7i92H

Guys, I'd like to hear your opinions.

I have a 7i92H and would like to build something very compact with reasonable performance. What do you recommend using, a Raspberry Pi4, Pi5, or even a mini PC?

Ingo

I would not recommend the PI4 unless you already have it. It's a bit slow and requires
fussing to get a 1 KHz servo thread over Ethernet. The PI5 is much more capable.

 MiniPCs are normally fine though if they have RealTek Ethernet hardware you will likely
need the DKMS (manufacturers) driver as the built in kernel driver has latency issues.

A Raspberry Pi has its own I/O pins (albeit limited to 3.3V); connection via ethernet seems a bit stupid.


 

That is horribly bad advice. When using the GPIO pins on an RPi you require a base & servo thread, as you would with a PC with a Parallel port. Using a Mesa Ethernet card, in the case of OP, or a Mesa SPI card you only require a servo thread.
I use a RPi5 with a Mesa 7i92 & 7i76(plus some other smart serial cards) and I am very happy with it.

Yes the RPi5 requires an external PSU (does that really need to be mentioned ?) but some mini PC's require an external as well. Lenovo is one brand that comes to mind, I think the power blocks are similar to the Laptop power blocks.

Thin Clients may also be an option HP T630 are not so expensive on the second hand market and have a Quad core CPU,
www.parkytowers.me.uk/thin/hp/t630/

As an addendum to the above post, I'm working on a new Raspberry Pi image, suitable for both the 4 & 5 based on the raspios, that has all the nice setup features of a standard raspios image.

I'm hoping to create both a Bookworm & Trixie image.

"Yes the RPi5 requires an external PSU (does that really need to be mentioned ?) but some mini PC's require an external as well. Lenovo is one brand that comes to mind, I think the power blocks are similar to the Laptop power blocks."

Yep, I have at least 5 or 6 different MiniPCs around here for LinuxCNC testing and general use and none are
line operated, they all have laptop like power dongles (either 12 or 19.5V)

The RPi-400 may also be a solution, it's clocked a little bit faster that a RPi-4.
The new RPi-500, whilst a little $$$ does have a NVMe slot built. From experience the RPi5 is quite snappy with a NVMe drive.

"Yep, I have at least 5 or 6 different MiniPCs around here for LinuxCNC testing and general use and none are
line operated, they all have laptop like power dongles (either 12 or 19.5V) "

I thought I had too many PCs & RPi's for testing purposes, but think I might be a little below par.

tommylight wrote:

..... connection via ethernet seems a bit stupid.
Now why the hell would you say that ???
And, just in case, do not say "SPI is.... " as it is not.

You sticking up for the RPi now ?

Sorry to the OP for derailing the thread, but the Ethernet comment really needs to be addressed.

Actually the RPi5 seems to handle longer cables better than the RPi4. Only noticed when bench testing my Frankenstien boards.

Ethernet is definitely the go.