SPI communication between boards

I'm working on a project where I want to be able to use the SPI bus and I2C to send data to 2 other boards, I've seen some people say that SPI is for communication on the same PCB then others say you can with long wires and need boosters. Now this as caused a bit of confusion.

So the 10way ribbon cable should be no more the 150mm away from the main board, Would this cause inference with the SPI orI2C signals ?

And is there any precautions I need to take ?

I've attached a picture just to show I intend on doing it if possible.

I2C is for on-board communication, SPI can bridge larger distances. 150mm ribbon cable should be okay for both.
You may need level shifters between the 3.3V ESP32 and 5V Arduinos.

Check whether the Arduino libraries support SPI slave mode. I2C (Wire lib) supports both master and slave mode.

Thanks for that, At the moment I have everything running all of one supply all ok which consists of 2 x SPI GLCD, 2 X MCP4822 12Bit DAC'S and 2 X MCP3426 16Bit ADC'S plus an PCF8574(but this will be running off the main board as there is only one), The same for the SPI GLCD'S will be running of the main board, So it's only the DAC'S and ADC'S that will be running through the isolators along with an isolated 5V supply one for each channel

I've not yet added the SI8630(3 Channel SPI isolator and the SI8600 I2C isolator's yet, I've got the SI8630 but waiting on the SI8600'S to arrive so I can try it before I lay out the PCB for them.

vague wiring diagram. how are the conductors organized?

DrDiettrich:
I2C is for on-board communication, SPI can bridge larger distances.

isn't it the other way around?

aarg:
isn't it the other way around?

No. See the clock rates which are higher for SPI, indicating less susceptible communication.

aarg:
vague wiring diagram. how are the conductors organized?

The diagram is just to show the distance between the boards really and just showing where I would have the connectors , I've not done the PCB yet as I was unsure about the distance. As to the power supply for the isolation I was thinking of using one of these RI3-0505S Isolated Module DC DC Converter 1 Output 5V 600mA 4.5V - 5.5V Input.
My idea is to get it all mocked up on some veroboard prototype PCB get it tested and then look at laying the PCB out for it carefully placing the components.
As to using the R13-0505s unit I'm not sure if to have in on the main PCB and then send the isolated 5V supply to the PCB or to have it on the Channel PCB and just send the 5V supply then carry out all the filtering and isolation on the channel PCB'S.
The other way I did think of doing it would be like a daisy chain like in the second diagram below (again 100-150 from the main PCB) but I think option 1 would better(the one above)

rem.JPG

rem.JPG