Normally, connecting a new device means more cables. And I want everything connected to my LAN (or WAN), so I need to convert the RS-232 to Ethernet somewhere.
Although I have Ethernet near the Calenta, that single cable I have over there is being used by my HA7Net, which takes care of counting the hot water usage with a 1-Wire DS2423 counter and measuring the Temperatures of the 5 floor heating groups. So that’s a no go; I can’t use that cable without adding another switch; and I don’t want to, for just 2 Ethernet connections.
Then I realised I still have an unused RFXCOM RS-232 module, and it’s put inside a RFXCOM LAN Interface that’s right above my head (between the ceiling and the roof, that is). This RS232 module was once used for one of my Sony EVI-D30 PTZ cameras with VISCA-protocol, but since this cam has been replaced with a fixed one I don’t actively use this RS-232 module anymore. This saves me a RS-232 to Ethernet converter with another power adapter…
So now I had to find a way to get the cable from the Calenta to this LAN Interface. Getting a 4-core flat phone cable through 2 narrow holes in 30 cm thick walls which are already populated with a bunch of other cables is no fun, but after a few hours I managed to get it through without damaging anything. Pffew..
Now it’s time to get the MAX3232 from the breadboard into an enclosure. I was thinking of creating something like this:
Add a few capacitors, wires, female DB9 connector, a small box and I’m done; and that’s what I’m working on right now. The fact that I’m not able to connect the Remeha directly to my PC anymore (to test the new interface) doesn’t really bother me anymore; I’ve seen enough comparisons of results of my Domotica system and the Remeha Recom software (which needs a COM port) that I’m confident enough that I won’t need Recom anymore to check things; and if I do, I can always use an 32-bit XP machine and a virtual COM port driver for that… it’s time to Ethernet-enable my Calenta and move on!