Gateway Hardware Help

This Forum is about the Opentherm gateway (OTGW) from Schelte

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Ian.
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Gateway Hardware Help

Post by Ian. »

Hi All,

I have just built a Nodo-Shop Opentherm gateway V2.12 Wi-Fi version which I have a problem with and hope you can help me please.

With the Opentherm thermostat and boiler connected directly, the thermostat illuminates and operates, however, when I place the Gateway in circuit the thermostat is dead.

Going through the fault finding process on otgw.tlcode.com all the voltages check out until I come to the Serial Interface. The PIC was supplied programmed, however, OT Monitor is not logging a missing thermostat and when I send the "PR=B" command it returns:

13:30:10.274992 Command: PR=M
13:30:33.355915 Command: PR=B

With the PIC in place, the voltages on the pins are as per the attachment showing out of range readings.

Any Ideas?
Attachments
readings.JPG
readings.JPG (16.06 KiB) Viewed 4349 times
hvxl
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Re: Gateway Hardware Help

Post by hvxl »

All the readings in red are I/O ports. The values seem to indicate that the PIC is not running its regular program, which would configure those ports as outputs. The really strange one to me is pin #4. 3.92V is quite a bit higher than the 3.3V supply voltage.

My first impression is that the PIC is either damaged, doesn't get power, or doesn't have the right program. When you apply power to the OTGW, do leds A, B, C, and D flash once, followed by led B flashing once per second?

You say all the voltages in the power supply section check out. So you measured 3.3V on pins 5 and 14 of the PIC? All the pins of the socket have been soldered properly? You did place the PIC correctly in the socket? The right way around and all pins in their respective holes? At no point did you power up the OTGW with the PIC in a wrong position?

Sorry if these questions sound silly, but remote debugging can be quite challenging and I have to make sure that I correctly understand the situation.
Schelte
Ian.
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Re: Gateway Hardware Help

Post by Ian. »

Hi,

Sorry for the typo in the table, pin#4 should have read 3.29v.

I have reflowed all my joints and rechecked my voltages on the chip pins, but no change unfortunately.

I have not seen any of leds A,B,C & D illuminate at all, only the voltage leds have ever lit.

Yes I have 3.30v between pin# 4 & 5

I double checked the orientation of the base and chip before powering up.

Is it worth reprogramming the chip or do you thing its hardware related.

I've attached a couple of picture of the board for info.
Attachments
IMG_7887 (Medium).JPEG
IMG_7887 (Medium).JPEG (146.24 KiB) Viewed 4007 times
IMG_7886 (Medium).JPEG
IMG_7886 (Medium).JPEG (122.06 KiB) Viewed 4007 times
hvxl
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Re: Gateway Hardware Help

Post by hvxl »

Ian. wrote: Tue Feb 04, 2025 12:47 pm Is it worth reprogramming the chip or do you thing its hardware related.
Wait, does that imply that you have a PIC programmer? If so, it would be interesting to attempt to read the program from memory. That would confirm if the right program is loaded and that the PIC is functional.
Schelte
Ian.
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Re: Gateway Hardware Help

Post by Ian. »

I’ve ordered one from Amazon which should arrive tomorrow on the off chance that it would be needed.
Ian.
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Re: Gateway Hardware Help

Post by Ian. »

Well I bought a PIC K150 programmer which doesn't do the PIC16LF1847 - I/P.

Oh well, back to google to find one :-)
hvxl
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Re: Gateway Hardware Help

Post by hvxl »

With the right sketch on the Wemos, you can actually program the PIC without any additional hardware. This requires the V2.12 OTGW board and a PIC that was originally programmed with gateway firmware 6.6. I believe both are true in your case.

On the V2.12 board there are two jumpers, marked LVP. You have to add a blob of solder on both of those to connect two I/O pins of the Wemos to the ICSPDAT and ICSPCLK lines of the PIC. Then you need a special sketch on the Wemos. Problem is, I'm not quite done with that yet. :oops:
Schelte
Ian.
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Re: Gateway Hardware Help

Post by Ian. »

I’ve been in touch with Remco from nodo-shop and he is kindly sending me out another programmed PIC to see if that is the problem.
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