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With this tiny thing you can charge almost all devices that are charged via USB, like iPods or mobile phones, with only two AA-Cells.

This is a digital thermometer based on USB PIC16C745 microcontroller from Microchip and DS1820 sensor from Dallas Semiconductor. Temperature readings are sent over USB port in HIDCOMM USB mode to VB6 program on a PC. Hex program and sample Visual Basic 6 application is included.

The board supports driving two separate tri-color LEDs. More can be setup inline if desired. Currently the software only uses the second LED and its color represents the CPU load of the system in real-time. Blue for idle and gradients light blue, green, yellow, orange, and finally red indicating heavy CPU utilization. If the system fails to respond, the LED begins flashing RED to indicate a lack of communication from the software. This lets you easily identify a crashed machine in a rack for example.

USB Relay is a small hardware device to turn other devices on and off, using your computer. It is connected to your computer via usb.

Here's the new 6 channel USB relay card for switching different appliances, lamps or motors by a computer program via the USB interface. There are certain switching sequences can be programmed via computer. The card was dispensed on SMD technology and is thus the ideal craft project for beginners and novices. Those who do not always wanted with his computer what Steruern. This can be done with the help of a web application even over the Internet. About the SPI connector could even imagine the relay card to cascade with other relay boards. The relays max. 250V AC and have a switching current of 8A (depending on the used relay). Furthermore also 4 inputs, which are separated optocouplers, and monitors can be queried. AVR simulates a USB RS 232 interface can thus this relay, the card without problems using a terminal program or other software to be easily addressed. The USB driver in the AVR firmware was developed by Objective Development ( http://www.obdev.at/products/avrusb/projects-de.html ) and under the GPL2. Through this USB driver could have very special devices and SMD technology abandon. Her come out is a very compact board with dimensions of 100mm x 85mm. The setting of the simulated serial port is: 9600 baud, 8Datenbits, no parity and 1 stop bit further handshaking. To power supply reaches a normal 9 - 12V power supply.

Make a sound card is no more a complex issue. If you use great IC PCM2702 from BURR BROWN / Texas Instruments you can create a fully functional USB sound card. This sound card can be powered from USB port and has one stereo output. You don’t need to install any driver for Windows XP and Vista, because they are already inside. This is really plug and play.

We employ two UART boards in the course, one which can be connected to the serial connector of the PC (UART-RS232), and a second that can be connected to a USB port (UART-USB). The former is used in the lab and is part of the standard take-home equipment. The latter is part of the (limited!) number of take-home targets for students who are working on a Laptop without serial connector. In both cases, communication is done with the UART module of the microcontroller. In the case of the normal UART board, the MAX232 simply transforms the voltage levels to RS-232 standards (± 3-15V; in our case 12V, with LOW=+12V and HIGH=-12V). In case of the UART-USB, the FT232BM transforms the UART protocol to the USB protocol. This is transparent to the controller, which communicates over the normal TX and RX pins.

Why build my own USB to RS232 converter when there are adapters already available from many suppler? The Answer is simple: Neither the strand "USB to RS232 converter" actually worked *properly* with all the devices I tried. But, They did not seem to support ALL the RS232 lines. The USB to RS232 converter using the FT8U232AM and a Maxim-IC MAX235

With serial and parallel ports being phased out on new computers, hardware designers and hobbyists have no choice but to convert the USB port back to RS232 serial. FTDI have a very nice chip that does just that, the FT232AM. This chip converts USB to a standard high-speed serial port. The bonus with FTDI is the drivers are already written for you. All you have to do is design the hardware and download the serial USB drivers from FTDI's web site.

PowerSwitch provides 8 bits of parallel output intended to switch e.g. the power supply to electronic devices. The PowerSwitch firmware is accompanied by a command line tool for Unix to control the device. (The command line tool can also be compiled on Windows using minGW and libusb-win32.)