If you need to charge LiPo batteries, this simple charger will do just that, and do it fast! The USB LiPo Charger is a basic charging circuit that allows you to charge 3.7V LiPo cells at a rate of 500mA or 100mA. It is designed to charge single-cell Li-Ion or Li-Polymer batteries.
This is a great inexpensive option for wireless communication; it's an ISM band FSK transceiver module implemented with a unique PLL. These modules operate in the 434MHZ band and fully comply with FCC and ETSI regulations.
This is a small and very easy to use audio sensing board with three different outputs. The Sound Detector not only provides an audio output, but also a binary indication of the presence of sound, and an analog representation of its amplitude.
This complete module is built upon the same technology as the ET-301, but includes on-board voltage regulation, LED status indicator, battery backed RAM, and a built-in patch antenna! 6-pin interface cable included. This EM-506 GPS module is powered by SiRF Star IV, it can provide you with superior sensitivity and performance even in urban canyon and dense foliage environment.