Im working on a 5V board which have 16 touch sensors in form of paired IR leds and phototransistors. They are hooked up to two shift registers (74hc165) which have a high input level of 2V. The idle V is about 0.5 (when not touching). To sense a touch with a finger it needs to be about 3cm from the sensor which is too close. So my idea is to use four LM324 quad opamps to increase the sensitivity of the touch sensors. Im thinking I will first use a suitable resistor to mute the idle voltage to 0V and from there connect to the non inverting input of the op amp.
Does this seem to be the correct solution or is there some simpler solution I can use? Is the LM324 the correct type of op amp or is there a better suited one?
The project is a modular board for an interactive led coffee table which can play different games like the classic low pixel games and chess. The first proto will be 16 boards and 256 pixels controlled by Teensy 3.1.
Im currently fine tuning the first proto board and this is one thing I need to improve (touch sensor sensitivity).
Does this seem to be the correct solution or is there some simpler solution I can use? Is the LM324 the correct type of op amp or is there a better suited one?
The project is a modular board for an interactive led coffee table which can play different games like the classic low pixel games and chess. The first proto will be 16 boards and 256 pixels controlled by Teensy 3.1.
Im currently fine tuning the first proto board and this is one thing I need to improve (touch sensor sensitivity).