Adapter Power Supply (9VDC - 2A) PIC16F84A04/P Question1: What type of materials

Question1: What type of materials the sensor is made out of that contact the water

For LDR (light dependent resistor) datasheet and tutorial

I2C connection

Sparkfun hook up guide for force sensing resistor

Simply clip the Pulse Sensor to your earlobe or finger tip and plug it into your 3 or 5 Volt Arduino and you're ready to read heart rate

Adapter Power Supply (9VDC - 2A) PIC16F84A04/P Question1: What type of materialsThis is industry quality DC power adapter with 9V, 2A output. It has barrel jack connector. This adapter works well with arduino specially for duty applications that need relatively high current Specifications Input: 100 240V AC 50 60Hz Output : 9V, 2. 0A Dimensions: 80(L) x 45(W) x 30(H) mm Cable length: about 110CM Output adaptor : Barrel Jack