The last piece of missing hardware is finished. The picture below shows the 2nd RF to Zigbee gateway I had to make to be able to receive all the Hydronic balancing sensors I made earlier this week. One of those sensors just couldn’t make it through 3 walls all day long, so I created a temporary solution on a breadboard to solve this.
A very simple yet effective way (for me) to get the sensor data where I want it (in my Domotica system) with minimal effort.
The JeeNode acts as a RF receiver and just echoes everything with a valid CRC to the Digi XBee; from there it eventually arrives at my Zigbee Coordinator with which I can communicate over TCP/IP.
The JeeNode runs a slightly modified version of the RF12Demo sketch made by Jean-Claude Wippler. I used the NewSoftSerial library to create an additional Serial port, and added a few print statements for the XBee port, right there where the RF12Demo Serial.println()’s the received RF data to the Serial port. Compile, Upload, setting the RF band, group- and node ID and I’m done!
This JeeNode is powered by a 5V USB adapter and the XBee gets its power from the 3.3V JeeNode ports. The XBee uses a Zigbee End Device AT firmware (2864) with the Sleep Mode set to Pin Hibernate. But because pin 9 is wired to GND, this means that the XBee is permanently on. Only 3 wires are needed to connect the XBee to the JeeNode: 3.3V, GND and a JeeNode digital pin to the XBee DOUT.
That’s it – moving on with where this all started with: understanding the flow of heating energy in our house!
December 2nd, 2011 at 22:36
Hi,
I really appreciate your effort. I am thinking about Max! Cube as well.
I am in the stage ONE. I mean we are installing pipes and radiators etcetera…
I am studying possible solutions.
AFIK it looks the more appropritat is the “fhem”. see: http://fhem.de/fhem.html
By the way, I would like to know what do you mean by the terms “the Hydronic balancing sensors” and “Hydronic balancing”.
In my point of view: if you are not able to measure the hydronic pressure or hydronic fluid flow, it is, IMHO, not possible to talk about “Hydronic balancing” or about “Hydronic sensors” at all.
I like the idea to know the in/out temperatures on radiators. I think it is the best way to know the I/O temperatures during the day.
But I really do not understand, how it is connected with the hydronic flow or with the hydronic balancing.
An other question: do you know some other people interested about decoding the Max! Cube wireless protocol?
Regards
Petr
Regards
Petr
December 3rd, 2011 at 00:59
From what I have learned so far (it’s all still very new to me), there are several ways to apply hydronic balancing. Especially in an existing system it’s not that easy to enable flow measurements there where needed; another way to “do” hydronic balancing seems to be the so-called “Temperature method”. Basically, this means measuring the delta-T on all heat exchangers in a stationary condition of the central heating (=burning @ 100%) and changing those delta-T’s to the values needed. This method is often applied when the more accurate and preferred method of calculations based on the characteristics of all the central heating elements (central heating, piping, radiators, isolation, room volumes, etc.) cannot be used. So, IMHO, hydronic balancing can be done without flow measurements, although the margin of error will probably be larger. (10 vs. 20-30%)
No, I don’t know anyone working on or interested in decoding the MAX! Cube wireless protocol.
Question for you: why would you want to decode the MAX! Cube wireless protocol. For me, the Cube is a tool to completely open a valve, completely close a valve or set a temperature I want. What will the wireless protocol add to this?
December 4th, 2011 at 09:01
Hi Robert,
Can you share the code/sketch you are using an the hydronic balancing
project.
Thnx and kind regards
Jeroen
December 4th, 2011 at 12:00
Hi Jeroen,
Do you mean the code for this RFtoZigbee gateway, for the sensors or both?
December 4th, 2011 at 14:46
I would like to take a peek at the code for both setups.
Are you still going to make the Opentherm gateway ?
Ps:
Have you look at the option that Jaga provide called Dynamic Boost Effect
low temperature boosting ..
Greets
Jeroen
December 5th, 2011 at 00:54
OK, I’ll provide a download link tomorrow. But don’t expect too much, both sketches are no more than a quick&dirty modification of the RF12demo- and RoomNode-sketches which can be found on Jean Claude Wipplers website.
And yes, the Opentherm gateway will be made, cause I still think it will be useful to have. The use as monitoring device is enough for me to finish this gateway.
I haven’t looked at DBE yet; for now, I (want to) believe that I can achieve my goals without changing the hardware.
December 5th, 2011 at 08:47
Hi,
I’ve followed you work in decoding and using MAX in you home automation system and I wuold be interested in buying one.
However, is there any way to control the boiler only by the Max cube ? How does the boiler start when there is heat demand from a room where there is no thermostat? For ELV/Conrand there is FHT 8w relay that “starts” the bolier when needed. Is here something similar?
Thank you.
Catalin
December 5th, 2011 at 15:41
Hi Catalin,
No, there isn’t. The MAX! system cannot control the boiler; you’ll have to find some other solution for that.
December 5th, 2011 at 22:38
Here’s the link: http://www.hekkers.net/files/HBSensor.rar