Bluetooth low energy (BLE) is designed to intermittently transmit information using a limited amount of power. This article provides the building blocks that allow you to add BLE to your projects for $5 (plus a one-time purchase of a $15 programmer).
June 28, 2017 by Mark Hughes
In this project, you'll learn how to wire an LED and flash it using the Raspberry Pi. Also, to isolate the Raspberry Pi's + 3.3VDC compliant output pins from supply voltages greater than this power source, an opto-isolator will be introduced as well.
December 11, 2015 by Don Wilcher