Hi all,
It's my first post here 
I have been looking for an item like this for the past few days and couldn't find it but somehow figured to make my setup work and thought some people might find it helpful as well so here it is..
When configuring a two channel relay module (link ) it's nice to control both the ON as well as OFF time of both channels simultaneously. There are plently examples online in which this is done by delay() but this doesn't provide individual control of each channel.
Hope this helps:
const int RELAY1 = A0; //definition of channel 1 data pin.
const int RELAY2 = A1; //definition of channel 2 data pin.
int RELAY1State = LOW; //initial state of channel 1.
int RELAY2State = LOW; //initial state of channel 2.
const unsigned long interval1[] = {1000, 5000}; //time ON, time OFF.
const unsigned long interval2[] = {2000, 2000}; //time ON, time OFF.
unsigned long previousMillis1 = 0; //setting channel 1 millis() timing to 0.
unsigned long previousMillis2 = 0; //setting channel 2 millis() timing to 0.
void setup() {
pinMode(RELAY1, OUTPUT); //initiate channel 1.
pinMode(RELAY2, OUTPUT); //initiate channel 2.
}
void loop() {
unsigned long currentMillis = millis(); //time as stored value.
if (currentMillis - previousMillis1 >= interval1[RELAY1State])
{
previousMillis1 = currentMillis;
if (RELAY1State == LOW)
{RELAY1State = HIGH;}
else {
RELAY1State = LOW;
}
digitalWrite(RELAY1, RELAY1State);
}
if (currentMillis - previousMillis2 >= interval2[RELAY2State])
{
previousMillis2 = currentMillis;
if (RELAY2State == LOW)
{RELAY2State = HIGH;}
else {
RELAY2State = LOW;
}
digitalWrite(RELAY2, RELAY2State);
}
}