Attiny85 sketch "set temprature to thermostat"

I tried the sketch: “Attiny85_set_temprature_to_thermostat_0”, wanting to change the desired temperature of my house thermostat.

The used thermostat, is this: “W1209 12V Digital thermostat Temperature Control Switch sensor Module”.

I want to lower the desired temperature “4 ° C” at night, and after a few hours to restore the desired temperature “4 ° C” up again. I use an external timer and give commands, high - low, to the attiny85.
I have connected the thermostat buttons on the Attiny85.(SET-DOWN-UP)

Τhe problem is that the program is repeated constantly, relegating not once as would like the desired temperature, but again and again … command timer remains unchanged for many hours …

So I used the sketch “Attiny85_set_temprature_to_thermostat”, which is the same but with sleep_mode.

I have the desired effect with it.
I would like to ask, is there any other way to achieve the desired effect without using the sleep_mode;

Cause, I have one more promplem:
The attiny restarts while my relay switches on or off…
This is a noise problem, that resets the attiny…

But maybe, the noise producted by the relay, wakes up the attiny from the sleep??
This is the reason i want to programm it with out the sleep mode…

Attiny85_set_temprature_to_thermostat_0.ino (1.28 KB)

Attiny85_set_temprature_to_thermostat.ino (1.93 KB)

Could you post a schematic and/or an image and/or a description of your circuit?

Some things to consider:

In your code, you're not using INPUT_PULLUP for your timer_PIN input ... are you using an external pullup or pulldown resistor? (depends on your circuit connections)

Perform an action when an input condition "changes".

Refrain from using delays ... use millisecond timers as in "blink without delay" example.

Thanks for the quick response!

I’m using external pullup resistor (10K).
and a 10K resistor to the reset pin, for more stable (noise resets)…

“Perform an action when an input condition “changes””
any excample for this action, please!..

any excample for this action, please!.

The StateChangeDetection example in the IDE

Recommend external 10K pullups on P2, P3 and P4.

dlloyd: Recommend external 10K pullups on P2, P3 and P4.

What does pulling up or down output pins do?

Also, looking at the diagram, wouldn't it be better to wire transistors or even optocouplers across those buttons?

Without with out the resistor, the input is floating and has a very high input impedance. Reading an input that is disconnected to anything external will result in random HIGH or LOW values.

Using pullup or pulldown resistors (values within operating range) on outputs does nothing.

There is not any problem with pins P2, P3 and P4, cause (my mistake, Idont have it in the shematic, so sorry...) I also have three transistors there!! and 3 10k resistors.

you see Ι "simulate" STM8S's buttons press by the attiny, grounding them, excactly the way manualy press the buttons.

The problem is the "loop", that runs the orders again and again, than the only one time on every pin's change, that is what I want.... So, I'll try the "State Change Detection" example and I'll let you know....

P2, P3 and P4 are outputs.
OP is not trying to read button presses, but rather to spoof button presses.

Is this correct: If the button panel and the Arduino have the same ground, then I would think a transistor across the button, and the output pin with a resistor to the gate of the transistor would do this, as it would do the same thing that a button press would normally do: close the connection to the ground. If they do not have the same ground, an optocoupler could close the circuit in the button panel when activated form the Arduino.

(I’ve only been playing with electronics since christmas, when I got my starter kit. Hence the questions.)

Edit to add:

Apostolos1:
So, I’ll try the “State Change Detection” example and I’ll let you know…

Yes. You don’t want to do things whenever the input is high or low, but when it goes from high to low or from low to high.

Thank you all very much !!!
The new “sketch” worked perfectly!!

Attiny85_set_temprature_to_thermostat_0.ino (1.63 KB)

Jobi-Wan: P2, P3 and P4 are outputs. OP is not trying to read button presses, but rather to spoof button presses.

Is this correct: If the button panel and the Arduino have the same ground, then I would think a transistor across the button, and the output pin with a resistor to the gate of the transistor would do this, as it would do the same thing that a button press would normally do: close the connection to the ground. If they do not have the same ground, an optocoupler could close the circuit in the button panel when activated form the Arduino.

Yes, it is correct!!