I need PCF8575 for use only 1 time relay? [SOLVED]

[Marcos Junior]

Hi again!

In my project i need only one time relay for ATS leds... same for only one time relay i will need PCF8575 or not?

Thx!

[Fernando Garcia]

Hi!

You can use any free pin.

The pin 7 is free and you can change the pins of functions that isn't needed for you.

Never use the same pin to 2 functions.

Best regards.

[Marcos Junior]

Thanks Fernando,
I will check the possibilities, because it would not change much code and leave the original Ferduino possible when you need to expand the functions have no problem because of changes I made.

Best regards

[Marcos Junior]

Hi again,

If change in a code a pin for time relay, would be something like this?

EX_in_code:

Code: Select all

// Pinos 22 à 41 reservados para o LCD.
...
const byte ozonizadorPin = 47;  // Pino que liga o ozonizador
const byte reatorPin = 48;      // Pino que liga o CO2 do reator.
...
...
const byte temporizador1 = 80;       // P0       // Pino que liga o timer 1.
const byte temporizador2 = 81;       // P1       // Pino que liga o timer 2.
...

and change a value 80 (time1) and 81(time2) to 47 and 48 from (ozonizadorPin,reatorPin)
or have to change more lines of code?

looking the code a pin 7 is reserved to touch
(
// Pinos 3, 4, 5, 6 e 7 reservados para o Touch.
)

taking advantage, will have a total of 6 relays, all are 5v, can connect directly to pin 5v with the mega temp sensors. or have to use an external source 5v?
I'm using the mega with a 10A 12v source and stepdown for 9v, is it right?
i will use the external source to the relay put another stepdown to 5v and linking the six relays?

1 relay to chiller
1 relay to heater
1 relay to time
3 relays to future expand



Thx

[Fernando Garcia]

Hi!

This way:

Code: Select all

const byte ozonizadorPin = 80; // Pino que liga o ozonizador
const byte reatorPin = 81; // Pino que liga o CO2 do reator.


And:

Code: Select all

const byte temporizador1 = 47; // P0 // Pino que liga o timer 1.
const byte temporizador2 = 48; // P1 // Pino que liga o timer 2.

looking the code a pin 7 is reserved to touch
(// Pinos 3, 4, 5, 6 e 7 reservados para o Touch.)

Pin 7 is used for touch on Ferduino Mega 2560.

I'm using the mega with a 10A 12v source and stepdown for 9v, is it right?

Good option to not heat the Arduino much.

i will use the external source to the relay put another stepdown to 5v and linking the six relays?

I think this option better.

Best regards