To whom it might concern, I've tested all thermistors, endstops and heaters with no problems.
Only untested parts are the stepper drivers, they'll run as standalone or external drivers for now.
No SPI or UART-config so far.
This is the other info I was thinking of, from a 1980s system with separate, analog servo drives.
The lookahead / PID is probably easier to replicate from this version:
That's the CNC section of this overall drive system diagram:
The control those diagrams relate to (Heidenhain TNC360) runs everything on a 16MHz MC68000 if I remember correctly, for machines operating with multi-axis interpolation and contouring at accuracies down to microns, but with totally separate servo drives.
Does anyone make a processor with A-cores, M-cores, and CAN_FD?
Not sure if CAN_FD is present in mentioned combo but I thought there are specialized IC's for CAN_FD?
It's most unlikely that we could compete with the cost of a Raspberry Pi + existing Duet. We don't have the advantages of scale that Raspberry Pi does.
Not sure how RPi can compete with pricing here since you would not have additional RPi cost but only the cost of Duet? Duet would likely have to be a bit more expensive due to using more expensive processor, though the currently one is definitely not cheap.
We would have to maintain our own Linux build.
I still have old Duet 2 without SBC so my understanding might be a bit off here but aren't you already maintaining your own linux build? Additionally base yocto and/or buildroot images are often provided by manufacturers.
We would have to provide technical support for all the functions that the SBC provides.
That's a tough one although considering how much issues you had with SBC communication maybe it would not be so bad. Just a thought.
Some users prefer to use a different SBC, such as Jetson Nano.
Definitely a downside although linux to linux communication is not so hard so people could easily add more computers if they wish to do so.
We would need to manufacture separate Duets for those who don't want the SBC functionality.
Maybe its misunderstanding here but I would not think that separate duet boards are necessary because duet would in that case effectively be SBC and maybe a stripped down version of linux could be made for those who absolutely would not want any applications.
@stcabrera, you say you connected the extruder to driver 5 .... did you also reconfigure config.g to allow the Duet to talk to driver 5 instead of driver 0?
If you did not reconfigure then the Duet is still talking to driver 0 and the test of plugging into driver 5 does not tell you anything.
Connect the extruder to one of the drives currently configured and see if the problem then shows up on the new driver.
CAUTION: I do not know what will happen if you have a shorted cable and you plug it into another driver channel ... it may just report the error but there is a possibility that the second driver gets killed! I take no responsibility for this advise!
You could also plug one of the currently working drives into driver 0. Probably less risky.
Note that anything that homes will probably break for this test so be ready on the emergency switch or the power button.
@tenaja I've not seen those before, they look like a very interesting concept.
I think for this usage they will take up too much space and cost too much, but I do wonder if the concept could be used - Maybe add-on boards that can adapt banks of outputs to meet various requirements. For example you might want relay outputs, or open collector outputs, 5V outputs, 24V outputs.
I'm trying to balance this with the space usage because I think for the people who are likely to use it (For "desktop" to medium CNC machines essentially), they are likely to have limited space in their control enclosures. For myself, I need to fit everything in a steel enclosure which will slide out beneath an Ikea Lack table which gives me about 500x400x200mm - VFD and all. I think I can get the size down to about 100x50mm or less.
I've also been considering the selection of some of the connectors. I've chosen a right angled RJ45 & RJ11 connector with the release tab on the top, a "flip up" SD card holder which could be mounted away from the edge of the board and a "vertical" micro USB connector which again can be mounted away from the edge of the board. I might even do away with the reset button / external reset input as I don't think it's really required for this application. On the flip side, I'm going to add a lot of status LEDs for every input and output for example.
I typically use EasyEDA as I really like their library integration and I'd probably use JLCPCB's assembly service, but sadly some of the components (The processor for example) do not seem to have footprints right now. I've tried all of the PCB / Schematic software packages and I'm yet to find one I'm really happy with.
Just for others, I see warning (see below) when I open the project but the schematic is fine now.
Warning maeeage (ignore it) :
This schematic was made using older symbol libraries which may break the schematic. Some symbols may need to be linked to a different symbol name. Some symbols may need to be “rescued” (copied and renamed) into a new library. The following changes are recommended to update the project.
Thank you t3p3tony, good job!
PS: The kicad version I use is current version for Ubuntu 20.10 .
One thing to add
I've been hunting around for a small cheap CAN-FD breakout board that can be used with an existing microcontroller (since most of my existing controller boards don't have CAN-FD built in, since it's a bit new)