Mystery optical(?) connector - Page 1
Forum section: electronics / general

author: grumpydoc
author_rank: Super Contributor
timestamp: December 21, 2017, 11:03:53 pm
content: Long shot, not least because I only have a terrible photo of said connector.I own a house in which the central heating is based on an air-source heat pump. Wouldn't have been my first choice but it came with the building and works well enough that I have no desire to rip it out. I would, however, like to be able to control it remotely.According to the manual the controller - a Stiebel WPMW 2 - has an optical RS232 interface but other than that I cannot find anything out about it.Stiebel sell a box which provides a web interface but it is not cheap at £640 (that's trade price, so without VAT, and possibly not sold to individuals). It appears to hook into the bus between the controller and the heat pump itself (interestingly this appear to be a CAN bus) - Googling around there appears to be a small amount of effort into hacking the CAN bus interface and one guy who found the wired RS232 interface on his heat pump (different model to mine though) and wrote some python scripts to interface to it but that's it.I haven't asked Stiebel but as they have a product that competes with what I would want to do and, AFAICS, have stopped selling the optical cable/converter to hook up to a PC I would be mildly surprised if they told me much of anything useful. I did find a forum post mentioning a price of €180 for the PC interface which is pretty steep.The first problem is identifying the connector - which is shown in this photoHas anyone any idea on what the connector might be? Or any experience with these controllers?I'm reluctant to take apart the working controller - more hassle than I have time for - but they occasionally turn up on eBay at sensible prices so hopefully I can get one to take apart and look properly at the thing.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 21, 2017, 11:09:51 pm
content: Unlikely to be anything standard - probably just a proprietory shaped hole, with a phototransistor/IR LED

author: grumpydoc
author_rank: Super Contributor
timestamp: December 21, 2017, 11:32:58 pm
content: Quote from: mikeselectricstuff on December 21, 2017, 11:09:51 pmYeah - you just know the set up will provide maximum annoyance.Presumably it has to be bidirectional, but I'm not sure I see how. I'm more hoping someone on the forum knows something about these units than is able to recognise the connector, if I am honest.I'm nowhere near the kit at the moment - will get chance for a further look over Xmas.

author: abraxa
author_rank: Frequent Contributor
timestamp: December 22, 2017, 08:05:37 am
content: The good news:The bad news: the guy never shared his circuit. However, he did say that his circuit is a copy ofhttp://openv.wikispaces.com/Bauanleitung+LAN-Ethernetand he uses a MAX232 that he connects to IN/OUT so that he can talk to this device via RS232. You could of course also directly attach an FTDI to talk USB. The optical interface is a SFH7221-Z.Software: He says you can download ComfortSoft 3.5.0 v-52 athttp://www.stiebel-eltron.nl/vakpartners/vakinformatie/downloads/comsoft-software/or you can use an alternative software fromhttp://www.kromschroeder.de/Downloadbereich.4101.0.html(4.2.0 Rev.1068). Kromschroeder is the manufacturer of the device that Stiebel-Eltron is rebranding.Summary thread for the protocol:http://www.haustechnikdialog.de/Forum/t/168379/Stiebel-Eltron-WPF-per-Konsole-auslesen-und-Parameter-aendernOriginal thread with complete discussion:http://www.haustechnikdialog.de/Forum/t/98046/Defekte-Stiebel-Eltron-WPF-7-mit-Waermepumpenmanager-WPM-II-wiederbeleben-und-einbauen?page=3Circuit side discussion:https://www.mikrocontroller.net/topic/252033It's all in German, so if there's a particular part where you have issues translating, let me know.

author: grumpydoc
author_rank: Super Contributor
timestamp: December 22, 2017, 08:35:47 am
content: Quote from: abraxa on December 22, 2017, 08:05:37 amWow, thanks that is a really good set of pointers.I can't quite see how the optical interface works from those shots, I suspect all would be clear if I had a spare unit to inspect.

author: abraxa
author_rank: Frequent Contributor
timestamp: December 22, 2017, 08:56:55 am
content: QuoteYeah, it's a real shame the guy didn't publish his circuit. I really, really don't get why he didn't. However, he did post a close-up of the unpopulated PCB that he's using () and with the picture above, it should be straightforward to deduce the circuit since we know which parts he's using. My assumption is that the extra parts he's added (diodes) are used to do away with the MAX232 and produce RS232 line levels without the converter IC.btw, apparently the optical serial interface uses the following settings:Baud 2400Data Bits 8Parity evenStop Bits 2

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 22, 2017, 09:50:45 am
content: Opto part looks a similar package to thishttps://www.digikey.co.uk/product-detail/en/marktech-optoelectronics/MTRS6140D/1125-1062-ND/2798928Orhttps://uk.rs-online.com/web/p/reflective-optical-sensors/4550975/I'd think probably most likely infrared, and phototransistor rather than photodiode

author: grumpydoc
author_rank: Super Contributor
timestamp: December 22, 2017, 02:02:04 pm
content: Quote from: mikeselectricstuff on December 22, 2017, 09:50:45 amSo,.....How would you make a bidirectional link - where I have (a tiny amount of) experience with optical it has been either network connections where there is one fibre for transmit and one for receive or SPDIF which is, obviously, unidirectional.I am aware of bidirectional fibres but they are wavelength multiplexed.Ah-ha! penny drops, electrical connection out to sensor on end of cable at controller, optical only over last mm or so. D'oh

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 22, 2017, 02:03:11 pm
content: And half-duplex, obviously.

author: grumpydoc
author_rank: Super Contributor
timestamp: December 25, 2017, 12:49:49 pm
content: Picked a controller up on eBay for 20€, dead from a "power surge" so maybe fixable but no great loss if not - no idea whether these have a small SMPS or just a capacitive dropper (although the fact that the RS232 is opto isolatedmightsuggest that the circuit is not mains isolated).

author: grumpydoc
author_rank: Super Contributor
timestamp: January 06, 2018, 06:38:52 pm
content: My "dead" unit turned up today. Don't know how dead yet as I've had time to take it apart but not to turn it onMike was right, just a hole above an IR diode/phototransistor - the device looks like aSFH 7221Steibel confirmed they do not sell the cable any more so DIY is the only option. They don't have the software either and, so far, the links above are dead. That probably is no great loss as I'll want to use a Pi or something similar for the interface.Two board construction. Small linear PSU, 80C32 MPU, 4153 RTC with 0.1F supercap and 81C91 CAN bus controller are the main points of interest.EDIT: Software is athttp://www.kromschroeder.de/heizwaerme/produkte/downloadbereich.htmlEDIT2: Just noticed this is a WPM controller, not WPM2; doesn't really matter for this use. It also appears to work - at least the MPU and user interface stuff, remarkably this isafteran unfortunate experience with 240V and the CAN bus VCC rail.. Note to self, when feeding mains into unlabelled PCB which has a LOT of spade connectors to choose from double check that the orientation of the board matches the orientation of the detached rear panel with the labels on

author: mzutg
author_rank: Newbie
timestamp: May 04, 2018, 09:40:41 pm
content: Hi,did you have any luck connecting to the board?Best

author: grumpydoc
author_rank: Super Contributor
timestamp: May 06, 2018, 06:30:30 am
content: Not yet - haven't had any time to look at it.

author: fredmoro
author_rank: Newbie
timestamp: October 26, 2020, 11:20:51 pm
content: Helloo!I have a WPL 18 Cool heatpump, with WPM II controller. And I think I could communicate with it, using the optical interface.I use a raspberry pi, and an IR LED + photodiuode connected to the pi serial uart. The photodiode and the IR LED salvaged from an old ball mouse. The optical elements are too big to fit in the hole, so I used optic fibers to connect them to the wpm ii. Soon will post some photo of it ...So it semms working - I'm trying to read all the info gathered on this forum, and the links above... Now I can read some response on the serial port, but don't know what they mean...Do you have any progress?

author: amyk
author_rank: Super Contributor
timestamp: October 27, 2020, 12:19:14 am
content: I wouldn't call that a connector so much as it is a hole with a sensor in it.

author: fredmoro
author_rank: Newbie
timestamp: November 09, 2020, 11:54:00 am
content: Hi.I tested the communication: The messages were just reflections or something ... So I read my own message back in a distorted way. (you probably need some other component in the circuit, like a capacitor or something)In the meantime, I have found a successor to SFH 7221, which is still available: SFH 7250https://media.osram.info/media/resource/hires/osram-dam-2496516/SFH%207250.pdfI think I’ll buy some and continue experimenting with them. This will at least ensure IR compatibility with WPM II

author: grumpydoc
author_rank: Super Contributor
timestamp: November 21, 2020, 09:47:34 pm
content: IsupposeI really ought to find more time for this projectIt's almost 3 years since I started - sadly I have essentially zero time for hobby electronics these days.As it happens I found a WPMII at a reasonable price on eBay which rekindled interest - rather different board based on a µPD78F1168Quote from: fredmoro on November 09, 2020, 11:54:00 amYeah, it sounds like there are reflections meaning your phototransistor is picking up output from your IR LED - but none of the other circuits (see below) include anything to suppress "local echoes" so, presumably, if you get the two SHF7221/7250's close enough together and well aligned it is not a problem.Sadly several of the pages referenced a couple of years ago no longer exist - though the web archive has a partial record, including this pagehttps://web.archive.org/web/20160619033006/http://openv.wikispaces.com/Adapter+Eigenbau.The last but one is probably pretty similar to the hardware previously discussed in this thread but the last one is also interesting - utilising a USB interface but the TTL-level RS232/SFH7221 interface side of things is very simple.As a starting point I reverse engineered the schematic for the WPM controller I bought (I chose to do that board because the serial I/O is on fixed pins on the 80C32 microcontroller so it was easier to start at those pins).The red dots are where there are odd vias that I have not been able to trace. They usually start out on a trace on the top of the board but don't connect on the bottom of the board (it is 4-layer) and the ground fill prevents me from seeing if there is a trace going somewhere on an inner layer but it's quite possible that theydon'tgo anywhere - the circuit seems complete without adding anything.The enable is one of the data outputs from a 74HC4094 serial->parallel shift register, I assume this is just driven by the controller, I haven't bothered tracing it further.So, next step is to figure out what else I need to buy, apart from a £1 SFH7250, to make minimum order at Mouser

author: alyy
author_rank: Newbie
timestamp: November 04, 2023, 10:29:58 pm
content: Hey hey grumpydoc, any progress here?I am on the very similar project, trying to link WPMW to ESP32 -> wifi -> mqtt server -> remote management.

author: geggi1
author_rank: Frequent Contributor
timestamp: November 07, 2023, 05:24:10 pm
content: Assuming you the inteface is very similar what used on fluke scoopmeters.You can google "fluke scopemeter optic interface diy"You can use a USB to serial converter at TTL level and a few additional componets to build the interface.

author: grumpydoc
author_rank: Super Contributor
timestamp: November 08, 2023, 05:57:30 pm
content: Quote from: alyy on November 04, 2023, 10:29:58 pmSadly not - mostly because I decided against leaving a connected PC, plus router, Livebox etc running 24/7 when we were not in the house.

author: alyy
author_rank: Newbie
timestamp: December 11, 2023, 09:43:12 pm
content: I made some progressBuilt a crude IR RTX device using SFH 7250, diode, 2 resistors and USB-UART (TTL) cable. It works!Found original software somewhere deep in the internet archives.Quite a few curse-words while installing software made in XP & Vista times onto Win10 machine.But, at the end, I got it up and running! Software connects to the heat pump, reads data and config is possible.Now I have collected a few samples of communication using a com port sniffer.Next task is analyze the data and build a small controller board using ESP32 to read statuses, temperatures and select operation modes.Task a bit further down the line is MQTT or Home-Assistant integration.

author: alyy
author_rank: Newbie
timestamp: December 22, 2023, 11:59:20 am
content: If anyone needs more information on this topic, I was able to build a simple optical interface and windows software that reads parameters from the Stiebel Eltron and compatible heat pumps. Tested on WPM2.My GitHub project

author: Clubazur
author_rank: Newbie
timestamp: February 21, 2024, 09:27:21 pm
content: Hi alyy,Great work. I am a pretty good Home Assistant user and I would like to integrate my SE WPM. Unfortunatly I am on the beginning road to integrate this. First step, can you please give me a clue where to find the ComfortSoft 3.5 Software?AFAK, all Legacy links are dead now. Plan is to use esphome / MQTT and custom esp32 infrared Interface. Maybe you can help me for this first step.Thanks

author: alyy
author_rank: Newbie
timestamp: February 22, 2024, 06:03:01 pm
content: Hi, thanks for interest in my work.It would be great if you can test my project from the Github. Link is above andhere. It has all the essentials of the ComfortSoft in a small package. Also great for diagnosing the cable and connectivity to the WPM control box.When you get this up and running, I can share my copy of the ComfortSoft together with instructions on how to install it onto the modern Windows machine. It originates from the Win XP eraDo you have WPM or WPM2 control box?Do you already have the IR cable?I like your idea to use ESPHome as a bridge between HA and UART port. I am not yet familiar with both of them, so my question is, how and where do you plan to encode and decode data packets for the heat pump? Will that be a custom code in the ESP or in HA? How do you make visuals for such a custom device in HA?I currently don't have the HA yet, therefore I am running my monitoring software on a tiny PC in the boiler roomPlan is to migrate to HA at some point..

author: Clubazur
author_rank: Newbie
timestamp: February 23, 2024, 04:21:08 pm
content: Hi alyy,I don't have an IR cable yet. If you can share a schema, or give me an hint where to buy, would be great. I have to find out first more about the protocol and how "heavy" it is. Plan is to decode this on a ESP32 device (c/arduino on PlatformIO), first step will be a MQTT sensor device for Home Assistant. But first I need the cable. I have an WPF 13 (2003!) running with the IR option in front of the controller.Thanks.

author: alyy
author_rank: Newbie
timestamp: February 23, 2024, 05:54:48 pm
content: I made a diagram for the cable and posted it into the github repository.Protocol is pretty simple, if you pull down my source code (in Pascal / Delphi) it is pretty easy to convert it to C code. I made it as modular as possible.In short, it's a data packet of fixed length. Containing sender and receiver address, r/w command, heating circuit number, register address, value and checksum. Comm is UART, 2400, 8, E, 2. Send one packet out with request and receive one packet back.You need a list of parameters that you are interested in reading or writing, procedure to pack and unpack the data structure and UART port.p.s. There is another person, also from France, that is building something similar. Also my plan is to buy RPi in the nearby future, install HA and migrate this heat pump to it. So we are 3 people working towards the same goal. I think we should set-up a common place for this development. GitHub seems appropriate place for that. What are your thoughts?

author: Clubazur
author_rank: Newbie
timestamp: February 24, 2024, 03:48:58 pm
content: Great. I will setup my cable in the next few days. If I succeed I will take a closer look, what we can do. First I will try your Software as is.Thanks

author: Eltron
author_rank: Newbie
timestamp: March 02, 2024, 06:50:22 pm
content: Hi Alyy,A WPL33 and a WPMWII were installed 2005. I bought a device called DCo-aktiv GSM wich connected to the bus and converted to RS232 and the Comsoft SW.I could connect a modem or PC. I was interested and used it for a few years. Now I am 73 years old and would like to use it again, because the WP gives errors. Unfortunately I only rescued one file „ComSoft.exe“ wich is not enough to run the SW. It obviously needs some DLL to install. I am not familiar with GitHub and pascal/Delphi and HA. I would highly appreciate your help and share your copy of the ComfortSoft together with instructions on how to install it onto w10.Thank you very much.

author: alyy
author_rank: Newbie
timestamp: March 02, 2024, 07:25:09 pm
content: Quote from: Eltron on March 02, 2024, 06:50:22 pmHi. First check that you have connectivity with the (new) computer. If your PC doesn't have RS232 port, you need additional cable RS-232 to USB. And install drivers for it.If you are lucky, this device will have same communication protocol as the optical cable on the WPM2.My software can read all errors from the WPM2 and also has included error descriptions. With ComfortSoft I got only error codes without any description.Using my software is very simple. Download the .exe file fromthis linkand run it. No installation needed.You can access error descriptions directly on the WPM2 unit in the Commissioning menu. Access code is "1000".For ComfortSoft software - I will upload it to a file sharing service and will send you link in the private message.Let us know the progress.

author: alyy
author_rank: Newbie
timestamp: March 03, 2024, 08:48:36 am
content: I am reading the manual supplied together with ComfortSoft. It shows device called "CoCo PC active". Attached. Is this the box you have?You can try setting the switches into two different positions, Service or Installation mode. And check which mode gives you better connectivity to my software and to ComfortSoft.Here is the link to my copy of the ComfortSoft version 4.2 that I was able to find in the depths of the internet archives.https://www.dropbox.com/scl/fi/njgo065n2m144aink21g9/ComfortSoft_420_1068.zip?rlkey=sxnzced6c7mhfo3ryd5asbqj7&dl=1Read the Readme.txt file supplied in the zip archive for instructions for installation.

author: Eltron
author_rank: Newbie
timestamp: March 03, 2024, 07:50:30 pm
content: my box is fron 2005. i will test tomorrow. thanks..

author: Eltron
author_rank: Newbie
timestamp: March 03, 2024, 08:05:50 pm
content: the sw i was using was called ComSoft vers. 3.5.x stiebel eltron branded.

author: alyy
author_rank: Newbie
timestamp: March 05, 2024, 01:34:44 pm
content: Quote from: Eltron on March 03, 2024, 08:05:50 pmAs far as I understand, Stiebel Eltron software is exactly the same, difference is only in brand logo and text. Because original software was rebranded.

author: alyy
author_rank: Newbie
timestamp: April 22, 2024, 11:14:47 am
content: Anyone any progress on this topic?