I'm using OTGW since many years (2016) without issues.
Board: Opentherm Gateway Rev B, (c) 2012 - Schelte Bron
IC2: No Max232, direct serial -> USB converter in a USB-A plug
Pins 11-14 and 12-13 connected
I don't have any LEDs connected.
Still using OpenTherm Gateway 4.3 on the PIC16F88
otmonitor-6.5 on a Raspberry-3
In late summer, I had issues with General Heating got enabled despite the Thermostat Siemens QAA73 was manually set to hot water mode only, no heating.
When bypassing the OTGW-unit completely, this did not happen. With the OTGW-unit, General Heating got enabled, despite the Thermostat was still set to heating-off and ot-monitor was always configured as Monitor-only. I also saw occasional Error-03 going up; maybe ~5...10 per day. That did not happen when I started many years ago. I'll address those issues, once I could validate, the OTGW-HW works flawlessly again.
Anyway I removed the OTGW-unit before the heating period and have now time to check for the root cause there. I'm a bit afraid to get it in the loop again for now, would first like to exclude HW-issues which might damage my heating system.
I followed your Trouble Shooting page /w settings to Original & PIC16F88:
- Power supply: ok, 5V between pins 5 and 14 of IC1
- Opentherm interface: ok. Voltages and currents match, also /w the opto-coupler and X1/X2 connected back-to-back
- Serial interface also works. When power cycling the OTGW, get on the Log
15:36:39.270635 üOpenTherm Gateway 4.3
15:36:39.313313 Thermostat disconnected
What I do not get are the repeated messages (about once a second) as described in the trouble shooting page like
15:19:41.689448 R00000000 Read-Data Status: 00000000 00000000
Note: the OTGW is still on my lab table, i.e. not connected to neither thermostat nor the boiler.
- Issuing commands via ot-monitor works, e.g. this one
15:40:00.855969 Command: PR=B
15:40:00.906110 PR: B=14:30 07-01-2021
- I also measured the voltages on the pins for the PIC. They are all correct except for pin2 which is 0V instead of 4.6V !!!
As stated above, I'm a bit hesitating to put the OTGW into the loop w/o further validation there are no HW-issues which could damage our heating system.
- Do you need more input / details to narrow down the problem?
- Should I upgrade to the latest firmware 5.8 at this point in time?
I did hesitate in the past as there was a potential incompatibility announced /w Version 5.0.
- could the wrong value on pin2 above indicate an OTGW HW-issue?
- Is there a possibility to reset all settings of the OTGW to default values?
- Is there anything else I should consider
Thomas