Arduino Module Analog AD Keyboard Module , Electronic Building Block

Electronic building blocks AD Keyboard Analog keyboard module

Description:

Use an analog port to read the five key states for Arduino save IO port. With Arduino sensor expansion board can be completed and buttons of interactive works.

Aruino test code:

/ / ADKeyboard Module

int adc_key_val [5] = {50, 200, 400, 600, 800};

int NUM_KEYS = 5;

int adc_key_in;

int key = -1;

int oldkey = -1;

void setup ()

{

pinMode (13, OUTPUT); / / we'll use the debug LED to output a heartbeat

Serial.begin (9600); / / 9600 bps

}

void loop ()

{

adc_key_in = analogRead (0); / / read the value from the sensor

digitalWrite (13, LOW);

key = get_key (adc_key_in); / / convert into key press

if (key! = oldkey) / / if keypress is detected

{

delay (50); / / wait for debounce time

adc_key_in = analogRead (0); / / read the value from the sensor

key = get_key (adc_key_in); / / convert into key press

if (key! = oldkey)

{

oldkey = key;

if (key> = 0) {

digitalWrite (13, HIGH);

switch (key)

{

case 0: Serial.println ("S1 OK");

break;

case 1: Serial.println ("S2 OK");

break;

case 2: Serial.println ("S3 OK");

break;

case 3: Serial.println ("S4 OK");

break;

case 4: Serial.println ("S5 OK");

break;

}

}

}

}

delay (100);

}

/ / Convert ADC value to key number

int get_key (unsigned int input)

{

int k;

for (k = 0; k <NUM_KEYS; k + +)

{