Timer for UV lights,diy pcb exposure box

Using Arduino Microcontrollers
1

Hi, I'm making UV pcb exposure box,i have everything setup,and I would like arduino to control working time of UV lights,I have relay and I don't know how to make a code and what to control it with.I have cuple of momentary switches and lcd display.I hope someone can help me with this,what shoud I do,thanks.

2

tell more.. component details for relay.
The code you need isn't much..

3

So I have arduino nano,LCD,momentary switches,relay(it works on arduino,I tested it) and 220v UV light bulb,I would need a program that lets me select time by clicking buttons.I don't know how to explain it better,im new to arduino and english is my second language,so sorry if you don't understand.Thanks

4

If time is fixed, you only need the 'start-command' (an SPST push-button)
if we assume :

  • relay need a high puls.
  • push-button connects pin to gnd.
#define lightpin 4 // pin 5 for relay
#define startpin 5 // 
#define lightperiod 20000 // 20 seconds when triggered
void setup()
{
  pinMode lightpin(OUTPUT);
  pinMode startpin(INPUT_PULLUP);
}
void loop()
{
  while (digitalRead(startpin)) ;  // wait for you to push button
  digitalWrite(lightpin,HIGH);  // turn light on
  delay(lightperiod); // just wait
  digitalWrite(lightpin,LOW);  // turn light off  
}

Add code for your LCD
Add two more pushbuttons, one=incr. time, the other=decr. time

byte lightpin=4 ;
byte startpin=5;
byte addpin=6;
byte subpin=7;
long lightperiod = 20000; // 20 sec defalt

void shownumber()
{
  // add code to show "lightperiod" on the lcd
}

void setup()
{
  pinMode (lightpin,OUTPUT);
  pinMode (startpin,INPUT_PULLUP);
  pinMode (addpin,INPUT_PULLUP);
  pinMode (subpin,INPUT_PULLUP);
  shownumber();
}

void loop()
{
  if (!digitalRead(startpin)) ;  // wait for you to push button
  {
    digitalWrite(lightpin, HIGH); // turn light on
    // tell on display ??
    delay(lightperiod); // just wait
    digitalWrite(lightpin, LOW); // turn light off
  }
  if (!digitalRead(addpin))
  {
    lightperiod += 1000; // add a second
    shownumber();
  }
  if (!digitalRead(subpin))
  {
    if (lightperiod>1000)  lightperiod -= 1000; // add a second
    shownumber();
  }
  delay(100); // to avoid 'racing' numbers.. try without it
}