Duet3D Logo Duet3D
    • Tags
    • Documentation
    • Order
    • Register
    • Login

    Restart DuetControlServer (SBC)

    Scheduled Pinned Locked Moved Unsolved
    General Discussion
    5
    34
    2.2k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • BeosDocundefined
      BeosDoc
      last edited by

      Reseated the ribbon cable...no difference.

      No, it's never connected (duet status: Off) when the pi has been running before the Duet has power. Just to be clear: when duet is powered and I reboot the Pi or restart the duetcontrolservice it will connect.

      Duet 3 firmware is 3.2.2 (read via usb)

      Redid the DuetPi image to SD card (image verified). Had the duet off and booted the pi to go through the first time initialization. Turned the duet on and it connected. Turned the duet off and waited a little bit and turned it back on and it didn't connect. Turned off duet and rebooted Pi, turned on the duet and it connected.

      It looks like it will do it the first time the pi is rebooted but not after that. Also did the apt upgrades after the above, also no change.

      Phaedruxundefined 1 Reply Last reply Reply Quote 0
      • BeosDocundefined
        BeosDoc
        last edited by

        Is it possible that after the first time it waits to connect and then the duet is off that it doesn't check/wait again?

        1 Reply Last reply Reply Quote 0
        • chrishammundefined
          chrishamm administrators
          last edited by

          DSF does indeed wait for the Duet 3 to up and ready. In your case it looks like the might be dodgy connection between the Duet and the Pi which could cause the warnings from your log (all 0x00 or 0xFF could mean a timing issue on the TfrRdy pin).

          Can you post the output of M122 when connected over USB to the Duet (with the Pi attached)?

          Duet software engineer

          1 Reply Last reply Reply Quote 0
          • BeosDocundefined
            BeosDoc
            last edited by

            With Pi attached and running and Duet off.
            Plugged in the USB cable to the Duet, waited a few minutes

            SENT: M122
            READ: === Diagnostics ===
            READ: RepRapFirmware for Duet 3 MB6HC version 3.2.2 running on Duet 3 MB6HC v1.01 or later (SBC mode)
            READ: Board ID: 08DJM-956L2-G43S8-6J9D6-3S46L-KU2YD
            READ: Used output buffers: 1 of 40 (1 max)
            READ: === RTOS ===
            READ: Static ram: 149788
            READ: Dynamic ram: 60988 of which 0 recycled
            READ: Never used RAM 148056, free system stack 190 words
            READ: Tasks: Linux(ready,423) HEAT(blocked,368) CanReceiv(blocked,927) CanSender(blocked,371) CanClock(blocked,360) TMC(blocked,65) MAIN(running,1281) IDLE(ready,19)
            READ: Owned mutexes: USB(MAIN)
            READ: === Platform ===
            READ: Last reset 00:00:33 ago, cause: power up
            READ: Last software reset details not available
            READ: Error status: 0x00
            READ: Aux0 errors 0,0,0
            READ: Aux1 errors 0,0,0
            READ: MCU temperature: min 35.8, current 43.4, max 43.4
            READ: Supply voltage: min 0.2, current 0.2, max 0.3, under voltage events: 0, over voltage events: 0, power good: no
            READ: 12V rail voltage: min 0.1, current 0.2, max 0.2, under voltage events: 0
            READ: Driver 0: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Driver 1: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Driver 2: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Driver 3: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Driver 4: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Driver 5: position 0, ok, reads 0, writes 0 timeouts 0, SG min/max 0/0
            READ: Date/time: 1970-01-01 00:00:00
            READ: Slowest loop: 0.10ms; fastest: 0.00ms
            READ: === Storage ===
            READ: Free file entries: 10
            READ: SD card 0 not detected, interface speed: 37.5MBytes/sec
            READ: SD card longest read time 0.0ms, write time 0.0ms, max retries 0
            READ: === Move ===
            READ: DMs created 125, maxWait 0ms, bed compensation in use: none, comp offset 0.000
            READ: === MainDDARing ===
            READ: Scheduled moves 0, completed moves 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
            READ: === AuxDDARing ===
            READ: Scheduled moves 0, completed moves 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
            READ: === Heat ===
            READ: Bed heaters = -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamberHeaters = -1 -1 -1 -1
            READ: === GCodes ===
            READ: Segments left: 0
            READ: Movement lock held by null
            READ: HTTP is idle in state(s) 0
            READ: Telnet is idle in state(s) 0
            READ: File is idle in state(s) 0
            READ: USB is ready with "M122" in state(s) 0
            READ: Aux is idle in state(s) 0
            READ: Trigger is idle in state(s) 0
            READ: Queue is idle in state(s) 0
            READ: LCD is idle in state(s) 0
            READ: SBC is idle in state(s) 0
            READ: Daemon is idle in state(s) 0
            READ: Aux2 is idle in state(s) 0
            READ: Autopause is idle in state(s) 0
            READ: Code queue is empty.
            READ: === CAN ===
            READ: Messages queued 0, send timeouts 165, received 0, lost 0, longest wait 0ms for reply type 0, free buffers 48
            READ: === SBC interface ===
            READ: State: 0, failed transfers: 0
            READ: Last transfer: 33171ms ago
            READ: RX/TX seq numbers: 0/1
            READ: SPI underruns 0, overruns 0
            READ: Number of disconnects: 0, IAP RAM available 0x2c8a8
            READ: Buffer RX/TX: 0/0-0
            READ: ok
            
            1 Reply Last reply Reply Quote 0
            • BeosDocundefined
              BeosDoc
              last edited by

              Oh, and the above message was with pi dwc saying the Duet status is Off.

              And just incase you want to see what it says when the status is Idle:

              SENT: m122
              READ: === Diagnostics ===
              READ: RepRapFirmware for Duet 3 MB6HC version 3.2.2 running on Duet 3 MB6HC v1.01 or later (SBC mode)
              READ: Board ID: 08DJM-956L2-G43S8-6J9D6-3S46L-KU2YD
              READ: Used output buffers: 2 of 40 (17 max)
              READ: === RTOS ===
              READ: Static ram: 149788
              READ: Dynamic ram: 63684 of which 76 recycled
              READ: Never used RAM 145284, free system stack 146 words
              READ: Tasks: Linux(ready,81) HEAT(blocked,297) CanReceiv(blocked,834) CanSender(blocked,352) CanClock(blocked,352) TMC(blocked,19) MAIN(running,1147) IDLE(ready,19)
              READ: Owned mutexes: USB(MAIN)
              READ: === Platform ===
              READ: Last reset 00:03:50 ago, cause: power up
              READ: Last software reset details not available
              READ: Error status: 0x00
              READ: Aux0 errors 0,0,0
              READ: Aux1 errors 0,0,0
              READ: MCU temperature: min 40.3, current 40.5, max 40.7
              READ: Supply voltage: min 31.2, current 31.3, max 31.3, under voltage events: 0, over voltage events: 0, power good: yes
              READ: 12V rail voltage: min 11.9, current 12.0, max 12.0, under voltage events: 0
              READ: Driver 0: position 800, standstill, reads 45086, writes 3 timeouts 0, SG min/max 0/298
              READ: Driver 1: position 800, standstill, reads 45087, writes 3 timeouts 0, SG min/max 0/263
              READ: Driver 2: position 0, standstill, reads 45087, writes 3 timeouts 0, SG min/max 0/160
              READ: Driver 3: position 0, standstill, reads 45086, writes 3 timeouts 0, SG min/max 0/169
              READ: Driver 4: position 0, standstill, reads 45086, writes 3 timeouts 0, SG min/max 0/207
              READ: Driver 5: position 0, standstill, reads 45086, writes 3 timeouts 0, SG min/max 0/208
              READ: Date/time: 2021-03-01 09:45:31
              READ: Slowest loop: 88.98ms; fastest: 0.04ms
              READ: === Storage ===
              READ: Free file entries: 10
              READ: SD card 0 not detected, interface speed: 37.5MBytes/sec
              READ: SD card longest read time 0.0ms, write time 0.0ms, max retries 0
              READ: === Move ===
              READ: DMs created 125, maxWait 206056ms, bed compensation in use: none, comp offset 0.000
              READ: === MainDDARing ===
              READ: Scheduled moves 10, completed moves 10, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
              READ: === AuxDDARing ===
              READ: Scheduled moves 0, completed moves 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
              READ: === Heat ===
              READ: Bed heaters = 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamberHeaters = -1 -1 -1 -1
              READ: === GCodes ===
              READ: Segments left: 0
              READ: Movement lock held by null
              READ: HTTP* is idle in state(s) 0
              READ: Telnet is idle in state(s) 0
              READ: File is idle in state(s) 0
              READ: USB is ready with "m122" in state(s) 0
              READ: Aux is idle in state(s) 0
              READ: Trigger* is idle in state(s) 0
              READ: Queue is idle in state(s) 0
              READ: LCD is idle in state(s) 0
              READ: SBC is idle in state(s) 0
              READ: Daemon is idle in state(s) 0
              READ: Aux2 is idle in state(s) 0
              READ: Autopause is idle in state(s) 0
              READ: Code queue is empty.
              READ: === Filament sensors ===
              READ: Extruder 0 sensor: no filament
              READ: Extruder 1 sensor: no filament
              READ: === CAN ===
              READ: Messages queued 360, send timeouts 0, received 2232, lost 0, longest wait 0ms for reply type 0, free buffers 48
              READ: === SBC interface ===
              READ: State: 4, failed transfers: 0
              READ: Last transfer: 0ms ago
              READ: RX/TX seq numbers: 7559/7559
              READ: SPI underruns 0, overruns 0
              READ: Number of disconnects: 0, IAP RAM available 0x2c8a8
              READ: Buffer RX/TX: 0/0-0
              READ: ok
              
              1 Reply Last reply Reply Quote 0
              • gloomyandyundefined
                gloomyandy
                last edited by

                @BeosDoc Can you take a look at the syslog file (/var/log/syslog) and see if you have any lines that look similar to:

                 systemd[1]: duetcontrolserver.service: Start request repeated too quickly.
                
                BeosDocundefined 1 Reply Last reply Reply Quote 0
                • BeosDocundefined
                  BeosDoc @gloomyandy
                  last edited by

                  @gloomyandy

                  Yes there is, only 1 occurrence. I have seen it before the other day as well.

                  Mar  1 09:39:52 duet3 DuetControlServer[30541]: [info] Settings loaded
                  Mar  1 09:39:52 duet3 DuetControlServer[30541]: [info] Environment initialized
                  Mar  1 09:39:53 duet3 DuetControlServer[30541]: [fatal] Could not connect to Duet (Timeout while waiting for transfer ready pin)
                  Mar  1 09:39:53 duet3 systemd[1]: duetcontrolserver.service: Failed with result 'protocol'.
                  Mar  1 09:39:53 duet3 systemd[1]: Failed to start Duet Control Server.
                  Mar  1 09:39:53 duet3 systemd[1]: duetcontrolserver.service: Service RestartSec=100ms expired, scheduling restart.
                  Mar  1 09:39:53 duet3 systemd[1]: duetcontrolserver.service: Scheduled restart job, restart counter is at 5.
                  Mar  1 09:39:53 duet3 systemd[1]: Stopped Duet Control Server.
                  Mar  1 09:39:53 duet3 systemd[1]: duetcontrolserver.service: Start request repeated too quickly.
                  Mar  1 09:39:53 duet3 systemd[1]: duetcontrolserver.service: Failed with result 'protocol'.
                  Mar  1 09:39:53 duet3 systemd[1]: Failed to start Duet Control Server.
                  Mar  1 09:39:53 duet3 DuetWebServer[589]: #033[40m#033[1m#033[33mwarn#033[39m#033[22m#033[49m: DuetWebServer.Services.ModelObserver[0]
                  Mar  1 09:39:53 duet3 DuetWebServer[589]:       Failed to synchronize machine model
                  Mar  1 09:39:53 duet3 DuetWebServer[589]: System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (111): Connection refused /var/run/dsf/dcs.sock
                  Mar  1 09:39:53 duet3 DuetWebServer[589]:    at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
                  Mar  1 09:39:53 duet3 DuetWebServer[589]:    at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
                  Mar  1 09:39:53 duet3 DuetWebServer[589]:    at DuetAPIClient.BaseConnection.Connect(ClientInitMessage initMessage, String socketPath, CancellationToken cancel$
                  Mar  1 09:39:53 duet3 DuetWebServer[589]:    at DuetWebServer.Services.ModelObserver.Execute() in /home/christian/Duet3D/DuetSoftwareFramework/src/DuetWebServe$
                  
                  

                  And when I do a systemctl status duetcontrolserver, duet on and pi duet status of Off, I get:

                  Mar 01 09:53:30 duet3 DuetControlServer[31177]: [warn] Note: RepRapFirmware didn't receive valid data either (code 0xffffffff)
                  Mar 01 09:53:30 duet3 DuetControlServer[31177]: [warn] Restarting transfer because the number of maximum retries has been exceeded
                  Mar 01 09:53:30 duet3 DuetControlServer[31177]: [warn] Bad header CRC16 (expected 0x0000, got 0x0272)
                  Mar 01 09:53:30 duet3 DuetControlServer[31177]: [warn] Note: RepRapFirmware didn't receive valid data either (code 0xffffffff)
                  Mar 01 09:53:31 duet3 DuetControlServer[31177]: [warn] Bad header CRC16 (expected 0x0000, got 0x0272)
                  Mar 01 09:53:31 duet3 DuetControlServer[31177]: [warn] Note: RepRapFirmware didn't receive valid data either (code 0xffffffff)
                  Mar 01 09:53:31 duet3 DuetControlServer[31177]: [warn] Bad header CRC16 (expected 0x0000, got 0x136c)
                  Mar 01 09:53:31 duet3 DuetControlServer[31177]: [warn] Note: RepRapFirmware didn't receive valid data either (code 0xffffffff)
                  Mar 01 09:53:31 duet3 DuetControlServer[31177]: [warn] Restarting transfer because the number of maximum retries has been exceeded
                  Mar 01 10:00:55 duet3 DuetControlServer[31177]: [warn] RepRapFirmware got a bad header checksum
                  
                  
                  1 Reply Last reply Reply Quote 0
                  • gloomyandyundefined
                    gloomyandy
                    last edited by

                    If you get that message it basically means that systemd will no longer restart the duetcontrolserver service.

                    The systemd documentation is a little tricky to follow but this message is generated if the service needs to be restarted more than a certain number of times over a period of time. In this case I think the defaults are 5 times in 10 seconds. I think this can happen if the Duet is turned off and the transfer ready pin floats high.

                    Given that the main purpose of the SBC is to talk to the Duet I'm not sure it really makes sense to disable the service in this way. If you are happy making changes to the rPi config files (worse case you just reinstall everything), you can tell systemd not to disable a service in this situation by adding the following line:

                    StartLimitIntervalSec=0
                    

                    to the [unit] part of the service control file. In this case that file is:

                    /etc/systemd/system/multi-user.target.wants/duetcontrolserver.service
                    

                    if you modify to look like this:

                    [Unit]
                    Description=Duet Control Server
                    StartLimitIntervalSec=0
                    
                    [Service]
                    ExecStart=/opt/dsf/bin/DuetControlServer
                    TimeoutStopSec=60
                    Restart=always
                    Type=notify
                    User=dsf
                    Group=dsf
                    UMask=0002
                    CapabilityBoundingSet=CAP_SYS_PTRACE CAP_DAC_READ_SEARCH CAP_SYS_TIME
                    AmbientCapabilities=CAP_SYS_PTRACE CAP_DAC_READ_SEARCH CAP_SYS_TIME
                    
                    [Install]
                    WantedBy=sysinit.target
                    

                    Then the action that disables the service should be turned off. Note that after making the change you should run the following commands:

                    pi@duet3:~ $ sudo systemctl daemon-reload
                    pi@duet3:~ $ sudo systemctl restart duetcontrolserver
                    

                    May be a good idea to make a copy of the file before you edit it.

                    I've seen the service be disabled when updating firmware on the STM32/LPC port of RRF (that I look after). In that case flashing new firmware is different to the Duet and the firmware restart takes longer which can sometimes trigger systemd to disable the control server. Making the above change seems to fix that problem for me. It would be interesting to see if it helps with your problem.

                    BeosDocundefined 2 Replies Last reply Reply Quote 1
                    • Phaedruxundefined
                      Phaedrux Moderator @BeosDoc
                      last edited by

                      @BeosDoc said in Restart DuetControlServer (SBC):

                      Reseated the ribbon cable...no difference.

                      Do you have another ribbon cable to test with or possibly make some jumper cables?

                      @gloomyandy said in Restart DuetControlServer (SBC):

                      StartLimitIntervalSec=0

                      I've asked christian to take a look at this. Regardless, the Duet and Pi should be making a connection so the retry shouldn't come into play. Seems like either a bad cable or damaged pins.

                      Z-Bot CoreXY Build | Thingiverse Profile

                      BeosDocundefined 2 Replies Last reply Reply Quote 0
                      • BeosDocundefined
                        BeosDoc @gloomyandy
                        last edited by

                        @gloomyandy

                        I don't have that file in /etc/systemd/system/multi-user.target.wants

                        I did find it in /etc/systemd/system/sysinit.target.wants/

                        Mine at that location is currently:

                        [Unit]
                        Description=Duet Control Server
                        
                        [Service]
                        ExecStart=/opt/dsf/bin/DuetControlServer
                        TimeoutStopSec=15
                        Restart=always
                        Type=notify
                        User=dsf
                        Group=dsf
                        UMask=0002
                        CapabilityBoundingSet=CAP_SYS_PTRACE CAP_DAC_READ_SEARCH CAP_SYS_TIME
                        AmbientCapabilities=CAP_SYS_PTRACE CAP_DAC_READ_SEARCH CAP_SYS_TIME
                        
                        [Install]
                        WantedBy=sysinit.target
                        
                        1 Reply Last reply Reply Quote 0
                        • BeosDocundefined
                          BeosDoc @Phaedrux
                          last edited by

                          @Phaedrux said in Restart DuetControlServer (SBC):

                          @BeosDoc said in Restart DuetControlServer (SBC):

                          Reseated the ribbon cable...no difference.

                          Do you have another ribbon cable to test with or possibly make some jumper cables?

                          No other ribbon cable, just the one supplied with your board and I have reseated it. I have short jumper wires I can use. I want to verify the required pins: 19,21,22,23,34 and 20 for ground. Is pin 17 (3.3V) and/or Pin 2/4 (5v) required? SBC has it's own power supply and the duet no jumpers on 5V -> SBC and also SBC ->5V

                          1 Reply Last reply Reply Quote 0
                          • gloomyandyundefined
                            gloomyandy
                            last edited by

                            @Phaedrux My understanding is that problem occurs when the rPi is started but the Duet board does not have any power. In that situation it is possible that the duetcontrolserver service has been suspended (due to the too many restarts), before the Duet board is even started. If that happens there is no way that the Duet is ever going to connect, because it has nothing to connect to. Certainly if that "duetcontrolserver.service: Start request repeated too quickly" message is in the syslog it would indicate that the service is being suspended. Either way the change is easy to make and then test to see if it helps with the problem.

                            @BeosDoc That's odd, perhaps it has been moved at some point, my rPi image was created probably a year or so ago (but has been updated continuously since then).

                            1 Reply Last reply Reply Quote 1
                            • Phaedruxundefined
                              Phaedrux Moderator
                              last edited by

                              To be honest I'm not sure about the 3.3 and 5v pins. Try without if you're short on jumper wires.

                              Z-Bot CoreXY Build | Thingiverse Profile

                              1 Reply Last reply Reply Quote 0
                              • BeosDocundefined
                                BeosDoc
                                last edited by

                                I'll try the jumpers first. Then I'll try the changes to that file.

                                1 Reply Last reply Reply Quote 0
                                • BeosDocundefined
                                  BeosDoc
                                  last edited by

                                  First part. I replaced the ribbon cable with very short, 9cm (ribbon is 20cm), and brand new jumpers. Initial boot worked. After that it still had the status of Off.

                                  FYI: You do need pin 17 (3.3V) hooked up. Without it, it didn't see it at all.

                                  For future reference Duet 3 > rPi you need pins 17, 19, 21, 22, 23, 24, 26 (not sure about 26) and one of the grounds (like 20 and/or 25

                                  Now for the second part with the file

                                  dc42undefined 1 Reply Last reply Reply Quote 1
                                  • BeosDocundefined
                                    BeosDoc @gloomyandy
                                    last edited by

                                    @gloomyandy said in Restart DuetControlServer (SBC):

                                    Given that the main purpose of the SBC is to talk to the Duet I'm not sure it really makes sense to disable the service in this way. If you are happy making changes to the rPi config files (worse case you just reinstall everything), you can tell systemd not to disable a service in this situation by adding the following line:
                                    StartLimitIntervalSec=0

                                    to the [unit] part of the service control file. In this case that file is:
                                    /etc/systemd/system/multi-user.target.wants/duetcontrolserver.service

                                    I modified the file /etc/systemd/system/sysinit.target.wants/duetcontrolserver.service

                                    I tried it several times and it didn't see it 😞

                                    1 Reply Last reply Reply Quote 0
                                    • BeosDocundefined
                                      BeosDoc @Phaedrux
                                      last edited by

                                      @Phaedrux said in Restart DuetControlServer (SBC):

                                      I've asked christian to take a look at this. Regardless, the Duet and Pi should be making a connection so the retry shouldn't come into play. Seems like either a bad cable or damaged pins.

                                      If it was a bad cable or damaged pins, then it probably wouldn't work at all or there would be lots of comm errors. If I reboot the pi or restart DuetControlServer it works find, I've done several prints.

                                      1 Reply Last reply Reply Quote 0
                                      • gloomyandyundefined
                                        gloomyandy
                                        last edited by

                                        @BeosDoc Are you getting any

                                        systemd[1]: duetcontrolserver.service: Start request repeated too quickly.
                                        

                                        messages now in your syslog file? Are you rebooting the rPi to test this?

                                        BeosDocundefined 1 Reply Last reply Reply Quote 0
                                        • chrishammundefined
                                          chrishamm administrators
                                          last edited by

                                          @gloomyandy Thanks for pointing out this limitation, I'll check if I can integrate your change in the next software version. The automatic fail detection wasn't an issue in earlier DSF versions because that always had a restart delay of 5 seconds.

                                          @BeosDoc What I find odd about your report is that you do get occasional transfers (albeit with bad checksums) so I'm wondering if there is something wrong with the SPI peripheral either on the Pi or the Duet. Can you run the spidev_test procedure as described here? I'll update the docs with better troubleshooting instructions soon.

                                          Duet software engineer

                                          BeosDocundefined 1 Reply Last reply Reply Quote 0
                                          • dc42undefined
                                            dc42 administrators @BeosDoc
                                            last edited by dc42

                                            @BeosDoc said in Restart DuetControlServer (SBC):

                                            First part. I replaced the ribbon cable with very short, 9cm (ribbon is 20cm), and brand new jumpers. Initial boot worked. After that it still had the status of Off.

                                            FYI: You do need pin 17 (3.3V) hooked up. Without it, it didn't see it at all.

                                            For future reference Duet 3 > rPi you need pins 17, 19, 21, 22, 23, 24, 26 (not sure about 26) and one of the grounds (like 20 and/or 25

                                            To clarify: using Duet 3 MB6HC version 1.01 and later, or a Duet 3 Mini, you do need the 3.3v pin because it feeds the voltage translation buffer. You do not need the 5V pin.

                                            It's better to connect more than one ground, especially the ground pins close to the SPI pins.

                                            Duet WiFi hardware designer and firmware engineer
                                            Please do not ask me for Duet support via PM or email, use the forum
                                            http://www.escher3d.com, https://miscsolutions.wordpress.com

                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Unless otherwise noted, all forum content is licensed under CC-BY-SA