Advanced Search

Funny thing is, the Mesa 7c81 and a stacked RPi look like a more compact solution.

NVME would be nice, the RPi5 with a NVME drive is blazingly fast.


Did you stick with the Mesa fpga pin to 7c81 layout ? Or did you change it to make routing easier ?

If you change things around, especially the clock signal, the SPI_CLK for comms is a little tricky to work out to begin with.

Sorry don't mean to add feature creep, man I wish I could design a simple board for the KSZ8851 Ethernet chip for my mesa clone thingy. So hats off to you Old Chap.

I have this one, used on my mill with a PC platform: Expensive
Planar Pct 2235 22" 1920X1080 Full HD Touch Screen VGA HDMI DISPLAY PORT USB

For the RPi5: Cheap
www.ebay.com.au/itm/225953008741

I would assume if the touchscreen interface is USB you should be fine. Tho the raspberry pi forums maybe a better resource, just look\ask for usb hid compatible touchscreen, stipulate USB HID is the only option.

The serial steppers are nice because they are easy to setup and they are also very quiet. I dont know if there is an fpga firmware for it thought. The SPI ones, someone has done a custom firmware to work with those.

What is W13 doing? Is it just for swapping between the usb or the green connector?
Consider adding a jumper that can disconnect power to the FPGA or separate the 5v rail between FPGA and RPi5. I found it convenient having a separate jumper for that, incase you needed to either separate the power between the 2, or if you need to reset the MCU/FPGA, you dont need to turn off the RPi

When you are done will you post the design on that easyeda website so I can clone it to modify it? Im also hesitant about a 1 board thing, but I wanted to make something with a swappable MCU/FPGA , and the formfactor looks pretty decent sized.

Thank you guys for the interest and the suggestions! I will try to respond to a few of them here:

"I have occasionally thought that there should be a niche for a similar board, but with on-board stepper drivers (Trinamic or some other serially-controlled driver)
That would, of course, need a dedicated HAL driver, but those can be surprisingly straightforward."

I was actually planing on designing a seperate IO Board featuring the Trinamic 5160 Drivers, as they would allow me to run high current stepper motors. They come with UART and SPI interface functionality but I haven't really seen an advantage in interfacing them serially. Maybe someone has a good argument as to why it would be worth it to go through the integration troubles?

"I like having the boards seperate, just in case my butter fingers cause one the voltage translation chips to blow a smoke valve and damage the PCB."

That was my thought process as well. I'm a little hesitant to put everything on one big PCB, as i feel like that would make errors more catastrophic. I also like the modularity of having seperate PCBs, especially in these early prototyping stages. I did actually bring the JTAG out, but realize that better labeling was neccesary, which I've since added.

"I am liking the look of this board. Did you do this in easyeda?
Suggestion, add the rpi 40pin header. Aside from being able to add stuff rpi side, I find it valuable for debugging the MCU/FPGA side of the board using a regular rpi without having to keep removing a cm module and you can use it as a backup incase you damage the 100pin hirose connectors or theres another RPi/chip shortage"

Yes, I did do this in EasyEDA. I started the project with EasyEDA becuase I foud the integration with the JLCPCB services appealing.
Including the 40pin Header is a great idea, which I will definitly add. Unfortunatly that will require major rerouting. Before rerouting everything I will continue collecting and thinking about additions/optimizations. That way I'll hopefully save money on design itereations.


I'd love to here if you guys have any other sugestions. The design philosophy behind this board is to make it the Compute Module 5 version of the Mesa Electronics 7c81, and I will probably finish this project making exactly that but I'm also open to brainstorming other ideas for potential future projects.

Thank you everybody!

I'm also designed a mesa clone for a Raspberry Pi, currently in the process of testing everything.
Except for the reversed Sserial Pinout it looks like I got everything right.
You can take a look at my schematic for reference: github.com/jstjst/stmbl-fpga-master/blob...tmbl-fpga-master.pdf
Be careful the SPI In Out labels in the 7c81 schematic are reversed compared to the ucf file. Luckily I could fix that in the ucf file.
I routed some signals under the fpga, I see no problem with it. But try to have no completely hidden tracks so you can fix them if you got some connections wrong. In my opinion one of the more important things is the placement of the decoupling caps.

There are some pitfalls with the whole (fpga) programming (especially when using the Ethernet host interface). But with some reading through the forum I got everything pieced together, including recompiling mesaflash and linuxcnc. So it is totally doable (for reference, this is my first deep dive into linuxcnc and mesa/hostmot2, only used the RPi GPIO interface before, didn't use/own a mesa card).

Big thanks to Peter for providing the schematics and all the information that is on the forum!

This setup is for sale.

Best,  Gene

Hello, I have gotten Linuxcnc running in my RPi 5 with MESA and am now moving on to cutting chips the original build uses a 10" Raspberry pi touchscreen (this: Cool hood 10.1 RPi screen), but I can't get the touchscreen part working. In the meantime I realize that 10" is small and I'd love to use the Probe Basic interface which required Full HD (1920*1080).

​​​​QUestion is: what touchscreen in 12-15" size have been proven working with a RPi 5? 

I am interested in the Waveshare 13.3inch DSI LCD ( Waveshare ) as it seems to fit from compact dimensions and have drivers for bookworm. I see these are dependent on kernel though so I am now fearful it may not work with our RT kernels? 

Any experience or other recommendation? 

​​​​​​Thanks!

Was thinking about this today.......Very interested

I am liking the look of this board. Did you do this in easyeda?

Suggestion, add the rpi 40pin header. Aside from being able to add stuff rpi side, I find it valuable for debugging the MCU/FPGA side of the board using a regular rpi without having to keep removing a cm module and you can use it as a backup incase you damage the 100pin hirose connectors or theres another RPi/chip shortage

What a fizzer. after days of talking it up, sending us home, cancelling freight services and public transport, Alfred headed north away from us and degenerated into a tropical low in the last hour or so.

Youtube seems to enforce a 12 hour streaming limit so I had to change the URL a few times when it timed out.  Then I found a weather setting so its still up!
www.youtube.com/live/KwGRpF-Cvp8?si=mQuM5AUsBVTC3fVe

Notes on the tech:
My Reolink doorbell camera is managed by a Synology NAS with a bunch of other cameras (10 all up). Synology Surveilance Station allows you to stream to YouTube so it was an interesting learning curve if nothing else. The Reolink is my only wifi camera because it was impossible to get a network cable to it. Instead, I tucked a 24v power supply under the tiles above the door and used the existing wiring to power the camera. There is a chime unit which plugs into a power point inside. (I still have the horrors when I remember running 24 network cables through a 2 story house 12 years ago). I have a PoE switch in the ceiling space for the cameras mounted in the eaves.

The Synology also connects the cameras to Home Assistant running on a Raspberry Pi 4b powered by a PoE hat. That is another story.

I recently retired my first Synology NAS after about 12 years. I had replaced 2 out of 5 x 3 Tb hotswappable drives in it in the last couple of years. I replaced it with another Synology with 2 x 16 Tb mirrored drives as the number of cameras overpowed the old NAS. Sold the old one for $450 AUD!

Thanks again. Initially I plan to do this using a Raspberry Pi using software stepping through GPIO, so I am a bit concerned about the Pi being able to keep up with encoder pulses. If it doesn't work on just the Pi, I will get a 7C81 Mesa board for it, but want to try using just the Pi first.

I don't ever see needing to use the spindle as a dividing head. I have a 4th axis on my mill if I need that, so I think two encoders, one for index and one for pulses would work okay for what I need. We will see.

Looking at your picture, that is almost exactly what I was picturing for the slot sensor mounting. I may try a 3d printed slot wheel. We'll see if it flys apart, but I generally don't run too high speeds and think it will be fine. I'll print it at 100% infill and make an aluminum hub to sanwich behind the pulley.

What brought this about is that the threading nut setup on the lathe broke last time I needed to thread a part and I figured it was time to convert to CNC. I plan to include 2 MPG handwheels mounted on the carriage so that I can mimick a manual machine for times when I just want to do simple turning. I have that worked out on the Pi already. I use a handheld wireless MPG on my mill but am thinking about adding 3 handweels and eliminating the wireless MPG. I've had a few loss of connection issues with it in the past.

This is a long term project so things won't happen too fast. I have access to a friends 13" Clausing lathe if I need one and he is only about 3minutes away. I have another big project I'm working on and this one is a fill in for times when I need a break from that one. Thinking about the basic X-Z conversion, the Z axis looks like a piece of cake, and if that 12mm ballscrew I got fits, the X axis cross slide won't be too bad either.

Thanks again.

Or you can follow this post

forum.linuxcnc.org/9-installing-linuxcnc...-4-5?start=10#320967

Simple Mesa Setup



Thanks to PWC

You definitely do not want DHCP and you do
need to set a static address.

You might try this:
DO NOT set a gateway or nameservers

I checked that thread and I haven't seen anything to address the Sync manager Watchdog.

Check this thread forum.linuxcnc.org/ethercat/54965-stepperonline-a6-servo maybe there is a solution