BsbGateway - serial port + Web Interface

[fred-c1]

Hello Johannes,

I am planning to try our software on a Raspberry pi 3B+ Can I use a serial port (UART) connected to a USB port? If you have some time, I think it would help to add a (some?) screenshot of the web interface in order to understand the capabilities.

Thanks, Fred

[loehnertj]

Yes, you can use an USB-RS232 (actually I am doing the same).

Thanks for the hint about screenshots, I will see if I can find time for this.

[fred-c1]

OK: I was looking in bsb_comm.py (1st time I see a Python file...) Looking at config.py everything is now clear. Just 1 question regarding avoiding collision (by monitoring CTS signal of the serial port): How critical is this? Strongly recommended? My main concern would be corrupting the parameters of my heat pump. Is there a risk?

[loehnertj]

Not critical at all probably. In the discussions that I read so far, nobody else seemed to care about collision avoidance. I am not even sure how well it actually works (not owning a logic analyzer...) I think the worst that could happen is that messages get lost every now and then.

[strubbi77]

Hi, do you think it possible to use https://adapter.ebusd.eu/index.en.html together with your Code? Difference is 2400 Baud vs. 4800 Baud. And logical 1 and 0 are different.

Best regards Thomas

[loehnertj]

Hi Thomas, depends on what you want to do exactly.

A. Connecting to an eBUS device (what the adapter is intended for) - 100% no. eBUS and BSB are two different "languages" and bsbgateway definitely does not understand the eBUS protocol.

B. Out-of-spec use to connect to a BSB device: 50% no.

• Voltage levels and electrical sending part might actually work, from what I read from the circuit schematic
• Baud rate 4800, parity and stop bit must match exactly to the BSB specs. I don't know any of the ICs used in the circuit, so this may be the showstopper, if the board does its own digital processing.
• I didn't check how eBUS peers are supposed to handle collisions compared to BSB. But I would guess that one could get away with just ignoring the problem.
• Lastly, the RPi interface of your board seems to communicate via SPI. bsbgateway currently only has a driver for standard RS232 (serial) interfaces. SPI communication is possible in RPi/python, but somebody :-) would have to program a driver module for it analogous to serial_source.py.

If "B" is what you're aiming for, the developer(s) of the board should be able to answer those questions with much more certainty than me.

Edit: Apparently the main IC is an 8-bit microcontroller. I.e. the board is like a miniature computer. So it is most likely also "no" for "B".

[strubbi77]

Hi Johannes,

thanks for your input. It would be B, so the Out-of-Spec usage of the eBUS <-> USB device. Or at least the base design. Modifying the code or configuring a USB-driver would be easier for me than building the board for the communication from scratch. So for me it's a point of which aproach (<60€) brings me to the goal with the highest success rate.

Edit: I've checked the specs for the rightmost IC (PIC16F15356-I/SO): (https://4donline.ihs.com/images/VipMasterIC/IC/MCHP/MCHP-S-A0002813954/MCHP-S-A0002813954-1.pdf?hkey=6D3A4C79FDBF58556ACFDE234799DDF0)

I'll ask the developers from the board to be sure.