Duet 2 Pro 4 U

Edgars Batna

The processor will have about the same power as Duet 2 but more flash memory and RAM to make room for firmware improvements.

Is there a significant reason to not upgrade the CPU further? It's better to have the power and not need it. Also, you know this better than I do, but more features / bigger code usually means longer critical path.

I've also seen Atmel offering dual core SAMs. That would be quite fun having some tasks not blocking each other so much.

Just brainstorm/-farting here.

dc42

@Edgars-Batna said in Duet 2 Pro 4 U:

Is there a significant reason to not upgrade the CPU further? It's better to have the power and not need it. Also, you know this better than I do, but more features / bigger code usually means longer critical path.

It's a matter of getting the price vs performance right. The faster processors from Microchip are a lot more expensive; whereas we are aiming to price this board at significantly less than the Duet WiFi and Duet Ethernet (although if the £ plummets in December then that may not be possible). For this board it would have been possible to switch to a non-Microchip processor because it doesn't need to support CAN-FD, but that would have increased the software development cost and time substantially.

The additional features we have added to RRF recently do not put a significant additional load on the CPU. They are mostly alternative options (e.g. different kinematics, and 12864 LCD support as an alternative to PanelDue support) or features that are used only occasionally (e.g. conditional GCode, and probing in directions other than Z). So we don't need increased processor power yet.

bot

@dc42 Would faster CPU clock speeds and/or increased memory allow for faster printing of GCode with many small segments?

I think Edgars is interested in having very fine mesh/segment/toolpath resolution while printing at increased speeds. I'm interested in this too, but I'm happy enough with the current Duet that I wouldn't be bothered if it never comes. Just a casual wish of mine to experiment and push the envelope.

That said, I know you have ideas about motion planning, electronics, etc. that are far beyond my understanding. So, I'm just trying to convey the reason why we think we want faster CPUs. Perhaps you have a better way of achieving it which is even potentially currently possible on Duet hardware.

pixelpieper

@dc42 why go the extension board route for the extra steppers? I would prefer to have them all on the board, gives a better thermal performance and you do not have to stock an extra board. I assume you look into 2209s, the additional cost for three more is not that high. You still could have a lite version of the same board where you only populate 5...

lepetitnicolas

@dc42
Hello,
When do you release this new card ?
Currently, i used raspberry with klipper and the support for raspberry like duet3 is a good thing
Thanks

@lepetitnicolas said in Duet 2 Pro 4 U:

When do you release this new card ?

this is the latest news https://forum.duet3d.com/topic/17409/duet-3-mini-5-initial-announcement/1?_=1593996217004

not sure if that was the board in question?

dc42

@pixelpieper said in Duet 2 Pro 4 U:

@dc42 why go the extension board route for the extra steppers? I would prefer to have them all on the board, gives a better thermal performance and you do not have to stock an extra board. I assume you look into 2209s, the additional cost for three more is not that high. You still could have a lite version of the same board where you only populate 5...

A board with 8 drivers populated would need to be significantly larger. It would no longer be possible to keep it the same form factor as the existing Duet WiFi/Ethernet/Maestro, and the large PCB would add to the cost. Also, having an 8-driver board and offering a lite version with only 5 drivers populated is not a good option either for us (because we would have to get the production balance right and hold stocks of both types) or our users (because the 5-driver version would not be easily upgradable).

dc42

Here are the prototypes, both WiFi and Ethernet versions.

2020-07-05 18.02.31.jpg

@dc42 said in Duet 2 Pro 4 U:

both WiFi and Ethernet

two different pcb's or just for the prototypes?

dc42

Two different PCBs.

jay_s_uk

@dc42
Is that a ESP-WROOM-02U wifi module?

@jay_s_uk said in Duet 2 Pro 4 U:

ESP-WROOM-02U

it was more legible on another photo, but yes.

pixelpieper

Neat! I really like where this is going... Do I spot a CAN-FD-Connector in the left top?

dc42

@pixelpieper said in Duet 2 Pro 4 U:

Neat! I really like where this is going... Do I spot a CAN-FD-Connector in the left top?

No, that's the SWD connector.

bot

~~Did I miss where the types of drivers were announced? 5160? 2209?~~

Never mind, saw the other thread.

What would be the differentiation between this and the Duet2 Eth/Wifi?

pixelpieper

@bot Modern drivers with Stealthchop, more Memory, Raspberry-Pi interface, Neopixel-Support

bot

Hmmm, more memory sounds good. How much more?

I don't really care about the sound of the drivers. The 2260s in the Duet 2 work fine for me. Do the 2209's provide a slight reduction in the max amperage the drivers can push?

dc42

@bot said in Duet 2 Pro 4 U:

I don't really care about the sound of the drivers. The 2260s in the Duet 2 work fine for me. Do the 2209's provide a slight reduction in the max amperage the drivers can push?

Yes, they will probably be limited to about 2.0A peak. For users needing higher motor current, we have Duet 3.

pixelpieper

@bot AFAIK double the flash, don' know about SRAM. The 2209s are rated up to 2A, so yes a downgrade from the Duet2 but an update from the Maestro.

dc42

@pixelpieper said in Duet 2 Pro 4 U:

@bot AFAIK double the flash, don' know about SRAM.

Double both flash and SRAM.