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Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Thu Oct 22, 2015 10:17 am
by ThinkPad
Hi,
I got a OTGW from Digit a while ago. It works fine, but when i start it up, it presents itself as "OpenTherm gateway 2.0"... so it is really old when i see that on the OTGW website firmware 4.0 is available.
However my OTGW uses the older P16F628 + 4Mhz crystal so i can't upgrade to the newer firmwares meant for the 16F88 i guess...
Would it be possible to exchange the 16F628 for the newer 16F88 so i am up to date again? Or has the PCB / components also changed between the versions?
I don't mind a bit of soldering.
Re: Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Thu Oct 22, 2015 9:27 pm
by hvxl
The biggest problem is that the serial interface is on different pins on the two PICs. Pin 8 is TX on the 628, while it is RX on the 88. RX on the 628 is on pin 7 and TX on the 88 is on pin 11. You would have to shuffle those connections around. Other than that, there is nothing that I can think of off the top of my head that needs changing. Even though the boiler interface is different, it uses the same inputs and outputs. So that should still work together with a PIC16F88.
Clearly this is all purely theoretical, so I'm not giving any guarantees that it will actually work with the mentioned changes. But I give it a pretty good chance.
Re: Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Fri Oct 23, 2015 8:35 am
by ThinkPad
Good to know, thanks.
I'm not sure about exchanging the PIC, but first wanted to ask here
After all the only thing i do with it is monitoring the efficiency of my HR-boiler:
http://tweaken.blogspot.nl/2015/01/cv-k ... t-een.html which now works fine, i am only gathering data, for adjusting setpoint and such i have a Honeywell Round Connected Modulation (with app on smartphone).
Re: Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Fri Oct 23, 2015 4:31 pm
by ThinkPad
By the way, in Domoticz the OTGW says:
Code: Select all
2015-10-23 16:29:39.931 OTGW: OK
2015-10-23 16:29:39.931 OTGW: PF
Where does the 'PF' stand for? I couldn't find it on the OTGW website.
Re: Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Sat Oct 24, 2015 9:15 pm
by hvxl
As you're still using an old model gateway, you should get your information from
the old web site.
Re: Upgrading older OTGW by exchanging P16F628 for P16F88 ?
Posted: Mon Nov 02, 2015 12:07 pm
by ThinkPad
Thanks, didn't know about the existence of that version of the website.
I decided to buy a new PCB & PIC & some other components. The 'expensive' parts like the transformer can be used again, so i will desolder them from my old OTGW and reuse them, #savetheenvironment