I had searched a lot once for this type of circuit, although my searches were a circuit made with Microchip PIC Series. 6 relay control can be done via usb port. There are computer program pcb code usb driver and schematic files. The supply of the circuit is SPI and RS232 connections on the 9-12 volt ac regulated section. there is.
In fact, there are simpler and cheaper circuits to control relays with a computer (Device Control with Computer), but since these circuits make port inquiries when the computer is turned on, this problem can be avoided in the system where a microcontroller is used.
USB Relay Control Project
New 6-channel USB relay board for switching various devices, lamps or motors via USB interface according to a computer program. Certain switching sequences can be programmed via a computer.
This board does not use SMD material and is therefore an ideal crafting project for beginners and beginners. Who doesn’t want to always check something with their computer? This can then be done even over the Internet with the help of a web application.
It is even conceivable to cascade the relay board with other relay boards via the SPI connector.
The relays make a maximum switching of 250V AC and have a switching current of 8A (depending on the relay used). In addition, 4 inputs separated by optocoupler can be queried and monitored. The AVR simulates a USB RS 232 interface so this relay board can be easily addressed via a terminal program or other software.
USB driver in AVR firmware comes from company development target and is subject to GPL2. This USB drive made it possible to forego proprietary components and SMD technology. The result is a very compact circuit board measuring 100mm x 85mm.
The settings for the simulated serial interface are: 9600 baud, 8 data bits, no parity and 1 stop bit, and no handshake. A normal 9 – 12V plug power supply is sufficient for the power supply.
The relays switch max. 250V AC and have a switching current of 8A (depending on the relay used). In addition, can also use 4 inputs, which are isolated by optocouplers, are queried and monitored.
The AVR simulates a USB RS 232 interface and so you can relay card can be easily addressed without problems via a terminal program or other software. The USB driver in the AVR firmware comes from the company objective development 6 Channel USB relay card to switch from various appliances, lamps or motors by a computer program via the USB interfaceThis can then using a web application even over the Internet.
About the SPI connector would even be possible to relay card with other relay cards to cascade. The relay switch max. 250V AC and have a switching current of 8A (depending on set relay). Also you can also 4 inputs, the optocoupler are separated, queried and monitored. The AVR simulates a USB interface RS 232 thus can relay this card without problems on a terminal program or other software to be easy.
Source: ulrichradig.de/ USB Relay Control schematic pcb Atmega8 source code files alternative link:
Password: 320volt.com
Published: 2008/10/16 Tags: atmega8 projects, avr project, microcontroller projects
Embedded RTL8019AS Web Server Project ATMega103
I quickly was able to appeal to the network card via a 8-bit data bus. The connectivity of the network card and thus the RTL8019AS chip via two 8-bit ports of the processor and an ISA slots. On external components such as memory was deliberately omitted from the beginning to keep the replica easy and the costs as low as possible. This of course had disadvantages in the implementation of the TCP / IP stack. The TCP implementation has been reduced to the extent that one can hardly speak of TCP / IP stack. The data are received and answered Packet way. Also, TCP security mechanisms due to the memory not implemented. The web server is therefore being able to answer incoming questions and to make web pages, but can not respond to transmission errors as defined in the TCP standard [RFC793].
AVR Web Server