution 200×125
• Sensitivity: 40mV/div
• Coupling: DC
• Input impedance: 10K
• Power supply: single DC source 8V..10V, 1A
• No incremental mode
• Time base: 1s/div, 500ms/div, 200ms/div, 100ms/div, 50ms/div/, 20ms/div, 10ms/div, 5ms/div, 2ms/div, 1ms/div, 500us/div, 200us/div, 100us/div, 50us/div, 20us/div, 10us/div, 5us/div, 2us/div, 1us/div, 500ns/div
• Trigger: digitally adjustable
• Trace offset: digitally adjustable

Project files are free for non commercial use.

This is cool project to pay attention to. It can be used for PC modding or elsewhere where scrolling text effects are needed. Display is built of 50×7 LEDs that is controlled by AVR AT90S2313 microcontroller (may be substituted by ATtiny2313).

Text can be sent from computer via RS232 port or displayed from external EEPROM 2k memory where 768 characters can be stored. Fonts set of 256 different characters can also be programmed and mast be written to EEPROM before sending text to display. Hardware project with 3mm LEDs can be downloaded here. And latest firmware here. There might be minor changes are needed to adapt to newer WinAVR and ATtiny2313 microcontroller.

Windmetter or so called anemometer measures wind speed up to 17 meters/s. Wind speed is measured and logged over period of 1/12 of a year and is stored for 11 months. Log can be read any time by connecting a computer to station.

Anemometer is self powered from solar panel, which provides enough energy to run AVR ATmega88 controller circuit. Solar panel charges battery, which can provide enough energy for 50 days. Program is written in C language and can be compiled with WinAVR tools. Project it self is very well documented with lots of illustrations and detail explanation. It is really great thing for those who are construction their own weather stations.

Bright LEDs are cheap today. So many new projects with large amount of LEDs can be done. But there is one problem - large amount of LEDs consume large amount of energy. This is a project that implements special technique that allows driving efficiently hundreds of LEDs. This is a large PCB where 25×25 (625 total) LED grid is soldered. Resistors and transistors are positioned around the edges of message board. That entire grid is controlled by AVR Atmega164 microcontroller.

Displaying technique works as follows: microcontroller scans all display row by row through multiplexer. Scanning speed is fast enough to see all non flickering images. Project is published as open hardware. PCB and AVR-GCC project files are free to download. But if you want it quicker - you can always get a kit.

It is always good to have handy microcontroller development board where you could test, debug embedded programs. Generally speaking development boards have to be universal and also convenient for interfacing. So usually when people make these tings usually build in some periphery to be ready to use like RS232 interface, MMC/SD slots.

So here is one development board with ATmega128 microcontroller which is small but has lots of functionality ready to go like RS232, RS485, ISP, JTAG, MMC/SD connectors. Also it has 62kB of external RAM - so you can run really serious programs without wary. Don’t forget other interfaces like I/O, I2C, SPI, and RTC that are positioned in two additional pin-headers.