Hello,
for the application described in this other topic I am trying to implement a simple speed controlled extruder using a Duet3.
I tried using a macro, but that didn't work. The refresh rate was not good enough. In a second attempt, by modifying the FW I got a bit further.
Currently I read the ZProbe value in CalcNextStepTimeFull and use it to scale nextStepTime.
This works using a potentiometer on the input, changes are applied immedately to the speed, but the overall duration of the G1 move doesn't seems to take the scaled step time into account, so that after an extrusion I alwas get a dead time where no other drive movements are executed.

I probably didn't grab all details of how the re-calculation is planned. Can someone point me out on what else needs to be done?

bool DriveMovement::CalcNextStepTimeFull(const DDA &dda) noexcept
pre(nextStep <= totalSteps; stepsTillRecalc == 0)
{

	const auto zp2 = reprap.GetPlatform().GetEndstops().GetZProbe(0);

	NewSpeedFactor = uint32_t(zp2->GetReading());
	NewSpeedFactor = max<uint32_t>(NewSpeedFactor,100);
	NewSpeedFactor = min<uint32_t>(NewSpeedFactor,1000);
...
	switch (state)
	{
	case DMState::cartLinear:									// linear steady speed
		nextStepScaled=(uint32_t)((uint64_t)(nextStep * UsedSpeedFactor) >> 10);
...
		nextCalcStepTime = pB + (float)(nextStepScaled + stepsTillRecalc) * pC ;
...
	nextStepTime = NextCalcStepTime - (stepsTillRecalc * stepInterval);
...

Thanks!

Here is the report using M122 while the system is stuck..

8/16/2022, 9:50:35 PM	M122
=== Diagnostics ===
RepRapFirmware for Duet 3 MB6HC version 3.4.2rc1+ (2022-08-14 11:05:55) running on Duet 3 MB6HC v1.01 or later (standalone mode)
Board ID: 08DJM-956BA-NA3TJ-6JKDL-3S86K-9T92T
Used output buffers: 4 of 40 (20 max)
=== RTOS ===
Static ram: 151000
Dynamic ram: 96152 of which 0 recycled
Never used RAM 100520, free system stack 192 words
Tasks: NETWORK(ready,26.8%,209) ETHERNET(notifyWait,0.1%,173) HEAT(notifyWait,0.0%,321) Move(notifyWait,0.0%,265) CanReceiv(notifyWait,0.0%,943) CanSender(notifyWait,0.0%,335) CanClock(delaying,0.0%,334) TMC(notifyWait,7.6%,92) MAIN(running,65.4%,1083) IDLE(ready,0.1%,30), total 100.0%
Owned mutexes:
=== Platform ===
Last reset 00:03:24 ago, cause: reset button
Last software reset at 2022-08-16 21:24, reason: User, GCodes spinning, available RAM 100592, slot 2
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0044a000 BFAR 0x00000000 SP 0x00000000 Task MAIN Freestk 0 n/a
Error status: 0x00
Aux0 errors 0,0,0
Step timer max interval 130
MCU temperature: min 38.5, current 41.3, max 41.4
Supply voltage: min 15.2, current 15.3, max 15.3, under voltage events: 0, over voltage events: 0, power good: yes
12V rail voltage: min 12.2, current 12.3, max 12.3, under voltage events: 0
Heap OK, handles allocated/used 99/4, heap memory allocated/used/recyclable 2048/142/96, gc cycles 0
Events: 0 queued, 0 completed
Driver 0: standstill, SG min 0, mspos 88, reads 30169, writes 17 timeouts 0
Driver 1: standstill, SG min 0, mspos 88, reads 30169, writes 17 timeouts 0
Driver 2: standstill, SG min 0, mspos 8, reads 30173, writes 14 timeouts 0
Driver 3: standstill, SG min 0, mspos 8, reads 30176, writes 11 timeouts 0
Driver 4: standstill, SG min 0, mspos 8, reads 30176, writes 11 timeouts 0
Driver 5: standstill, SG min 0, mspos 872, reads 30170, writes 17 timeouts 0
Date/time: 2022-08-16 21:50:35
Slowest loop: 9.24ms; fastest: 0.05ms
=== Storage ===
Free file entries: 9
SD card 0 detected, interface speed: 25.0MBytes/sec
SD card longest read time 3.2ms, write time 0.0ms, max retries 0
=== Move ===
DMs created 125, segments created 6, maxWait 199371ms, bed compensation in use: none, comp offset 0.000
=== MainDDARing ===
Scheduled moves 2, completed 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state 4
=== AuxDDARing ===
Scheduled moves 0, completed 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
=== Heat ===
Bed heaters 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamber heaters -1 -1 -1 -1, ordering errs 0
Heater 0 is on, I-accum = 0.0
=== GCodes ===
Segments left: 0
Movement lock held by Trigger
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is idle in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is doing "M400" in state(s) 0 0, running macro
Queue is idle in state(s) 0
LCD is idle in state(s) 0
SBC is idle in state(s) 0
Daemon is idle in state(s) 0
Aux2 is idle in state(s) 0
Autopause is idle in state(s) 0
Code queue is empty
=== CAN ===
Messages queued 1839, received 0, lost 0, boc 0
Longest wait 0ms for reply type 0, peak Tx sync delay 0, free buffers 50 (min 50), ts 1023/0/0
Tx timeouts 0,0,1022,0,0,815 last cancelled message type 30 dest 127
=== Network ===
Slowest loop: 16.75ms; fastest: 0.02ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions Telnet(0), 0 sessions
HTTP sessions: 1 of 8
- Ethernet -
State: active
Error counts: 0 0 1 0 0
Socket states: 5 2 2 2 2 0 0 2

@owend Thanks for your reply. I tried the M400 and also a G4 1000. But the result is the same, somehow the G1 instruction hangs up..

When it hangs up, the extruder motor is still energized, but it doesn't move anymore. The system status is "busy", and no other G-Codes are accepted.

Any idea what could be the reason?

Hello,
for the application described in this other topic I am trying to implement a simple speed controlled extruder using a Duet3.

What I tried to do, is to use a trigger (Extruder On command) to start a macro, and an analog input to set the desired extruder speed (as 0..100% of the G0/1 speed)

; config.g
...
...
M308 S3 P"io3.in" Y"linear-analog"  ; in3 is the speed ref
M950 J1 C"!io2.in"                  ; in1 is the start command
M581 T2 P1 S1 R0                    ; trigger 2 on in1-> trigger2.g
M571 P"io4.out" S1	            ; out4 is feedback "On"

The macro would continuosly execute small steps as long as the On Command is there, and between each step recalculate the speed and distance;

;trigger2.g

var REFSPEED=60		;reference speed in mm/min
var iterTime=1		;iteration time in s
var actSpeed=0		;calculated speed for this move in mm/min	
var actDist=0		;calculated distance for this move inmm

while sensors.gpIn[1].value = 1
	echo "speed scaling in % =", sensors.analog[3].lastReading
	set var.actSpeed = var.REFSPEED * sensors.analog[3].lastReading /100
	echo "speed in mm/min =", var.actSpeed
	;TODO: check the min-max limits
	set var.actDist =  var.iterTime * var.actSpeed / 60
	echo "distance in mm =", var.actDist

	G1 F{var.actSpeed} E{var.actDist}	
;end loop

It works for 5-6 rounds, but then the system hangs with the status "busy" and I have to reset the board.

Thanks for your help!

Well, it would be a shame to add another drive having 6 HC drives on the board..
Unfortunately I selected and bought the Duet3-6HC based more on the electrical requirements (motor power, temp sensors, FETs..), assuming that doing the SW-connection between an analog-in and the servo speed would be easier. I guess I overestimated my C++ skills

Can someone point me out how this connection could be implemented? Any input is welcome.

Basically, one analog in (temp or zprobe ? 0..10V would be ideal) should directly drive the extruder stepper speed (0..xxx rpm)
For all other settings I would use G-Codes over telnet

Thanks a lot!

@alankilian I see your point.
Well, the planned setup is simple. The ABB Robot, interprets the G-Codes commands (using ABB's 3DP Powerpack) and executes the movements. The synchronization between the robot and the extruder could be done using the TCP-speed (with configurable preset time, available as Analog Out or sent on ethernet using socket).
ABB's dispensing instructions would take care of handling the extruder activation/deactivation time to ensure proper synchronization.

On the Duet3 I would use the extruder stepper out, HotEnd temperature regulation, Hotbed temperature regulation and Fans.

My original plan was to feed the extruder speed directly using an analog input, and control the HotEnd/HotBed/Fans through G-Codes via ethernet.

What do you think about this concept?
As I understand an IO can be configured to read an analog in (for example for Z-probe), but how to bind this input to the extruder speed with minor FW changes (if any) on the Duet?

@alankilian: I set up the robot controller as socket client and could connect to the duet3, send G-Codes and get the answer.

As the movements are executed by the robot, whereas the extruder is controlled by the Duet3, If I forward all Exx and Fxx parameters over Telnet, do you think the transmission delay and refresh rate will have an impact on the synchronization and finally on the print quality?

Thanks a lot for your help!

Hello,
I plan to use a duet3 6HC togehter with a 6-axis ABB robot. In a first stage, the robot will be the "master" , reads the G-Code, plans and executes the trajectories, the duet3 controls the extruder and heatbed.

I planned to send G-Code commands as HTTP Requests from the robot to the Duet3, but unfortunately the HTTP protocol is not supported by the robot controller (only socket comm).

Plan B is to exchange the following signals between the duet3 and the robot:

Robot->Duet3:
Extruder Motor cmd On/Off - DI
Heatbed cmd On/Off - DI
Extruder Heating cmd On/Off - DI
Extrusion speed cmd - Analog In
Heatbed temp - Analog In
Extruder Heating temp - Analog In

Duet3->Robot
Temp Heatbed Ok -DO
Temp Extruder Ok - DO
Extrusion state On/Off - DO

The robot controller sets the heatbed + extruder temperature and gives the command to start heating, as soon as the feedback comes that the temperatures are ok, the robot can start moving and extruding by setting the corresponding Extrusion speed and extrusion On Command.

I would need 3 DI, 3 DO and 3 AI on the Duet3.

Any suggestion how to achieve this (or a better solution maybe?) with a minimum amount of FW changes?

Thanks
Giuliano

I copied libm from the GNU Arm Embedded Toolchain to one of the projects build folder (C:\Eclipse\Firmware\RRFLibraries\SAME70_RTOS) and added libm to the library list again as you suggersted and it works this way.
Not sure why the build process wasn't reading it from the original folder, although in the log i saw the entry:
attempt to open c:/program files (x86)/gnu arm embedded toolchain/10 2021.10/bin/../lib/gcc/arm-none-eabi/10.3.1/../../../../arm-none-eabi/lib/thumb/v7e-m+dp/hard\libm.a succeeded

You can close this thread i think.

Thanks a lot for your help

@dc42 Thanks for the hints. Adding libm didn't help, and through the --verbose command i have seen that the library succeeds loading in previous steps (?).

i don't really know what else I could try.. do you see anything suspect in my log?

Thanks
Giuliano

log.txt