I’m new to the community, hope this is the right Category I use here.
I’m planning to make a 2 zone thermostat for my heating, and I would control it with OH (running on Pi4). The question is more about the relay.
So, I’ve already found some relays on the market (china), some with WIFI or with direct USB control.
Actually, I like the idea to control the relay with USB directly from my OH.
I’ve found two types of relay, direct USB and one with HID (driverless) mode.
However, what I’m unsure is that how will I (OH) send the command to the relay through USB?
I’ve checked and found that the commands are in HEX code, but still don’t see the big picture here.
What can you suggest or where could I learn more about this topic?
On the other hand, would you suggest wireless comunication instead?
Not really. I’m working with https://hestiapi.com/ which has all the hardware built in. It runs openHAB on an RPi 0 and I’m changing the openHAB configs to improve overall performance, particularly boot time (so far I’ve brought it from 25-30 minutes down to ten which is probably the limit). I’m no help for hardware beyond…
How do you send commands to the USB without openHAB? Is it a serial device? Then you would use the serial binding. If it needs special drivers you might be on your own and need to use the Exec binding to execute external scripts from OH to control it.
Depends on how far away the relays and sensors need to be from the controller and from each other. If you have two zones, you will almost certainly need to temp sensors feeding this thermostat and in order for both of them to be in their respective zones it might be too long to run wires.
Yes, I’ve already checked the serial binding add-on configuration, but I’m not sure which type of USB relay I’m better off with? Or it doesn’t matter wheter HID or not?
The distance is not a problem here. I ask the question in regards with feasability and stability. Do you or the community have more experience with let’s say a “sonoff wireless relay” or I should rather try the USB relay.
What I’m worried about is that if the wireless relay loses power, and coming back online, then the WIFI connection will not be restored automatically, as the relay will not store ssid and authentication details or am I wrong here?
Than what killed the devices was an EMP, not a typical power surge. And an EMP, depending on it’s strength and frequencies and all sorts of other variables can just as easily kill wired devices too. In fact in some cases the wire will act as an antennae which makes the wired devices more vulnerable than the wireless ones sometimes.
Lightning is a common source of EMP but the sun and accidents like exploding transformers or capacitors and such.