Water-DropletWater pump controller senses the level of water in a tank and drives the water pump. The circuit described here is built around timer IC1 (555). When the water level of tank goes below the low level marked by ‘L’ the voltage at pin 2 of IC1 becomes low. As a result, internal SR-flip-flop of IC1 resets and its output goes high. This high output pin 3 of IC1 drives relay driver transistor T1 (BC547) and energies relay RL1. Water pump gets mains power supply through n/o contacts of the relay and is powered on. It starts filling water in the tank. Continue Reading…

Controlling Home appliances is the interesting thing. You can easily switch ON or OFF using remote with one touch. But it has limitations within range of IR. Here we see the controlling appliances via your phone SMS. Now you can control your devices from any part of the world. Send SMS “ON” to switch on your fan/lights or any devices. Continue Reading…

This project slightly modifies the Google Android sample app called “Bluetooth Chat” so you can type a message in the Android app and that same message will appear on an LCD attached to an Arduino Uno.  Continue Reading…