Opentherm Gateway

[jeroenc]

Nice "neologisme": automagically!

1million dollar question: did everything which needs to come online automatically, do so, or did you have to use your commander-in-chief authority and force them back online?

[Digit]

Well we have these kind of "tests" twice a year or so.. NUON and a Bosch microwave oven help a lot!
All I had to do was replacing a switch (10 minutes ago) and now everything is up and running again!
Zigbee, ELV MAX, 1 RFXCOM receiver and Touchscreen were down the whole afternoon because of the switch; the rest was OK and still is.

[MarQuez]

Hi Guys,

I want to ask if someone already made a plugin so the gateway can be controlled on the Vera?

[raymonvdm]

I`m currently building the gateway but have a issue with R8. The shoppinglist on http://tclcode.com/opentherm/schematic.html#layout states 1k2 Ohm but the schema states 1k5 Ohm.

Wich one do i need ? I orderded 1k2 Ohm

[hvxl]

I'm currently building the gateway but have a issue with R8. [...] Wich one do i need ?

I would start with 1k2. The resistor value should be chosen in such a way that the delays on OK1A for a low-to-high transition and a high-to-low transition are as close to each other as possible. In my measurements the optimum value was somewhere between 1k2 and 1k5. But I also found that it is safer to be on the low side than to exceed the perfect value. That's why I changed the value in the parts list to 1k2. However, there's quite a bit of leeway defined in the Opentherm specification, so either value will probably work just fine.

I should probably update the schematic to avoid confusion.

[raymonvdm]

Ok, i will go for the 1k2 I`m now waiting for the programmed pic and need to solder the comport and al should be ready to go

[Bwired]

Al
I created a forum for the OTG
So if you have a new question, please start a new topic and dont follow up this one.
You might have seen that i splitted up some postings
This all makes everything surrounding the otg much easier to find
Thanks Pieter

[Freemann]

never mind....

[wjhos]

Hi, i am new to this forum. I was interested in the Remeha gateway to connect to my new Tzerra 39 to be able to read outside temperatures. However that would set me some € 129,- back just to do that. Because i am planning to install a second Tzerra 39 to be able to control work and living area of my house seperately, that would be improportional. The gateway discussed in this forum caught my attention. However, it is mentioned that an outdoor sensor can be hooked up to the gateway, there is no concrete information :
which io pin, ntc, PT100 what value, do i have to change the software, and does the outside temp. appear on the iSense ? etc. can anyone help me out.

[hvxl]

The firmware doesn't currently have built-in support for any type of temperature sensor. I didn't need this functionality myself, and there are just too many types of temperature sensors to support them all. The idea was that someone who had a need for this functionality would hook up a sensor to one of the GPIO pins and add the appropriate support to the firmware.

Unfortunately it seems I didn't study the P16F88 datasheet close enough when it comes to analog input ports. I jumped to the conclusion that AN0-AN6 were RA0-RA6, which would mean that one of the GPIO pins could be used as an analog input. However, upon reexamination, I now see that AN5 and AN6 are RB6 and RB7. So, if you need an analog input (for a ptc or ntc), you would have to sacrifice (or move) one of the LEDs.

Another option (the one I would probably choose) is to use a digital temperature sensor like the DS18S20. This device can be connected to one of the GPIO pins and (with the appropriate firmware modifications) would give accurate readings without any need for calibration.

As I understand the iSense documentation, it should be possible to display the outside temperature. But I don't have an iSense thermostat myself, so I can't say for sure.

[raymonvdm]

The DS18S20 is available for arround 5 euro, i`m using one of them on a Fibaro Z-Wave module

Why should someone use a sensor on the gateway when there are also inputs on the boiler itself ? I know my boiler supports one but i`m using an RFXcom based one with the HomeSeer OTG plugin

[wjhos]

Some boilers have, some dont. Remeha Avanta and Tzerra dont have an input. However, the sell a gateway (but dont realy support it), to connect an outdoor sensor to. I was triggerd by this website http://www.tclcode.com/opentherm/index.html, but i cannot find the proper software and obviously there is no analog input for a sensor. Reading the site it seems that it is working with a Avanta boiler and also reading outside temps. How?

[hvxl]

Reading the site it seems that it is working with a Avanta boiler and also reading outside temps. How?

The outside temperature is obtained by my home automation system and sent to the opentherm gateway via the OT serial command once a minute.

[chipje]

I can't get my Otg to work . I only see messages coming from my thermostat.
When I run the Delay symmetrytest from the diagnose software, I get an error on OK1a going from high to low.
I've checked the opentherm interfaces as discribed, but nothing seems to be wrong.

Can someone help me out.

regards,
henk.

[hvxl]

If the interface checks all look good, but the symmetry test reports an error, the transition must be too slow. The most likely cause is a wrong value of R8. It should be 1k5 (black, green, red). Make sure you didn't mix it up with R10 (black, green, orange) - a subtle difference.