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Author Topic: Trying to control Mitsubishi Heat Pump Air Conditioning Unit  (Read 8730 times)
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Thanks for the web site - I may look into that.

Cheers

Chris
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Hello,

I'd be very interested in any news on this subject.

I tried to decode a Mitsubishi remote control today, using Chris's codes from the Crowe web site. Unfortunately, there was not much similarity with the recorded data I received.

The train of bits was much longer than I anticipated, and also were repeated once more from the remote.

As to the different lengths in the measurements you did with the arduino remote, the numbers indicate as follows :
A preamble comes first, with a logic 1 level for about 3200 uS, followed by a shorter low period.
A logic 1 is decoded if the low period is >1.5 times the previous high period. This has worked for me, anyway.
A logic 0 is decoded if the low period is shorter than the high period, or <1.5 times the high period.

I think the receivers might be particular to the timing of the high and low periods, but maybe not.

I would guess that the frequenzy of the PWM should be around 37kHz on the IR emitter. If the frequenzy is missed somewhat it is mostly the range that would be shorter. The more off, the shorter the range, until a point where it is not getting an IR signal through the receiving fiilter. A frequenzy between 34 to 42 on a 38kHz filter should pass without too much trouble.

I did not get a very good look at the repeating train, but assume it is a repeat of the first. Due to the first numbers not looking at all like Chris's decoded numbers, I did not dig in further. Yet :-)

A decoder can easily be made in Visual Basic within Excel, for instance, where the high+low times were compared with th 1.5 multiplier.

I'd also be very interested in the story of the defective Mitsu, whether it was a general failure or might have been caused by wrong codes being sent from the arduino. This is a bit scary, if you get the checksum right, and the command contains an impossible combination. One would think that the manufacturer of the pump would safeguard towards such an event, but they can hardly be held accountable as long as anyone tampers with the command.

If I can help with the decoding, please let me know.


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Here's the recording I got, for temperatures from 16 to 31 degrees. I have separated the first bytes until temperature bits occur (at the '-' mark), trying to compare a header with what Chris found.

Temperature is 4 bit, but other bits also change later on. I suspect a checksum at the end.

The end is also a bit unstable, where the recorded length is different for some of the readings. Don't know why, might be my homemade recorder for all i know. Therefore, where differences occur towards the end, data is probably not trustworthy.

16:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0000 0000000000110101000111101110000000000000000000000000010010000000001000010000 0001101 01011000100110100110110010010000000000000000000010000010000 0000 0000000000110101000111101110000000000000000000000000010010000000001000010000000110100

17:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1000 0000000000110101001011101110000000000000000000000000010010000000001000010000 1001100 01011000100110100110110010010000000000000000000010000010000 1000 000000000011010100101110111000000000000000000000000001001000000000100001000010011000100

18:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0100 0000000000110101001011101110000000000000000000000000010010000000001000010000 0101100 01011000100110100110110010010000000000000000000010000010000 0100 000000000011010100101110111000000000000000000000000001001000000000100001000001011000100

19:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1100 0000000000110101001011101110000000000000000000000000010010000000001000010000 1101100 01011000100110100110110010010000000000000000000010000010000 1100 000000000011010100101110111000000000000000000000000001001000000000100001000011011000100

20:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0010 0000000000110101001011101110000000000000000000000000010010000000001000010000 0011100 01011000100110100110110010010000000000000000000010000010000 0010 000000000011010100101110111000000000000000000000000001001000000000100001000000111000100

21:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1010 0000000000110101001011101110000000000000000000000000010010000000001000010000 1011100 01011000100110100110110010010000000000000000000010000010000 1010 000000000011010100101110111000000000000000000000000001001000000000100001000010111000100

22:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0110 0000000000110101001011101110000000000000000000000000010010000000001000010000 0111100 01011000100110100110110010010000000000000000000010000010000 0110 00000000001101010010111011100000000000000000000000000100100000000010000100000111100000

23:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1110 0000000000110101001011101110000000000000000000000000010010000000001000010000 1111100 01011000100110100110110010010000000000000000000010000010000 1110 000000000011010100101110111000000000000000000000000001001000000000100001000011111000000

24:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0001 0000000000110101001011101110000000000000000000000000010010000000001000010000 0000010 01011000100110100110110010010000000000000000000010000010000 0001 000000000011010100101110111000000000000000000000000001001000000000100001000000000100000

25:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1001 0000000000110101001011101110000000000000000000000000010010000000001000010000 1000010 01011000100110100110110010010000000000000000000010000010000 1001 00000000001101010010111011100000000000000000000000000100100000000010000100001000010000

26:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0101 0000000000110101001011101110000000000000000000000000010010000000001000010000 0100010 01011000100110100110110010010000000000000000000010000010000 0101 000000000011010100101110111000000000000000000000000001001000000000100001000001000100000

27:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1101 0000000000110101001011101110000000000000000000000000010010000000001000010000 1100010 01011000100110100110110010010000000000000000000010000010000 1101 000000000011010100101110111000000000000000000000000001001000000000100001000011000100000

28:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0011 0000000000110101001011101110000000000000000000000000010010000000001000010000 0010010 01011000100110100110110010010000000000000000000010000010000 0011 000000000011010100101110111000000000000000000000000001001000000000100001000000100100000

29:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1011 0000000000110101001011101110000000000000000000000000010010000000001000010000 1010010 01011000100110100110110010010000000000000000000010000010000 1011 000000000011010100101110111000000000000000000000000001001000000000100001000010100100000

30:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 0111 0000000000110101001011101110000000000000000000000000010010000000001000010000 0110010 01011000100110100110110010010000000000000000000010000010000 0111 000000000011010100101110111000000000000000000000000001001000000000100001000001100100000

31:11000100 11010011 01100100 10000000 00000000 00000100 00010000 - 1111 0000000000110101000111101110000000000000000000000000010010000000001000010000 1110011 01011000100110100110110010010000000000000000000010000010000 1111 000000000011010100011110111000000000000000000000000001001000000000100001000011100110000
« Last Edit: November 22, 2013, 03:14:15 am by Fusebox » Logged

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Dear All,

We are trying to reveres engineer the Mitsubishi Electric  Air con remote  to switch ON and OFF  from Arduino IR.  smiley
  Followd the  Chris as descried below.
http://wiki.crowe.co.nz/Mitsubishi%20Heat%20Pump.ashx

(Except the decode bit pattern on C# because we do not want all settings..just on /off).
So,we got the binary bit pattern. (89 bits 0 and 1 patern). On the bit pattern we do not know the timing of  High(1) and Low (0) singal.

So, we tried , X-SAT / NEC  protocol timing  ( for example 550 micor second ON /1100 micro second OFF)   for Sending . But NOT working even we match binary bit pattern of Mitsu remote. 

1. Is the carrier frequency of Mitsub is  38 KHz ?
2.  we have plan  to find the original timing with Oscilloscope  for ON /OFF

Any clue how to proceed ?  or Suggestion or Question?  smiley

With regards,
Chandra


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Well, that was easy... Protocol reverse engineering  : Solved.

The last byte is a CRC, and is calculated (addition) straight forward from byte 0 to byte 16, and truncated to 8 bit.

The pulse train is 145 bits long (with a logic "1" on the end), so 144 usable bits. Transmission is repeated once.

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Can you also share some schematics or code?
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