Not exactly. You want to mark the time when the blink state is selected. Something along the lines of this (not able to compile as your LCD object declaration doesn't work for me...):
// Pin assignement
const int ledPin = 7;
const int btnPin = 8;
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3f, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
enum fcnMode
{
OFF=0,
BLINK1,
BLINK2,
NBSTATE
}; // OFF = 0 and NBSTATE=7
int ledState = LOW; // ledState used to set the led
unsigned long buttonState = 0;
int funcState = 0;
unsigned long currentTime1, currentTime2, currentTimebtn, currentTimeact1, currentTimeact2; // will store current time
unsigned long previousTime1, previousTime2, previousTimebtn, previousTimeact1, previousTimeact2; // will store last time led was updated
const long PERIOD1 = 25; // interval at which to blink (microseconds) = 20 Hz
const long PERIOD2 = 12.5; // interval at which to blink (microseconds) = 40 Hz
const long PERIODact = 5000; // amount of time to keep blinking (milliseconds)
const long PERIODbtn = 150; // (microseconds)
/******************************************************************\
SETUP
\******************************************************************/
void setup()
{
lcd.begin(16, 2); // LCD
pinMode(btnPin, INPUT_PULLUP);
pinMode(ledPin, OUTPUT);
}
/******************************************************************\
Main Function of the code
\******************************************************************/
void loop()
{
buttonPressed();
setMode();
}
/******************************************************************
SUBFUNCTIONS
\******************************************************************/
void buttonPressed()
{
currentTimebtn = millis();
if (currentTimebtn - previousTimebtn >= PERIODbtn)
{ // push button delay to prevent fast toggling between funcstates when pressed
previousTimebtn = currentTimebtn;
if (digitalRead(btnPin) == HIGH)
{
funcState += 1;
if (funcState >= NBSTATE) //changed from '4'
funcState = 0;
lcd.clear();
switch( funcState )
{
case OFF:
digitalWrite(ledPin, LOW);
lcd.setCursor(4,0);
lcd.print("*Idle*"); // LCD main idle screen
break;
case BLINK1:
lcd.setCursor(2,0);
lcd.print("Mode: 20 Hz"); // LCD shows selected mode
currentTimeact1 = millis();
previousTime1 = currentTimeact1;
break;
case BLINK2:
lcd.setCursor(2,0);
lcd.print("Mode: 40 Hz"); // LCD shows selected mode
currentTimeact2 = millis();
previousTime2 = currentTimeact2;
break;
default:
break;
}
}
}
}
void setMode()
{
// All Off
switch (funcState)
{
case OFF:
break;
case BLINK1:
blinkled1();
break;
case BLINK2:
blinkled2();
break;
}
}
void blinkled1()
{
currentTime1 = millis();
if (currentTime1 - previousTime1 >= PERIOD1)
{
// defines the blinking frequency
// save the last time you blinked the led
previousTime1 = currentTime1;
// if the led is off turn it on and vice-versa:
if (ledState == LOW)
{
ledState = HIGH;
}
else
{
ledState = LOW;
}
// set the led with the ledState of the variable:
digitalWrite(ledPin, ledState);
}
if (currentTimeact1 - previousTimeact1 >= PERIODact)
{
// checks if time after the start is equal or longer than 5 seconds to stop blinking
previousTimeact1 = currentTimeact1;
ReturnToIdleState();
}
}
void blinkled2()
{
currentTime2 = millis();
if (currentTime2 - previousTime2 >= PERIOD2)
{
// defines the blinking frequency
// save the last time you blinked the led
previousTime2 = currentTime2;
// if the led is off turn it on and vice-versa:
if (ledState == LOW)
{
ledState = HIGH;
}
else
{
ledState = LOW;
}
// set the led with the ledState of the variable:
digitalWrite(ledPin, ledState);
}
if (currentTimeact2 - previousTimeact2 >= PERIODact)
{
// checks if time after the start is equal or longer than 5 seconds to stop blinking
previousTimeact2 = currentTimeact2;
ReturnToIdleState();
}
}
void ReturnToIdleState( void )
{
lcd.clear();
funcState = OFF; //go back to iddle screen
digitalWrite(ledPin, LOW);
lcd.setCursor(4,0);
lcd.print("*Idle*"); // LCD main idle screen
}//ReturnToIdleState