piBridge Protocol

[gambrinus]

Is there any documentation on the RS485 data exchange protocol? We are creating a custom module and are considering various ways to send data to the RevPi. We would like to use the piBridge if possible, but a serial over USB connection is seeming like the simplest solution. We are utilizing the RevPi maker kit, and if the protocol isn't too difficult to work with, we would prefer to use the RS485 pins. Does this require a custom RAP file or recompiling the kernel?

Thanks in advance!

[edit]I should mention that the module in question will be utilizing an embedded Arduino chip. I just read that there is a duino driver for the RevPi, so it's looking more and more like USB might be the way to go.

[volker]

Hi,
the documentation is the source code on GitHub. And yes, the protocol is somehow complex as there is an initial state when piControl is collecting information about the physical order of modules and then does send the PiCtory configuration values to the modules. After this phase there is a cyclical poll of all registered modules. If you need any kind of event or message based communication you should not consider to use the PiBridge. In such a case we would recommend to take the new RevPi Connect and its ConBridge which does a a plain TTY based UART channel. For future developments this would make more sense although we have not yet planned to sell a ConBridge "maker kit" (which you would need to use because of a mechanically different coded Brdige connector. Please contact sales@kunbus.de if you would like to go that way.

[gambrinus]

Thanks Volker,
Is the RevPi Connect reverse compatible with RevPi core modules? Is there a blog post or other information I can read on the RevPi Connect?

[volker]

RevPi Connect does have different back plane busses on both sides: left side is legacy RevPi Core compatible IO modules and right side does offer SPI and UART without any other drivers but the Linux integrated ones. Thus it is perfect for any modules using transceivers and message/event based communication. We have show the new system on Hannover fair and we also already offer all kinds of different "Con" modules: Bluetooth (mixed mode classic and LE), M-Bus wireless, generic CAN, LoRa, ZigBee, TinyMesh (the wireless components will be available for all frequencies used in different countries). E.g. Our VHP (very high power, 169 MHz) version of MBUS does have a indicative LOS of 5 Km range.
Many more modules are planned and will be available the next years.
Connect is twice as wide (45 mm) and does have 1 Di and 1 Relays contact on board as well as a hardware watchdog circuit to offer a complete remote secure operation. The system is forced into cold start if this hardware chip does not get a reset every 60 seconds. Thus the watchdog reset could even be done on the highest possible layer (e.g. over the internet connection) to get the most secure proof of proper operation.
The 2 USB slots now can drive up to 1 A each and there is a second independent Ehternet connector to give you the best chance of isolating fieldbus traffic from WAN connections.
We do expect the shop launch in June.

[matt.s]

...we also already offer all kinds of different "Con" modules: Bluetooth (mixed mode classic and LE), ... generic CAN,

I was waiting for the Connect to build a system that uses bluetooth and CAN connections. I can't find the respective Con modules on the shop, are they released already? If not, when do you expect to make them availible?

[dirk]

Hi, I have moved the thread to the Hardware forum. So thank you for your interest in our new Con-Modules.
The ConM-Bus and the ConCan modules are released and will be produced during August. But the ConBluetooth
module is currently in development and not yet ready.

But if you want to have pre evaluation boards please just send a mail to our sales team at sales@kunbus.de .

[matt.s]

Hi Dirk,

I did send an email to sales@kunbus.de last thursday, but didn't receive a response so far. Is everbody on holidays or maybe it went to the SPAM folder?