keyboard switches matrix in embedded c


Switch Matrix in embedded c

A keyboard matrix is a circuit used in most electronic computer keyboards in which the key switches are connected by a grid of wires. Without a matrix circuit, each switch would require its own input pin to the controller. Keyboard switch matrices are arranged in rows and columns. if a key is pressed, a column wire makes contact with a row wire and completes a circuit. This closed circuit, triggers the algorithm in the controller and output is given.

keyboard switches matrix in embedded c
keyboard switches matrix in embedded c

CODE FOR BASIC BUTTON MATRIX AND TO CONTROL LEDs.

//4*3 Switch Matrix

//all 12 outputs are given with a LED turned ON for 0.8 second

//LDR* are the switches

//LDR1-LDR3 is the row

//LDR4-LDR7 is the column

//LED* are the outputs

//The output can be changed based of the needs



int LDR1 = A0;

int LDR2 = A1;

int LDR3 = A2;



int LDR4 = A3;

int LDR5 = A4;

int LDR6 = A5;

int LDR7 = A6;



int LED1 = 13;

int LED2 = 12;

int LED3 = 11;

int LED4 = 10;

int LED5 = 9;

int LED6 = 8;

int LED7 = 7;

int LED8 = 6;

int LED9 = 5;

int LED10 = 4;

int LED11 = 3;

int LED12 = 2;



void setup()



{

pinMode(LDR1, INPUT);

pinMode(LDR2, INPUT);

pinMode(LDR3, INPUT);

pinMode(LDR4, INPUT);

pinMode(LDR5, INPUT);

pinMode(LDR6, INPUT);

pinMode(LDR7, INPUT);

pinMode(LED1, OUTPUT);

pinMode(LED2, OUTPUT);

pinMode(LED3, OUTPUT);

pinMode(LED4, OUTPUT);

pinMode(LED5, OUTPUT);

pinMode(LED6, OUTPUT);

pinMode(LED7, OUTPUT);

pinMode(LED8, OUTPUT);

pinMode(LED9, OUTPUT);

pinMode(LED10, OUTPUT);

pinMode(LED11, OUTPUT);

pinMode(LED12, OUTPUT);

}

void loop()

{

if ((analogRead(LDR1) < 150) && (analogRead(LDR4) < 150))

{

digitalWrite(LED1, HIGH);

delay(800);

digitalWrite(LED1, LOW);

}

else if ((analogRead(LDR1) < 150) && (analogRead(LDR5) < 150))

{

digitalWrite(LED2, HIGH);



delay(800);

digitalWrite(LED2, LOW);

}

else if ((analogRead(LDR1) < 150) && (analogRead(LDR6) < 150))

{

digitalWrite(LED3, HIGH);

delay(800);

digitalWrite(LED3, LOW);

}

else if ((analogRead(LDR1) < 150) && (analogRead(LDR7) < 150))

{

digitalWrite(LED4, HIGH);

delay(800);

digitalWrite(LED4, LOW);

}

else if ((analogRead(LDR2) < 150) && (analogRead(LDR4) < 150))

{

digitalWrite(LED5, HIGH);

delay(800);

digitalWrite(LED5, LOW);

}

else if ((analogRead(LDR2) < 150) && (analogRead(LDR5) < 150))

{

digitalWrite(LED6, HIGH);

delay(800);

digitalWrite(LED6, LOW);

}

else if ((analogRead(LDR2) < 150) && (analogRead(LDR6) < 150))

{

digitalWrite(LED7, HIGH);

delay(800);

digitalWrite(LED7, LOW);



}

else if ((analogRead(LDR2) < 150) && (analogRead(LDR7) < 150))

{

digitalWrite(LED8, HIGH);

delay(800);

digitalWrite(LED8, LOW);

}

else if ((analogRead(LDR3) < 150) && (analogRead(LDR4) < 150))

{

digitalWrite(LED9, HIGH);

delay(800);

digitalWrite(LED9, LOW);

}

else if ((analogRead(LDR3) < 150) && (analogRead(LDR5) < 150))

{

digitalWrite(LED10, HIGH);

delay(800);

digitalWrite(LED10, LOW);

}

else if ((analogRead(LDR3) < 150) && (analogRead(LDR6) < 150))

{

digitalWrite(LED11, HIGH);

delay(800);

digitalWrite(LED11, LOW);

}

else if ((analogRead(LDR3) < 150) && (analogRead(LDR7) < 150))

{

digitalWrite(LED12, HIGH);

delay(800);

digitalWrite(LED12, LOW);

}}

Summary :

In this article we saw keyboard switches matrix in embedded c so about this section you have any query then free to ask me

Name of intern who share this task : Pratham bhomkar

I am Mr. Sachin pagar the founder of Pythonslearning, a Passionate Educational Blogger and Author, who love to share the informative content on educational resources.

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