Capacitive Relay Software Implementation on Arduino

The author of Instructables under the nickname ShaneCunningham proposes to implement a capacitive relay on Arduino programmatically. Of the additional parts, only capacitive sensors and resistors themselves will be required. No external hardware generators. In software homemade involved this and this third-party developments.

Capacitive sensors - two-layer, three-pin. The master makes them do it yourself. A cardboard square with a side of 300 mm is pasted over with foil - this will be the output connected to the common wire. On top of it places a cardboard square with a side of 100 mm, also glued with foil. On it, the foil layer is divided into two parts along a contour similar to an oscillogram of rectangular pulses. These will be two more conclusions.





Each of the manufactured sensors is equipped with a 1 MΩ resistor. If there is only one sensor, connect it as shown below. If there are several of them, you will have to use the Arduino conclusions - two per sensor - and take this into account in the sketch.



Here's what the wizard does:






Composes a sketch that sends data taken from the sensor via the serial interface:

///////////////////////////////////////

void loop () {
long total1 = cs_4_2.capacitiveSensor (30);

Serial.println (total1);

/////////////////////////////////////////

Code for Communicating with Processing over Serial

* /

int val1 = 0;

int val2 = 0;

int val3 = 0;

int inByte = 0;

CapacitiveSensor cs_4_2 = CapacitiveSensor (4.2); // 1M resistor between pins 4 & 2, pin 2 is sensor pin, add a wire and or foil if desired

CapacitiveSensor cs_4_6 = CapacitiveSensor (4.6); // 1M resistor between pins 4 & 6, pin 6 is sensor pin, add a wire and or foil

void setup () {

cs_4_2.set_CS_AutocaL_Millis (0xFFFFFFFF); // turn off autocalibrate on channel 1 - just as an example

cs_4_6.set_CS_AutocaL_Millis (0xFFFFFFFF);

Serial.begin (9600);

pinMode (2, INPUT);

pinMode (6, INPUT);

// pinMode (8, INPUT);

establishContact (); // send a byte to establish contact until receiver responds

void loop () {

// if we get a valid byte, read inputs:

if (Serial.available ()> 0) {

// get incoming byte:

inByte = Serial.read ();

// long start = millis ();

long total1 = cs_4_2.capacitiveSensor (30);

long total2 = cs_4_6.capacitiveSensor (30);

// long total3 = cs_4_8.capacitiveSensor (30);

// delay (10);

val1 = map (total1, 700, 2300, 0, 255); // sensor values ​​from calibration are mapped to here - begins to detect human proximity at 700 (4 "away), hand nearly touching sensor at 2300

val2 = map (total2, 30, 175, 0, 255);

// val3 = map (total3, 0, 13000, 0, 255);

Serial.write (val1);

Serial.write (val2);

//Serial.write(val3);

//Serial.print(val1);

// delay (50);

}

void establishContact () {

while (Serial.available () <= 0) {

Serial.print ('A');

delay (300); }

The wizard organizes further analysis of the incoming information on a PC in the Processing environment.





But this is only the beginning of the experiment. In the future, you can use it to process signals from Arduino sensors - the same thing, or, if its resources are not enough, one more.