Sammy-C21 CAN errors

dc42

Is the green LED on the Sammy blinking in sync with the red LED on the Duet 3 main board?

R3D

No it is not, it is flashing faster.

Thanks,

dc42

In that case, it has failed to establish CAN sync. Check that you have the CAN-H and CAN-L wires the right way round. It's safe to swap them over if you are not sure.

R3D

@dc42 tried every combination. pinned each of the four wires to a separate pin and went through every combination of wires to the sammy. had it wired exactly as you showed in your wiki and had the included jumper on bypass 0_L as shown as well as jumping 0_H, and leaving both off, all with no luck.

Thanks,

dc42

Can you post a photo of how you have wired it?

Which firmware versions are you running on the main board and on the Sammy?

R3D

@dc42 Not sure which version the sammy is running, just used the standard SammyC21-Debug build configuration of the duet 3 expansion project that was linked in the using the Sammy-C21 wiki. the duet 3 is running 3.1.1. Hopefully the pictures aren't too difficult to see how it is wired.

Thanks,

https://docs.google.com/document/d/1Bp4xujc3g4FNgR2rNiLPNwxMCp3kJDNa_W3WrCJcFXg/edit?usp=sharing

R3D

@dc42 Is there somewhere in the source code files that would show the firmware version? or a way to connect to the sammy with the ICE and get it that way? Maybe with a terminal emulator?

Thanks,

A Former User

@R3D you could run strings on the binary f.ex.?

bearer@rama:~/eclipse/firmware/Duet3Expansion$ strings SAMMYC21/Duet3Firmware_SAMMYC21.bin | grep 2020
3.1.0+ (2020-07-01b3)

(might not be the best grep, but it'll work all year..)

JoergS5

@R3D I wonder whether you have changed the frequency for the sammy?

https://forum.duet3d.com/topic/16448/can-fd-generic-io/14

R3D

@JoergS5 Does the sammy default to a different frequency on the CAN bus? I'm assuming I can just change this via M952.

Thanks,

JoergS5

@R3D I don't know the consequences of wrong frequency.

R3D

Also your link to the post states that the bootloader has the clock multiplier changed in it already, which I did flash to the sammy with the ICE prior to uploading firmware...

JoergS5

@R3D ok, then it would be ok.

A Former User

@JoergS5 said in Sammy-C21 CAN errors:

https://forum.duet3d.com/topic/16448/can-fd-generic-io/14

i think that is not relevant when building the SAMMYC21 configuration as dc42 has taken care if it all for us.

R3D

I also loaded the firmware binary through the ICE as well, possibly overwriting the bootloader and thus removing the clock multiplier fix?

If I am following this correctly that is.

Thanks,

A Former User

@R3D said in Sammy-C21 CAN errors:

I also loaded the firmware binary through the ICE as well,

use the SAMMYC21-Debug build config in that case
(edit ref: https://duet3d.dozuki.com/Wiki/Using_the_Sammy-C21_development_board_with_Duet_3#Section_Debugging_your_own_firmware)

R3D

I did, in my previous comments I did specify this.

Thanks,

JoergS5

@R3D maybe you can debug sammy and check can communication. The sammy has a SWD connector (but the pins must be soldered).

R3D

So i have the ICE in the SAMMY with both powered on, I have it connected in atmel studio 7 in the device programming tab, but I am having trouble locating any information regarding the CAN bus.

Any suggestions?

Thanks,

dc42

It's been over a month since I tested the SammyC21 firmware build. I've just built and loaded the debug build through ICE and I am getting the same issue - no CAN connection. I'll fix this today if i don't run out of time.