Multi channel timer/scheduler needed

Hi all

Long time OEM user looking for suggestions of a multi channel timer/scheduler to control charging of my diy powerwall, ground source heat pump (Seperate heating, hot water, towel rail schedules) and a few other things.

We installed the GSHP around 5 years ago, previously used a really cheap ASHP.
This is currently controlled by a Click PLC with an arduino connected via modbus to read temperatures. It works reliably but is far from ideal as changing schedules involves editing the PLC program.

We’ve had grid tied PV for 3 years now, just a small 2.5KW array split between 2 roofs but these are at a low pitch 15 deg and are essentually useless in the winter.

In august with the prospect of ludicrus energy costs for the winter i added 6KW of ground mounted PV (used ex solar farm panels), 2 growatt off grid inverters (SPF5000 ES) and built a diy powerwall with a Nissan NV200 24 KWh battery.
This is all up and running now although far from what i would consider a completed install. I plan to relocate the inverter to the garage so nothing is currently cable managed.
We had a really good start to october with only a few days where ne needed any grid power, then last week the weather turned and the 20+ KWh a day PV production turned into 5 KWh.

With this i looked around again for energy tarrif’s, we’ve just switched to octopus and had a smart meter installed 10th oct.
Since we don’t have an EV the GO tarrifs are unavailable to us, so i’ve just moved us to Agile Octopus (different rate every 30 mins published the evening before).
With this i need to be able to control the GSHP and what it is heating as well as charging the battery at the cheapest/lowest carbon times each day.

So i need a timing solution with 4 or more channels each capable of multiple on/off times a day that can be programmed/set in a few mins as it will be adjusted every day during winter.

It must not require a cloud to run although cloud integration to allow remote adjustment would be nice.

I’m open to software or hardware based solutions, ideally not Rpi based.

I do have a small pc running proxmox with emoncms, pihole and a few other things running so a local cloud is an option.

Spent the last few evenings searching for solutions and nothing suitable has been found, in my mind something that resembles MS Project with time along the X axis and the channels down the Y, where you insert and move around bars to signify ON times would be perfect.

Thanks Steve


I expect someone will be along to suggest Home Assistant and outline how to set it up. From my question for a slightly different requirement at RPi Home Automation Software HA seems to have several experienced fans on here.

I’m currently using domoticz which is smaller and simpler, and has timers attached to things as standard, but has fewer plugins available, so it depends how you can talk to your GSHP and battery controls, which I don’t think you’ve mentioned? (or maybe I am too dim to realise that it’s obvious from a “Click PLC with an arduino” and “growatt off grid inverters”).

If they support MQTT with Autodiscovery, it should be a fairly easy setup in several controller software. The timer interface is very much a list of on/off instructions, not a chart to draw bars on, though. I find it easy enough to set up some timers quickly, but I’m not sure I’d want to do it every day. My ASHP control, which varies every day, is decided by an event script, reacting to temperature sensor events. It doesn’t react to Agile energy prices yet because I’m not on that tariff, as I think the way the Energy Price Guarantee has been implemented makes Economy 7 slightly cheaper for our needs.

I’m sure I saw a chart interface timer while looking for a control I liked. Maybe I’m thinking of GitHub - ioBroker/ioBroker.scheduler: Create and manage schedule profiles. for ioBroker (I deleted my ioBroker test for other reasons, so I can’t check in practice), or maybe it was one of the many add-ons for Home Assistant… if Home Assistant, I hope someone will mention it.

Thanks for the suggestion.

I am aware of home assistant but to be honest i’m not really a fan of home automation or of having to rely on pc’s to control stuff. Especially when the stuff they are controlling could cause issues or even worse cost me money using grid power at the wrong time.

Ideally i would like a dedicated piece of hardware with relay outputs that i can interface with everything and a local web gui for setting times.

Non of the things i want to control are natively supposed to be controlled externally.

The cheap smart plugs i ordered as a temporary solution arrived, they are HBN branded but are Tuya based and pair just fine with Tuya’s app.
It seems as long as i download a schedule to them whilst internet access is present they will happily turn on and off to that schedule without internet. That was my main concern about anything cloud based.

Now i’ve confirmed Tuya devices will operate offline (at least for the duration of their programmed schedule), i think i can cope with the hassle of setting their schedule for now.
I’ve ordered a 4 relay Tuya board and if that works the same that will do whilst i sort the rest of the system. If cloud reliance becomes an issue it appears possible to host a local Tuya cloud within home assistant.

Whilst i would prefer something a little more convenient to set the schedule, i have many hours/days of work ahead integrating external control into the things i need to schedule.
The inverters will have to be fooled into battery charging from grid by emulating a battery management system on the can bus input telling the inverters the state of charge is low then switching to a high state of charge to stop grid charging.
The heat pump is already managed by the PLC so i need to modify the program for external inputs to control the operating mode.