Many of us have a pair of headphones connected to the output of the computer sound card us either to enjoy songs, or a game. Very likely your headphones and microphone, which also connect to the appropriate slot your sound card. But at some point broke down the female plug my sound card, and because quite a lot to change the plug when I put the headphones and when the speakers. A small structure is a sound card, USB, with stereo inputs / outputs, button to increase / volume button for volume and mute! When connected Windows will recognize as a sound card! With all the materials to be SMD, the cornered enough and fit into a small plastic box, which by one measure has a cable with USB plug, sound to go acoustic (Left / Right) and condenser microphones. The supply of (as imagined) is done by the USB port. The heart of the integrated circuit is PCM2902 of Burr-Brown by Texas Instruments. It is stereo 16-bit DAC and ADC, fully compatible with USB 1.1. DAC sampling frequencies are 32, 44.1 and 48 kHz, ADC has 8, 11.025, 16, 22.05, 32, 44.1 and 48 kHz. If you want more sound intensity, you will need to connect TDA 7050 amplifier to audio output.

The purpose of this project is to realize a Solar panel controller. Initially developed for a sailing boat, the target to reach was to control the level of charge and discharge and to protect a 12 volts lead battery connected to a 32 watts solar panel.

This circuit based around 74LS154 will extend PIC / AVR microcontroller output PINs from 4 to up to 16. It can also be used for extending parallel port output pins.

The LCD Terminal just like a normal terminal, it can connect to any host via RS-232 serial cable. A PC keyboard must connect to it as the input device and what ever you type will send to host via RS-232 and display on a 40x4 LCD. Data receive from host can also display on the LCD unit. You can use this device as any Unix/Linux machine's console.

Weather Station is PIC16F877A based and has a 4x20 LCD, a data logger output and accepts 1Wire wind instrument. It has a built-in APRS TNC. Connect it to your portable rig thru a DIN5 connector and you have a true portable weather station.

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