Small tutorial on Interfacing capacitance sensor to PIC

As you may know some PIC microcontrollers have integrated capacitance module that allows direct interfacing of capacitance touch sensors. IN following tutorial there is a PIC16F1937 microcontroller use which has a 16 channel capacitance module. Tutorial explains how to connect four capacitance touch sensors that are nothing more than simple electrodes connected to MCU pins. Four LEDs indicate which button is sensed. And great thing is that it is possible to implement multi-touch feature as well. Continue reading

Arduino based capacitive liquid sensor

Water or any other liquid level sensors can be handy around a house. It can be used to monitor a water tank level in a greenhouse or in other areas where liquid level has to be known. The idea is pretty simple – measure a capacitance charge between two metal plates/foils, which varies due liquid level change between them. Of course container has to be non metal. Probably most important part is to read capacitance. For this there is a handy Arduino Capacitive Sensing Library ready for you. To measure capacitance is to measure capacitors charge/discharge time through resistor. Don’t expect great precision with such materials used, but still this is a fun project to try out. Continue reading