Duet 2 Ethernet and SBC

A Former User

@smoki3 seems I've missplaced or run out of pogo pins, and with logistis being what it is I doubt I'll test it any time soon.

maybe you could try soldering a regular radial through hole capacitor to the pads and see if it helps? (or see if Tony has anything to add)

smoki3

@bearer I don't have capacitor by hand

wilriker

@smoki3 First of all I can confirm that with external PSU I see the same behavior. I need to check the cause of that next.

A Former User

@wilriker said in Duet 2 Ethernet and SBC:

with external PSU

as in external 5v?

wilriker

@bearer As in external 24V going to VIN of the board.

wilriker

So what I can see is that it does not have anything to do with the internal 5V regulator. If I connect the Duet via USB to the RPi and remove the jumper for internal 5V, i.e. I_5V_EN (completely or put it on E_5V_EN - does not matter) the same problem occurs. So VIN is somehow messing with SPI as soon as it get's to fast transfers as it seems. Still checking.

A Former User

Hm, will try to repeat test with 24v and get the scope out, was under the impression I had used Vin but could be organic bitrot..

smoki3

@wilriker I also tried to disable the internal 5V converter by removing the the jumper. But I also does not help

smoki3

Is the ethernet module also working over SPI?

wilriker

@smoki3 said in Duet 2 Ethernet and SBC:

Is the ethernet module also working over SPI?

Yes, it does.

smoki3

@wilriker Then its even more wired that it is working with the ethernet module and not with a raspberry

A Former User

@smoki3 said in Duet 2 Ethernet and SBC:

Then its even more wired that it is working with the ethernet module and not with a raspberry

Maybe try if the wireless wifi is better? Jokes asides, I find not all boards are the same; will try to log some data and take a look at the signals.

edit: maybe one of the regulators need a minimum load that you loose when removing the ethernet - just something that hit me on the way out

wilriker

@bearer said in Duet 2 Ethernet and SBC:

edit: maybe one of the regulators need a minimum load that you loose when removing the ethernet - just something that hit me on the way out

But it also happens if the internal regulators are not even used (by removing the I_5V_EN jumper) but 5V is provided from external. As soon as 24V is put to VIN it will fail with any kind of largish transfer. Regular (small) status updates work.

A Former User

@wilriker said in Duet 2 Ethernet and SBC:

But it also happens if the internal regulators are not even used

still use the 3.3v one i suspect, which is where the load from the Ethernet module would be; but it shouldn't be affected by Vin.

i've just been to collect my 8 channel thingy and hope to take a look later if I get some helping hands

update: Pi died (likely unrelated to SBC testing, as it died over night with no SBC connected) but further testing on hold pending a new Pi.

smoki3

Anyone found a solution?

Could it be a software issue?

wilriker

@smoki3 Unfortunately not yet. @bearer wanted to put a scope on it and I am still waiting for my scope to finally arrive so I can also have a look at what happens there, too.

I think software is unlikely.

A Former User

Yes, I was supposed to do some digging, did some ~~bike riding~~ flying instead and in summary i now fully appreciate why planes have landing gears ..

Hope to be up and at'en in a few days unless I somehow manage to have another adventure with Mr Murphy

wilriker

I also got my scope meanwhile but it will most likely be only Monday until I can dig deeper into this problem.

JoergS5

I thought about whether it is possible to connect USB of Raspberry and Duet 2, to avoid changing Ethernet/Wifi hardware. The speed of USB 2 of 480 MBit/s should be sufficient.

A Former User

@JoergS5 said in Duet 2 Ethernet and SBC:

The speed of USB 2 of 480 MBit/s should be sufficient.

but the latency and jitter is not deterministic so that might be an issue, and iirc the duet2 chip only does 11 12mbps usb