So, we have an old heat bed for our plants in the green house.
Since we live in Sweden the risk for below freezing is high until the end of May.
Our old heat bed is just an arduino with tree ds18b20 and two SSR’s.
One set of ds18b20 and SSR controls the heating, with a target temperature, a hysteresis and pwm as configuration.
The other set controls a fan, yes during the days it can get warm in there…
The last ds18b20 is just for the temperature out in the green house.
All temperatures are logged with a max and min which can ber reset.
The Mrs. wants two more beds…
I don’t want to struggle with buttons, displays and to much carving in boxes.
So, can I create a module that does this and can it run stand alone without Home Assistant isn’t running?
My thoughts is just to use HA as a gui.
Look into the bang bang component.
You set a high point and low point.
It would automatically control heater and fans to keep between those points.
How are your fans and heaters controlled,?
Yep quite possible - I have a standalone proofing box built using ESPHome and a couple of modules, some sensors and a heater. It can connect to HA for monitoring and control but doesn’t need to…
@Dilbert66: Thank you for the links!
Irrigation will be the next thing!
There I’m thinking of setting a watering type,
1 litres over a period 5 litres between 23,00 and 03.00 (knowing the flow of course)
2 just on between times
I have all the valves (12V) and even manifolds for the valves. This is yet another stalled project.
But that’s for the summer the beds are more urgent!
@samnewman86: Sensor 1 is in the soil, when this one reaches the set temperature, say 11°C it turns off the heating. It will be off until it reacher under the set temperature minus hysteresis, so if the hysteresis is 3°C it will heat again when the sensor goes under 8°C.
The fan is the oposite, it will start when sensor 2 is over for example 25°C and stop when it goes under the set temperature minus its hysteresis.
This works very well with my old controller, but I want to “step it up”.
Anyway I need to make a complete stand alone version as well for my cousin, he does not have HA…
The bang bang component looks like the one I’m looking for.
I will need two in one ESP, one for the heating and one for the fan.
The second sensor is in the air within the beds tent.
The third sensor is just to log the temperature in the green house.
Since I have two types of ESP8266, one with external antenna, I need a program to meassure the maximum distance difference between them!
I think the ones with internal antenna chould work, but I’m not sure.
The cell phones works like a charm in the green house. And they can even see my network in the middle of the lake, like 300-400 meters away. I think the phones are the weak link here… Cool!
I don’t want to work now, I want to go home and do som testing. But that has to wait for the evening
I’m not finnished, but there is some progress!
I managed to get the on board LED to react .
And then I made an automation that toggles the LED every second second.
For what use? -To meassure how far it reaches.
North of the house it was just some 20 meters.
To the south, no problems reaching inside the green house!
Slipped on the snow, slippers is not the thing to wear in snow…
But thinking of it, it must have been roaming problems. I have one Ubiquiti AP on the south and one on north side of the house.
I will create one node with the external antenna, just for comparison.
So far this looks great!
So I can see it on the node? I know I can see the strength in HA.
But on the node.
It is not for exact placing, it is just curiosity to see the differens between extarna and internal antenna. And of course the limits I have.
But the conclusion, so far, is that I don’t need external antennas in the green house
So I believe that on my property there is only need for internal antennas.
Progress! One of the heating beds are running, not finnished, but running. One thing about the Bang bang controller, I can’t set a temperature below 10°C. Is it some kind of undocumented to set it? And how vill this work if I connect a pressure sensor for controlling my water pump? This is a 3-phase 4kW that today has an ordinary pressure switch. By controlling it via the sensor, I can detect leakage, remotely control start and stop pressures.
