Fitted the Salus RT500RF today, this wasn’t such a difficult job but I did blow two fuses following bad advice. The wiring of my Vaillant Turbomax doesn’t require bridging the COM and Live as suggested in many online videos, nor do I need to add a LOAD resistor between pins 4 and 5 on the boiler.
Here’s a simple diagram to demonstrate how to connect the Salus RT500RF to a Vaillant. Now simply when pins 3 & 4 of the Vaillant are bridged they will start the boiler up. An optional pipe thermostat to switch the boiler off if the pipe overheats can be inserted in between pins 3 on the Vaillant and N/O on the Salus RT500RF.
Now I’m getting ready to start sniffing the airwaves with my SDR and my RFM12B to see what I can do. All I really want is to set/get the current state of the boiler.
Thanks to impshum digging around with epic google foo I found the correct GPIO_BASE for the Raspberry Pi B2. Raspberry Pi used to have a peripheral base address of 0x20000000 now it’s 0x37000000 on the B2, so the GPIO peripheral address is 0x37200000 which has broken the odd GPIO based product (including the HotPi). I’ve added a pull request to RFM12B-Linux and that should be that. I still need to merge in changes for OOK and see if that works and of course, figure out how to set the frequency to listen/transmit on.
RFM12B’s will soon become a must add hardware to the Raspberry Pi, I just need to get that software working :). It’s a great piece of kit, and the code already in github is a good jumping off point. I’ve merged in a OOK sender fork, and I’ll be adding code to put the device into OOK listen mode. All of this controlled via ioctl. Essentially with the little RFM12B’s hooked directly into the Raspberry Pi GPIO port’s SPI pins you’ll have the ability to mess with anything out there, which uses 433/434MHz or 315MHz if you’re in the US, or 915MHz or 868MHz whatever HopeRF board matches with your locations radio standards.
At present I’m looking at getting the OWL to work because I already understand most of that. Next I’ll be looking at getting RF light sockets, lightwaveRF devices, indoor/outdoor weather sensors and even doorbells into the supported devices list.
I have an Owl energy monitor model CM160, which has been mostly just acting as a real time monitor. In order to really USE the device I’m going to need to connect it to one of my running computers. At first I was using Eagle OWL on github. However it requires me keeping the LCD receiver and I want to eventually get rid of that, mostly because the only useful thing about it, the thermometer isn’t accessible over USB.
I decided that I should start experimenting around the 434MHz band with my SDR’s and see what I could come up with. Continue reading →