Design files availability?

[kaklik]

Hello,

are there original PCB design files somewhere? E.g. KiCAD schematics or complete project file? I need to change the position and type of connectors used. Also, I want to replace electromagnetic relays by solid-state switches to increase reliability.

Thanks

[samuk]

I would also like these if possible.

[samuk]

Any news?

[ZoltanPerhacs]

It seems that it uses the same hardware as the Cheap Heat Pump Controller.
You can find the schematic there.
https://github.com/gonzho000/chpc

[kaklik]

It seems that it uses the same hardware as the Cheap Heat Pump Controller. You can find the schematic there. https://github.com/gonzho000/chpc

Hi, it seems to be an important point. But unfortunately, the chpc repository is a simple folder full of bitmap images. Therefore it does not provide a step into the future of the open-source design of heat pumps.

[ZoltanPerhacs]

It seems that it uses the same hardware as the Cheap Heat Pump Controller. You can find the schematic there. https://github.com/gonzho000/chpc

Hi, it seems to be an important point. But unfortunately, the chpc repository is a simple folder full of bitmap images. Therefore it does not provide a step into the future of the open-source design of heat pumps.

Yes, full of bitmaps... like this repo... :)
But there is a pdf with the schematic.
Not a huge task to put it into KiCAD... and design a custom PCB or replicate this PCB made by Valden.

[samuk]

Admitting this repo is useless and starting again is probably required.

I think Jpearce the author of this page https://www.appropedia.org/Pumps_for_Peace has a PhD student starting work soon, so they may be able to help organise, although I don't expect they will be able to do the PCB design.

If starting from scratch I'd be in favour of basing it on https://www.sparkfun.com/micromod#processor_boards and providing a reference implementation using one of them, the Teensy perhaps.

I wonder if a Micromod carrier with UEXT exists? It might be possible to use https://www.olimex.com/Products/Modules/IO/MOD-IO/open-source-hardware

Or alternatively if the code would run on a ESP32 https://www.olimex.com/Products/IoT/ESP32/ESP32-EVB/open-source-hardware then a UEXT cable between the two modules

[kaklik]

Ok, that seems like starting the project from a scratch is necessary. But it reveals the usual questions:

• Is the current architecture still worthwhile to use or is better to redesign it?
• Are there some points of compatibility that should be preserved?

I am generally able to make PCB design work, but I am unable to code and maintain the required firmware. Related to the HW I have some idea of how it should be designed to be durable and has long service use without maintenance. For example is needed to avoid screwed terminals, electromechanical contact relays, etc. Of course, this requirement increases the price, which probably not everyone will accept.
Generally, we use a workflow where the prototype is made from MLAB modules. Then is extensively tested in several units. After that, the application PCB is designed, from each module design made by KiCAD.

[samuk]

Whether to redesign or not is a good question.

I'd be inclined to go with software compatibility at least for a first iteration. The 'OpenHeatPump' code seems to have more features than the older 'CheapHeatPump' https://www.diffchecker.com/8kxiqY6X/

I agree that longevity is desirable. I wonder if it's worth using "screwed terminals, electromechanical contact relays" in initial prototypes and then developing more robust solutions once we have a working prototype?

I'd not heard of MLAB before, it looks nice. Are there any standard(s) defined by it for GPIO beyond power? I've looked at this page https://wiki.mlab.cz/doku.php?id=en:rules but it only defines power pins? The only reason I ask (which is slightly off topic) is I've been kicking around an idea for a stacking dev board with 2x 40 pin headers

If I developed the baseboard, maybe the inputs and other peripherals for this project could be a daughterboard to that? It could connect via UEXT to either

a) This open hardware 4x relay actuator
or
b) Your more expensive 4x actuator