llee WROTE:i am newbie and i am using SN-M114 as my soil moisture sensor for my project. I am confused with the schematic diagram attach with SN-M114. I am using PIC16F877A. Can i just connect the analog output with my PIC analog input without any additional component. Can i just connect it like connect the LM35?
Yes, just connect pin 1 of J3 to the analog input of your PIC like LM35 should work. Of course you also need Vcc and Gnd to pin 2 & pin 3.
To plot a characteristic curve of the sensor, you can actually connect a variable resistor (100K potential meter) between J1 and J2. +5V to pin3 and GND to pin 2 and a voltmeter to pin 1 & 2 of J3. Slowly turning the Var Resistor, take the voltage for every 0.5V change and measure the resistance of the Var resistor should give you a nice curve of how the sensor behaves.
Allen
Posted: Tue Apr 24, 2012 11:42 pm