@derek-m same as the other guys. the samsung manual says quite clearly that its the slave. I didn't configure anything at the ESP end but I assume that it must be master by default, from what I google it can only be master. which makes sense.
@derek-m same as the other guys. the samsung manual says quite clearly that its the slave. I didn't configure anything at the ESP end but I assume that it must be master by default, from what I google it can only be master. which makes sense.
I'm pretty sure that is the standard setup, and it is the same set up for me, in my case mini PC running the python code is the master, Midea wired controller is the slave (as will be any future slaves I add in parallel eg room temperature sensors). The minimalmodbus code, which as I have already mentioned is remarkably well put together for python stuff, pretty much makes this explicit:
import minimalmodbus
instrument = minimalmodbus.Instrument('/dev/ttyUSB0', 1) # port name, slave address (in decimal)
A second slave might be kitchen_temp = minimalmodbus.Instrument('/dev/ttyUSB0', 2)
Midea 14kW (for now...) ASHP heating both building and DHW
@derek-m same as the other guys. the samsung manual says quite clearly that its the slave. I didn't configure anything at the ESP end but I assume that it must be master by default, from what I google it can only be master. which makes sense.
Is there Modbus communication between the heat pump controller and the heat pump, in which case one or other must have been designated the Master before ESP was connected. Does the Samsung manual mean that the heat pump is the slave to the controller?
this is samsungs modbus interface board. its an entirely separate board which all of us have bought and installed aftermarket into our heatpumps.
Its entirely independent of and separate from the connection between the heat pump and its "HMI" wall mounted controller with the pretty screen for changing the temperature etc.
so I've decided on my next step. steven's using an ESP32 module. I'm using an ESP8266 module as thats what I had in the right place at the time. 8266 is a bit less capable than 32, possibly in areas that matter, possibly not. anyway, to eliminate that as possible cause I'll rebuild it with an ESP32... I'm also hoping that this weekend is "ASHP weekend" i.e. when I cut the house over to the ASHP as heat source. There will now be a short pause in transmission whilst time for some plumbing and electronics is found....
this is samsungs modbus interface board. its an entirely separate board which all of us have bought and installed aftermarket into our heatpumps.
Its entirely independent of and separate from the connection between the heat pump and its "HMI" wall mounted controller with the pretty screen for changing the temperature etc.
Is there Modbus communication between the heat pump controller and the heat pump, in which case one or other must have been designated the Master before ESP was connected. Does the Samsung manual mean that the heat pump is the slave to the controller?
That got me thinking. I think it is more accurate to say the heat pump (ie the PCB in the outside box) is the true slave, and the wired controller is in effect just a junction box. This diagram sort of explains, with the upper dashed box being the main PCB in the outside box:
BTB, my slave number is 1 not 16, as the image suggests, and ignore the typo. The main outside box also has H1 and H2 connectors, the modbus connections. I suspect the H1/H2 terminals in the wired controller just relay whatever is coming from the main PCB via the ABXYE wires (apparently may be a sort of proprietary Midea modbus, so maybe the wired controller converts that to standard modbus):
PS not trying to hijack this thread, just hoping to establish some commonality/general principles.
@cathoderay it'd be interesting to compare the different way the mfr's do it. I don't quite follow your midea explanation sorry.
in the samsung case its as per my scruffy diagram below. top half is there on every samsung out there. thats the way the system works.
bottom part is entirely optional and what we're all doing.
Sorry, should have been clearer. Here's my setup in a rather unelegant image, but I hope at least clearer:
It's similar to the Samsung set up, but the H1 H2 modbus RS-485 cable comes off the wired controller ('HMI' device) rather than the outdoor unit, with (I think) the H1/H2 terminals in the wired controller just replicating what appears on the H1 H2 terminals on the outside PCB. Perhaps wired controller H1 H2 terminals are there for wiring convenience, it doesn't need another wire to be run to the outside unit.
Midea 14kW (for now...) ASHP heating both building and DHW
Hi, ive just installed my Samsung Gen 6 and in the process of tweaking the settings. Am I getting the right impression from this post, that there isnt any way to set up a schedule for heating, if I was inclined to want to?
My other question is the the heating(zone) mode displays 30 degrees, is this the thermostat set temperature? The only user manual I have isnt very user friendly, is that all there is (photo attached)?
Thanks in advance.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
welcome to the self-install club 🙂 do you have a strong feeling of achievement?
I have 5 manuals, including the modbus one. 2 are dupes though. some of the manuals were packaged inside the outdoor unit, only found once I opened the case for that part of the install, but I'm sure you'd have found them if you've self installed. they're all online so I was mostly working off those anyway.
what mode do you have the controller in - external stat vs internal and room temp (LWT based on WC) or fixed LWT control? what it displays will vary depending on that. I think if its showing 30C thats probably fixed LWT from what I remember when I worked my way through the modes. a certain amount of trial and error is needed. have you watched the various setup videos on youtube (graham hendra has some decent ones)?
I've not found anything useful (or in fact at all) for heating scheduling in the samsung controller, but I wasn't expecting to - I believe its generally acknowledged to be a bit pants in that respect, you need to add something else (3rd party like Homely , or a roll your own) to make it more sophisticated. maybe the wifi gateway and app can do something but I've not bothered with that so just speculating.
I'm using my evohome system (TRV's upstairs only , downstairs all one zone now) to schedule heating setback overnight, and warm bedrooms only when needed. evohome talks to home-assistant (with some node-red doing the logic), home assistant then sending "on" to the heatpump (though a relay) based on my control parameters and automation logic which I am still very much tinkering with.
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