LinuxCNC raspberry pi - Microcontroller to do realtime stuff

Hello All,

Total newbie here with regards to Linuxcnc so the question might be naive or covered elsewhere.

From what I can gather the favoured equipment to do the realtime hard grunt stuff seems to be based around some form of Mesa card. Is there information on why an FPGA is considered best option to go for.

Best regards
nick

Simple reason is the Mesa boards are made to do one thing, and they do that very good, while RPI is made to do a lot of things and does non of them good ! But it is small !

Thanks Tommylight,

Does the Mesa card output pulses , bitstreams, etc that can't be handled by a low-cost microcontroller.

I'm interested in running LinuxCNC on a raspi and see the favoured option is to use a mesa card connected via ethernet (i think), the limitation with this is raspi v3 and lower doesn't have an ethernet port that can provide realtime output.

Could another option be to connect a microcontroller via I2C or SPI to the PI.

Thanks
Nick

Having looked at the Mesa 7C81 manual , it connects via SPI to a PI so all looks very good.

nickom44 wrote: Thanks Tommylight,

Does the Mesa card output pulses , bitstreams, etc that can't be handled by a low-cost microcontroller.

I'm interested in running LinuxCNC on a raspi and see the favoured option is to use a mesa card connected via ethernet (i think), the limitation with this is raspi v3 and lower doesn't have an ethernet port that can provide realtime output.

Could another option be to connect a microcontroller via I2C or SPI to the PI.

Thanks
Nick

Mesa and PiDiCnc have boards that connect to RPI3 through SPI:
Mesa 7c80 <<< do check if this is correct
PididCnc 3805 for steppers

Also if you a are not married to the RPI idea, you could use a OrangePI
that has a built in independent microcontroller that can handle real-time tasks:

forum.linuxcnc.org/18-computer/39037-linuxcnc-orange-pi#167290