Before starting this Ethernet project the author did of course some prototyping and then he noticed alreadythat UDP was not a problem with lots of space left on the atmega88. Therefore he was quite confident that TCP + HTTP will work. TCP/IP was invented more than 25 years ago. Todays microcontrollers provide almost the computing power a standard computer had at that time. No java or xml was used at that time. Things were done in smart and efficient ways.
As you can imagine this web-server code is written for a friendly environment. Don’t put it on the open internet. The code uses e.g the incoming packet to build from it the outgoing packet. An attacker who sends a mal formed IP packet might be able to confuse the TCP/IP stack. The code is verified with a lot of different browsers and a number of operating systems. It was tested Linux, BSD Unix, Win 98, Win XP, Mac OS-X with a number of different web browsers. It works very well but it was not tested agains atacks and destroy tests.
What is Ginger ? Ginger is yet another physical computing platform, which is similar to gainer (http://gainer.cc). The goal of project is to develop PC Platform
Ginger makes use of avr-usb (http://www.obdev.at/avrusb/) for the implementation of USB interface. Thanks to avr-usb, no external USB-serial bridge chip is required to interface host PC, and this makes ginger hardware simple. ATmega88 is chosen because it is available in AKIZUKI-denshi, where many electric parts are sold in bargain price.(We love the store).
In Macintosh platforms, you don’t need to install software drivers, as the device is recognized as /dev/cu.usbmodem*. In Windows, please use ginger.inf provided with source code in tarball.
I remember when i was a kid, i was just starting with electronics, and i was very curious about this kind of systems. They were present in every contest show on tv. It’s cool that someone developed and published a project like this. The system is controlled by an ATmega88, and the voting pads interconnect trough RS-485. After the voting is done, a Java application that runs on the PC generates bar graphs.
It seems generating sync-ed sound and video on AVR its not that easy. AVR Atmega88 microcontroller is clocked at 20MHz and so it generates 45 full VGA display lines at almost 60Hz frame rate. Sound is generated during VGA horizontal blanking periods. That gives a sampling rate of 31496kHz which is enough for good chip-sound quality. Sound player is capable to play four sound channels. And all that beauty is programmed in pure assembly language for best performance.
Generate Sound and Video on the same AVR chip:[Link] - [Via]
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.
