If you want to switch different IO-pins in different intervals
you must replace all delay()'s with non-blocking timing based on function millis():
as an everyday example with easy to follow numbers
delay() is blocking. As long as the delay is "delaying" nothing else of the code can be executed.
Now there is a technique of non-blocking timing.
The basic principle of non-blocking timing is fundamental different from using delay()
You have to understand the difference first and then look into the code.
otherwise you might try to "see" a "delay-analog-thing" in the millis()-code which it really isn't
Trying to see a "delay-analog-thing" in millis() makes it hard to understand millis()
Having understood the basic principle of non-blocking timing based on millis() makes it easy to understand.
imagine baking a frosted pizza
the cover says for preparation heat up oven to 200°C
then put pizza in.
Baking time 10 minutes
You are estimating heating up needs 3 minutes
You take a look onto your watch it is 13:02 (snapshot of time)
You start reading the newspaper and from time to time looking onto your watch
watch shows 13:02. 13:02 - 13:02 = 0 minutes passed by not yet time
watch shows 13:03. 13:03 - 13:02 = 1 minute passed by not yet time
watch shows 13:04. 13:04 - 13:02 = 2 minutes passed by not yet time
watch shows 13:05 when did I start 13:02? OK 13:05 - 13:02 = 3 minutes time to put pizza into the oven
New basetime 13:05 (the snapshot of time)
watch 13:06 not yet time
watch 13:07 not yet time
watch 13:08 not yet time (13:08 - 13:05 = 3 minutes is less than 10 minutes
watch 13:09 not yet time
watch 13:10 not yet time
watch 13:11 not yet time
watch 13:12 not yet time
watch 13:13 not yet time
watch 13:14 not yet time (13:14 - 13:05 = 9 minutes is less than 10 minutes
watch 13:15 when did I start 13:05 OK 13:15 - 13:05 = 10 minutes time to eat pizza (yum yum)
You did a repeated comparing how much time has passed by
This is what non-blocking timing does
In the code looking at "How much time has passed by" is done
currentTime - startTime >= bakingTime
bakingTime is 10 minutes
13:06 - 13:05 = 1 minute >= bakingTime is false
13:07 - 13:05 = 2 minutes >= bakingTime is false
...
13:14 - 13:05 = 9 minutes >= bakingTime is false
13:15 - 13:05 = 10 minutes >= bakingTime is TRUE time for timed action!!
So your loop() is doing
void loop()
// doing all kinds of stuff like reading the newspaper
if (currentTime - previousTime >= period) {
previousTime = currentTime; // first thing to do is updating the snapshot of time
// time for timed action
}
best regards Stefan