Duet3/pi DCS is unavailable after wiring 24V

fractalengineer

@bearer Ok so the next steps would be:

1-Stopping DCS and rerunning the test
2-Jump RDY (22) to 3.3v
3-Change RDY pin
4-Swap to the other Rpi
5-Wire with all jumpers

Am I correct?

Those are pretty heavy operations I'll try to hang there but I hope I won't mess anything

Here's 1-Stopping DCS and rerunning the test

pi@duet3:~ $ sudo systemctl stop duetwebserver
pi@duet3:~ $ sudo systemctl stop duetcontrolserver
pi@duet3:~ $ RDY=22 CS=24 ; {
gpio -1 mode $RDY in
> gpio -1 mode $CS out
> gpio -1 mode $RDY in
> gpio -1 write $CS 1 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"
> gpio -1 write $CS 0 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"
> { ~/spidev-test/spidev_test -v -s 8000000 -D /dev/spidev0.0 && echo RX should equal TX. ;} | tail -n3 | cut -b-100 ;}
(Pin RDY/22) 0 should equal 1 (Pin CS/24)
(Pin RDY/22) 0 should equal 0 (Pin CS/24)
TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D
RX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D
RX should equal TX.

A Former User

@fractalengineer

Tbh, I'd start by just having jumpers on the other pi.

Then I'd move the jumpers to jump RDY(26) to CS(24) and run the gpio test again, targeting the correct RDY pin. edit: actually run the gpio test before and after changing the jumper, ignoring the output the first time (to ensure the pin is in input mode before connecting it)

If still no dice, then I'd wire RDY to 3.3v and run the gpio test again, targeting the correct RDY pin be it 22 or 26. (again run gpio test before making changes to ensure pin is input)

If all of that fails then no point in the rest.

If something succeeds then try with the duet and whatever combination of Pi and RDY pin gave the desired test result.

Also note I edited the post about editing config.json to reflect which pin number to enter if you get to that point.

fractalengineer

@bearer thanks;

Ok so here's my wiring;

I wired both grounds and both +5v; is this about right?

A Former User

@fractalengineer said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

I wired both grounds and both +5v; is this about right?

Yes, they're just double up to reduce voltage drop.

It looks right as far as I can tell; but not easy to see if blue/purple was swapped on the way over. The rest I'm reasonable confident in.

Although I'd be very surprised to see it working if the gpio test didn't indicate RDY and CS had the same readings on each line.

dc42

Does the soldering of the 26-way connector look OK on the underside of the Duet?

chrishamm

Side note: DCS uses the driver that provides /dev/gpiochip because it allows faster reactions to pin level transitions than the standard sysfs GPIO driver. So I recommend using the tools from the gpiod package for GPIO troubleshooting (install via apt-get install gpiod). So by running gpiodetect you can see all the available GPIO lines. Once you shut down DCS, you can check the pin state by running gpioget 0 25 and that should output 1. I'll install that package by default in the next DuetPi version.

A Former User

@chrishamm said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

So I recommend using the tools from the gpiod package for GPIO troubleshooting

ah, thats why wiringpi wasn't a dependency any more. I'll work it into the instructions at a later time. thanks for the heads up.

So by running gpiodetect you can see all the available GPIO lines.

i think you meant gpioinfo but close enough.

fractalengineer

@bearer damn you caught it!

Thanks; ok so the problem still exists with the jumpers; not sure if relevant wired to duet but here's the test:

pi@duet3:~ $ RDY=22 CS=24 ; {  gpio -1 mode $CS out; gpio -1 mode $RDY in; gpio -1 write $CS 1 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"; gpio -1 write $CS 0 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"; { ~/spidev-test/spidev_test -v -s 8000000 -D /dev/spidev0.0 && echo RX should equal TX. ;} | tail -n3 | cut -b-100 ;}
(Pin RDY/22) 0 should equal 1 (Pin CS/24)
(Pin RDY/22) 0 should equal 0 (Pin CS/24)
TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D
RX | 05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RX should equal TX.

@dc42 solderings look perfect; both on the duet and the pi

A Former User

@fractalengineer said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

not sure if relevant wired to duet but here's the test:

no its not, it'll only give the same readings if the pins are shorted; which is why I would wait with connecting the duet until testing with just jumpers show its working properly.

fractalengineer

@bearer Ok here's the result moving RDY from 22 to 26:

24 is bridged to 26

pi@duet3:~ $ gpio -1 mode 26 in
pi@duet3:~ $ RDY=26 CS=24 ; {
> gpio -1 mode $CS out
> gpio -1 mode $RDY in
> gpio -1 write $CS 1 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"
> gpio -1 write $CS 0 && echo "(Pin RDY/$RDY) `gpio -1 read $RDY` should equal `gpio -1 read $CS` (Pin CS/$CS)"
> { ~/spidev-test/spidev_test -v -s 8000000 -D /dev/spidev0.0 && echo RX should equal TX. ;} | tail -n3 | cut -b-100 ;}
(Pin RDY/26) 1 should equal 1 (Pin CS/24)
(Pin RDY/26) 0 should equal 0 (Pin CS/24)
TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D
RX | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RX should equal TX.

A Former User

Okay, pin 22 dead. progress.

Now back to editing config.json.

The physical pin numbers on the PI does not match the internal numbering in the CPU, config.json needs the internal numbering.

Run this mess of a command and check it outputs 7.
gpio readall | cut -b41-90 | grep "^| 26 " | cut -b35-38

then edit /opt/dsf/conf/config.json and find the line

"TransferReadyPin": 25,
change it to
"TransferReadyPin": 7,

(or whatever number the previous gpio readall... command returned)

buy volcano insurance and try the duet making sure to wire pin 22 from the duet to pin 26 on the pi

edit: suddenly I have a concern about rebooting the pi in this configuration. do not reboot the pi with the modified wiring; I'll need a bit of time to test if its aproblem that the pin reverts to an output at boot. (or maybe its better to just pick anoter pin that defaults to input right of the bat. I picked 26 because it only meant moving the jumper one possition over.

Yeah, after consideration I'd use physical pin 18 instead.
gpio readall | cut -b41-90 | grep "^| 18 " | cut -b35-38
should return (internal pin number) 24, and that number goes into config.json after then wiring physical 18 on the pi to pin 22 on the Duet. Pardon the detour, making the path up as we go - on the bright side you've singel handedly made sure all future troubles have a path to follow and you've done it like a champ!

fractalengineer

Wow @bearer you absolutely killed it

Thank you everyone!

A Former User

@fractalengineer said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

you absolutely killed it

...again with the jokes, but technically you killed it, i fixed it, or put a band aid on it at least ...

volcano insurance ftw!

Danal

WHOO HOOO! As a mostly bystander, congrats to @bearer for all the "figurin" and to @fractalengineer who now has a running machine.

@fractalengineer, now the fun REALLY starts!

fractalengineer

@bearer lol yess

I was thinking for a neater build would it make sense to swap the 22 and 18 wires like so?

A Former User

@fractalengineer said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

@bearer lol yess

I was thinking for a neater build would it make sense to swap the 22 and 18 wires like so?

Its a neat idea, but i'd trim a bit off to avoid reterminating the idc where the insulation is already displaced

dc42

This way (as on the Duet 2 automated test equipment prototype on my desk) avoids having to disturb the IDC connectors:

2020-04-25 21.28.29.jpg

MaxGyver

Hey all,

I have the same "DCS is unavailable" issue with my Duet 3 v1.0 and RPI 4.

Do I understand correctly that swapping wires 22 and 18 on the ribbon cable will fix this issue ?
I have installed the lastest DuetPI version on my RPI and also reflashed my Duet3 with RRF 3 Release 3.01-RC12.

Cheers Max

A Former User

@MaxGyver said in Duet3/pi flashing Diag LED after wiring 24V DCS is unavailable:

Do I understand correctly that swapping wires 22 and 18 on the ribbon cable will fix this issue ?

In general probaly no, pretty spescial case with a damaged raspberry pi, you can test it using the same tools as described in the thread.

More likely RRF and DSF is out of sync, which version of DSF are you using - if you just downloaded the DuetPi image it will be using an old stable version not compatible with RRF 3.01-RC12. Switch to unstable package feed or downgrade RRF to 3.0 release.

Phaedrux

@MaxGyver Best to start a new thread to fully diagnose your issue.