How a inverter air conditioning system communicate

Projects Networking, Protocols, and Devices
1

Hi, :wave::wave:
I had a question that how does outdoor unit and a indoor unit of a air con communicate using a signal wire.

So , i hooked the communication wire to an oscilloscope to visualise it . I have attached signal image document.

IMG_20231014_181747773~2
IMG_20231014_181747773~23437×944 386 KB

It is same as of UART. So i hooked it to the serial pin of the ardunio and tried to decode it by changing baud rates, but it did not work, nothing got print to it.

So i decided to decode it manually. By browsing i found that the pulse with duration
32+88 is a 1 and pulse with duration 32+48 is a 0 and the long pulse the gap between the data stream.
I decoded it the format of binary as 1 and 0.
But I found that every 3 minutes it changes the
Pattern.

So my question is can a ardunio do it for me??
If yes!!
how should i program??

2

Hello allen_coelho

Have you looked in the HVAC equipment manufacturer's operating manual?

1 Like
3

Are you sure it is not VPWM (Variable Pulse Width Modulation)?

4

they have not provided any details about it. instead then have only provided the wiring diagram of the whole unit.

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I am not sure. But can u provided the link to understand better about variable pulse width modulation .

thank you
for the reply..

6

Thank you for the reply..

7

Do you understand PWM (Pulse Width Modulation)? If you do not understand PWM then you will be lost with VPWM. As far as links there are are probably hundreds if not thousands that will explain it. Start here and exercise your search engine.

8

No, it isn't. UART serial bit time is constant and the same for both 1 and 0 bits, which is completely inconsistent with your timing measurements.

9

What is your AC, (or inverter ), model/type... etc.? Datasheet or link.

10

The model a I am not sure.
But the company of the aircon is samsung and it has two unit to operate a indoor unit and a outdoor unit. As per the information i got the indoor unit sends the pulse to the out door unit to run the compresser

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So I don't want it to be UART , i only need the ardunio to perform calculation as 1 and 0 as i did manualy

12

Hello allen_coelho

Take a search engine of your choice and ask the WWW for 'aircon samsung +communication interface' to collect some data to be sorted out to get the needed information.

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Yes I searched for the text you sent but I did not get any information.

But do not want, what the information is,
instead I need to decode it as 1 and 0 using ardunio.

Thank you for the suggestion :smiling_face:

14

Do you have the operating manual?
If yes, look model.

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See if this link help.

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