Remeha Calenta interface for Homeseer

[gdfde]

does really nobody knows where to purchase this recom interface cable for the quinta 25 Recom with ordering number 58.900 in an onlineshop.
I contacted remeha, but they just responded with a link to their homepage...i have also asked the austrian partner of remeha, but they don´t have it

Any hint is highly appreciated.

[haje]

This is my first post to this forum. I learned a lot from the valuable information in this forum. This helped me to write a little python script to read data from my Remeha Avanta heater. The script should work for other Remeha heaters too since it reads the configuration from the original Remeha xml files and a file called AvantaV1-P3-Request.xml. Please note that the script does not yet support multiple failures, it only views the first failure.

The python script reads data from a Remeha Avanta heater and writes it to standard output or a web server. The script requires pyserial to make a connection to the heater and cherrypy to view the data on the website. The data can be viewed via http://localhost:8080/tables after the webserver is started. To start the webserver execute: ReadData-v3.py -c all -w

My heater is connected to a mac via a serial to ethernet converter. This is why serial_for_url is used to connect the heater.

My Avanta heater always gives "out of range (max)" for the WW temp. The Recom software reports "open", which means out of range. I assume the Avanta does not have such sensor or the sensor in my heater is broken.

Python code.zip

Python code + xml file with request codes

(4.35 KiB) Downloaded 1070 times

[vanisher]

I did log some data because of the weird readings once in a while:

The R2_word is the hex value from the result_word:

Code: Select all

value_byte0 = Mid(data, 10, 1)
hex_value_byte0 = hex((asc(value_byte0)))

value_byte1 = Mid(data, 11, 1)
hex_value_byte1 = hex((asc(value_byte1)))

result_word = (hex_value_byte1 & hex_value_byte0)

The R2 is the converter hex value / 100:

Code: Select all

int_result = cint("&H"&result_word)/100

List of values:

Code: Select all

21-3-2012 23:42:36 ~!~COM5_DATA_R2_word~!~1554
21-3-2012 23:42:36 ~!~COM5_DATA_R2~!~54,6

21-3-2012 23:43:36 ~!~COM5_DATA_R2_word~!~1540
21-3-2012 23:43:36 ~!~COM5_DATA_R2~!~54,4

21-3-2012 23:44:36 ~!~COM5_DATA_R2_word~!~152C
21-3-2012 23:44:36 ~!~COM5_DATA_R2~!~54,2

21-3-2012 23:45:36 ~!~COM5_DATA_R2_word~!~15E
21-3-2012 23:45:36 ~!~COM5_DATA_R2~!~3,5

21-3-2012 23:46:36 ~!~COM5_DATA_R2_word~!~154
21-3-2012 23:46:36 ~!~COM5_DATA_R2~!~3,4

21-3-2012 23:47:36 ~!~COM5_DATA_R2_word~!~14F0
21-3-2012 23:47:36 ~!~COM5_DATA_R2~!~53,6

21-3-2012 23:48:36 ~!~COM5_DATA_R2_word~!~14E6
21-3-2012 23:48:36 ~!~COM5_DATA_R2~!~53,5

21-3-2012 23:49:36 ~!~COM5_DATA_R2_word~!~14C8
21-3-2012 23:49:36 ~!~COM5_DATA_R2~!~53,2

21-3-2012 23:50:36 ~!~COM5_DATA_R2_word~!~14B4
21-3-2012 23:50:36 ~!~COM5_DATA_R2~!~53

21-3-2012 23:51:36 ~!~COM5_DATA_R2_word~!~14AA
21-3-2012 23:51:36 ~!~COM5_DATA_R2~!~52,9

21-3-2012 23:52:36 ~!~COM5_DATA_R2_word~!~148C
21-3-2012 23:52:36 ~!~COM5_DATA_R2~!~52,6

21-3-2012 23:53:36 ~!~COM5_DATA_R2_word~!~1482
21-3-2012 23:53:36 ~!~COM5_DATA_R2~!~52,5

21-3-2012 23:54:36 ~!~COM5_DATA_R2_word~!~1464
21-3-2012 23:54:36 ~!~COM5_DATA_R2~!~52,2

21-3-2012 23:55:36 ~!~COM5_DATA_R2_word~!~145A
21-3-2012 23:55:36 ~!~COM5_DATA_R2~!~52,1

21-3-2012 23:56:36 ~!~COM5_DATA_R2_word~!~1446
21-3-2012 23:56:36 ~!~COM5_DATA_R2~!~51,9

21-3-2012 23:57:36 ~!~COM5_DATA_R2_word~!~143C
21-3-2012 23:57:36 ~!~COM5_DATA_R2~!~51,8

21-3-2012 23:58:36 ~!~COM5_DATA_R2_word~!~141E
21-3-2012 23:58:36 ~!~COM5_DATA_R2~!~51,5

21-3-2012 23:59:36 ~!~COM5_DATA_R2_word~!~14A
21-3-2012 23:59:36 ~!~COM5_DATA_R2~!~3,3

22-3-2012 0:00:36 ~!~COM5_DATA_R2_word~!~140
22-3-2012 0:00:36 ~!~COM5_DATA_R2~!~3,2

22-3-2012 0:01:36 ~!~COM5_DATA_R2_word~!~13F6
22-3-2012 0:01:36 ~!~COM5_DATA_R2~!~51,1

22-3-2012 0:02:36 ~!~COM5_DATA_R2_word~!~13CE
22-3-2012 0:02:36 ~!~COM5_DATA_R2~!~50,7

22-3-2012 0:03:36 ~!~COM5_DATA_R2_word~!~13C4
22-3-2012 0:03:36 ~!~COM5_DATA_R2~!~50,6

22-3-2012 0:04:36 ~!~COM5_DATA_R2_word~!~13B1
22-3-2012 0:04:36 ~!~COM5_DATA_R2~!~50,41

Somehow some hex values only consist of 3 characters.

Edit:

Ow, found it!

The second part of the hex code:

Code: Select all

value_byte1 = Mid(data, 11, 1)
hex_value_byte1 = hex((asc(value_byte1)))

Strips a leading zero.

So when for example the r2_word is 154, it should be hext 1504
Question is, how to fix this.

[Digit]

Normally when you need leading zero's, you do something like right("00" & stringvalue, 2) or use a formatting function like .ToString("X2").
Depending on the language you use.

[vanisher]

it's vb homeseer uses i'll guess..

What do i have to change to use the ToString ?

Code: Select all

value_byte0 = Mid(data, 72, 1)
hex_value_byte0 = hex((asc(value_byte0)))

In the code above the hex_value_byte0 is missing a leading 0 once in a while.

[Digit]

Try hex_value_byte0 = right("00" & hex((asc(value_byte0))),2)
This takes the 2 most-right characters: "01" stays "01", but "1" becomes "01"

[vanisher]

Thx! That does the trick. No more weird values from the Calenta.

[erichlm]

With the help of this forum and Robert's blog I soldered a USB to Remeha Calenta cable and am able to read all the information into Homeseer with the scripts.

Now I want to be able to change the room temperature set point. I played with the vb code a bit but I must admit this is a bit too much for my limited knowledge. I used the datagram the heater sends back when querying for the temperature and sent it to the heater. This doesn't seem to do much.

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hs.SendToComPort (7, CHR(02) & CHR(10) & CHR(10) & CHR(02) & CHR(74) & CHR(00) & CHR(00) & CHR(00) & CHR(00) & CHR(20) & CHR(00) & CHR(00) & CHR(00) & CHR(00) & CHR(00) & CHR(171) & CHR(03))

Is this even the right way to do it or am I on the wrong track? Any directions will be appreciated

[Digit]

Hi erichlm,

I've got bad News for you; you're on the wrong track.
This is a read-only interface; you can send requests and the Calenta will return the information requested, nothing more.
No setpoint here...

I would advise you to have a look at the OpenTherm interfaces that are discussed on this forum or maybe look at an Ethernet enabled thermostat, or maybe Z-Wave, all depending on what fits your skills/budget/home automation system best.

[erichlm]

Thank Robert, that will save me a lot of time. Would have been nice for a 12 euro solution.

[bus147]

Hi all,

on jan 28 this year I already asked this question in this topic. But since I never got an answer and it's getting colder, I'm asking again. Or does anybody know how to contact forum member menno?

tia

Hi all,

first post here. Thank you for sharing all the Remeha information and plans.
With regard to the initial post, I've some observations and questions about the plan and pictures.

The final interface has four ports, but the schematic one shows two of them. Power and the remaha signal.
There's a switch on the interface which also isn't present in the schematic.


Does anybody have a complete plan?
What's the function of the switch?
Could anybody post a picture of the inside of the fully assembled interface?


Thanks

[Digit]

I think menno must have missed your post.
Maybe he'll see it now..

[bus147]

Hi Robert,

so you don't know either... I tried to ask the same question on your blog but the topic was closed for comments. And compliments to you for your blog.

[Menno]

In the first post, you can see were the switch is used for

quote: The interface I build has also a switch on it. With this switch I can use the external input on the thermostat (Isense). This external input is connected to my digital I/O board that I use for several purposes. (this I/O board is also connected to Homeseer)

The two ports that you see on the picture are for connecting the external Isense-input and for connecting my I/O-board to it. The external Isense-input can be programmed on the Isens thermostat as setting the thermostat to ECO-mode or some other setting you would like (see Isense documentation for that).

[Digit]

Hi Robert,
so you don't know either... I tried to ask the same question on your blog but the topic was closed for comments. And compliments to you for your blog.

Thanks, and no I didn't but now I do, just like you