RS485 Hub 3D draft

First 3D draft of the RS485 Hub. I have moved all connectors to left and top because it will be attractive to use this together with RPI 3B+ that have Ethernet/USB at right. As mentioned I could have used XPortHub for this, but I often need exactly RS485/Ethernet in higher density because RS485 is very attractive connecting to small, remote sensors/actuators. The drawback With what I do here is lack of galvanic isolation, but I will add a separate Hat for that purpose later. In an ideal world we would add galvanic isolation everywhere, but it comes at a huge size and performance cost (slower Serials), so it makes more sense to add isolation between nodes or then connecting to long wires or special Equipment.

  1. CAN Port 1
  2. CAN Port 2
  3. RS485 port 1
  4. RS485 port 2
  5. RS485 port 3
  6. SWD port
  7. RS485 port 4
  8. RS485 port 5
  9. RS485 port 6
  10. USB port
  11. Power Connector 5 external Power.
  12. 3.3V PSU
  13. Status Led’s – I admit I went a bit over the top here With 1 status for each RS485 and CAN. 
  14. 8 or 16Mhz Murata x-tal with capacitors.
  15. Serial Flash. I just added this because I had a spare SPI port.
  16. MCU
  17. RPI Connector. I basically use 5V and SPI pins on this Connector.
  18. Terminator jumper

The actual board will probably change a bit. I like doing these mock-up’s placing connectors and components, but as I start routing I also end up changing things to adapt. Schematics is done, so it will take me a few mornings to get routing done. I find PCB routing to be a relaxing mind game – so yes – this is my form for relaxing.

You probably feel the site have slowed down a bit, and yes it has. To much happening Real Life at the moment so it will be a bit like this for a while. It is also a consequence of me digging deeper into SW as I have an large backlog of things I need to code up.

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