OTG and Arduino

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

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Kong
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OTG and Arduino

Post by Kong »

Hi,

I'm not sure if I'm in the correct forum, let me know if not.
I've build Schelte's OTG, but instead of a PIC I'm using an Arduino.
Reason: I'm building my own home domotic system, all Arduino (MEGA).
I know Arduino, I want to stay with one microcontroller.
The 'controlling lights, smoke and burglar-alarm' part is more or less ready, now I'm focussing on the heating system.

My first plan was to use on/off thermostats, but then I have to use extra thermistors for measuring room temperatures.
OpenTherm is communicating the actual roomtemperature now and then, so no need for extra thermistors.

The plan:
Designing a PCB with:
- 6 thermostat connections
- 2 boiler connections (1 on/off, 1 OT)
- 6 output connections for controlling the resp. heating groups.
- mounting an Arduino MEGA (upside down) on the pcb.
I think 6 is enough for an average house.

The 'problem':
I'm quite new in designing double layer pcb's, It's almost impossible to make a single layer pcb.
What also could be a problem -challenge!-, is monitoring 6 instead of 1 thermostat. We'll find out later...

The questions:
- I understand that what i'm doing is very specific, but maybe there are other people interested in joining, especially someone with experience in designing and producing pcb's.
- For now I've a couple of Remeha QSense thermostats, but maybe in the future I want to use OT 3.0 thermostats (with backlight). Backlight is not working at the moment, has someone (Schelte?) worked this already out? Would be nice to implement on the pcb (I think it's hardware related, not software).
hvxl
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Re: OTG and Arduino

Post by hvxl »

Backlight is working with firmware 4.0 of the gateway. It didn't require any hardware modifications. The higher power is achieved by switching to the high level for the current (and optionally also for the voltage) during the idle period, instead of the default low levels for both. This raises the power levels from 40mW (5V, 8mA) to 90mW (5V, 18mA) or 306mW (17V, 18mA).
Schelte
Kong
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Joined: Fri Jul 25, 2014 10:56 am

Re: OTG and Arduino

Post by Kong »

Ah, thanks for that! I'll try that out.

Another thing: Has someone got the latest overview of all parameters? The latest version I've got is 2.3, but I wonder if there's a newer version available.
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