Alternatively, I could imagine a fully modular "core" Duet3 board that has only Ethernet/Wifi, control interface IO (LCD/I2C/...) and CAN-FB on it and everything else is connected using various types of tool boards:

• a N * "stepper driver + end stops"
• a N * "temp out + temp sensor"
• a "hot end combo" [the existing one]
• a N * pwm fan + GPIO

That way, people could only pay for what they need at the time, mix and match what is needed (need 20 drivers? just add more tool boards) and upgrade/reuse as time goes on (new features only require new tool boards, not a new core board, or a faster processor/more oompf just needs a new core, but the periphery stays the same)... you get the drift.

Then switch to RJ45 for CAN-FB, because those come in twisted pair and are dirt cheap (which cannot be said for RJ11)

Alternatively, I could imagine a fully modular "core" Duet3 board that has only Ethernet/Wifi, control interface IO (LCD/I2C/...) and CAN-FB on it and everything else is connected using various types of tool boards:

• a N * "stepper driver + end stops"
• a N * "temp out + temp sensor"
• a "hot end combo" [the existing one]
• a N * pwm fan + GPIO

That way, people could only pay for what they need at the time, mix and match what is needed (need 20 drivers? just add more tool boards) and upgrade/reuse as time goes on (new features only require new tool boards, not a new core board, or a faster processor/more oompf just needs a new core, but the periphery stays the same)... you get the drift.

Then switch to RJ45 for CAN-FB, because those come in twisted pair and are dirt cheap (which cannot be said for RJ11)

Sounds interesting, but that is probably not what I was referring to...

If you use the tools board(s) for your extruder(s), you still need the three stepper drivers for X/Y/Z movement, but you don't need the hotend components (i.e. extruder drivers, head temp probe, head heater out, head fans, z-probe, ...), so the board could be simplified quite a bit.

The board basically still needs "the rest".

The Duet3 with it's $300 price tag is a substantial chunk of cash, so anything to reduce the price would be welcome.

Are there any plans to make a "lite" version of the Duet 3 board for people only planning to use the CAN-FD port for hotend(s)?

There is a lot of (costly) hardware on the Duet3 that is not relevant if using a CAN-FD type setup.

@DIY-O-Sphere It's not fans, it's heaters and showing tools instead of heaters in a temperature chart is a bad idea, because there isn't necessarily one heater for one tool (a tool could have 2 or more heaters or none).

@SIam You can still switch (by clicking on the blue "Bett" or "Werkzeug 0"), but it is highly annoying

@wilriker Sure, here you go:
Board: Board: Duet Ethernet 1.04
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.0 (2020-01-03b3)
DWC: Duet Web Control 2.0.4

Sanitized config.g:

; Drives
M569 P0 S0                              ; physical drive 0 goes backwards (X)
M569 P1 S0                              ; physical drive 1 goes backwards (Y)
M569 P2 S1                              ; physical drive 2 goes forwards (Z)
M569 P3 S0                              ; physical drive 3 goes backwards (E0)
M584 X0 Y1 Z2 E3                        ; set drive mapping
M350 X16 Y16 Z16 E16 I1                 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 E450.00       ; set steps per mm
M566 X900.00 Y900.00 Z120.00 E120.00    ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z1800.00 E1200.00; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00     ; set accelerations (mm/s^2)
M906 X600 Y800 Z800 E800 I30            ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                        ; set axis minima
M208 X300 Y300 Z400 S0                  ; set axis maxima

; Endstops
M574 X1 S1 P"!xstop"
M574 Y1 S1 P"!ystop"
M574 Z1 S1 P"!zstop"

; Z-Probe
M558 P0 H5 F120 T6000                   ; disable Z probe but set dive height, probe speed and travel speed
M557 X20:280 Y20:280 S65                ; define mesh grid
G29 S1                                  ; read mesh grid from file

; Heaters
M308 S0 P"bedtemp" Y"thermistor" A"Bed" T100000 B4138 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0                          ; create bed heater output on bedheat and map it to sensor 0
M143 H0 S120                                   ; set temperature limit for heater 0 to 120C
M307 H0 B0 S1.00                               ; disable bang-bang mode for the nozzle heater and set PWM limit
M308 S1 P"e0temp" Y"thermistor" T100000 B4138  ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1                           ; create nozzle heater output on e0heat and map it to sensor 1
M143 H1 S280                                   ; set temperature limit for heater 1 to 280C
M307 H1 B0 S1.00                               ; disable bang-bang mode for the nozzle heater and set PWM limit

; Fans
M106 P0 S0 I0 F500 H-1                  ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S0 I0 F500 H-1                  ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H1 T45               ; set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F1                        ; define tool 0 -> using FAN 1 (fritzed Fan 0)
G10 P0 X0 Y0 Z0                         ; set tool 0 axis offsets
G10 P0 R0 S0                            ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined
M912 P0 S-3.2                           ; Calibrated MCU Temperature (reading is 3.2° too high)

; Miscellaneous
M501                                    ; load saved parameters from non-volatile memory

config-override.g

M307 H0 A476.5 C791.3 D4.8 S1.00 V23.9 B0
M307 H1 A1167.0 C239.9 D8.4 S1.00 V23.5 B0

@deckingman if you look at my screenshot and post, you can see what I configured. Using the latest available 3.0 firmware bundle from github.

@pipersw That is literally what I just wrote

@deckingman If you look carefully at the OP image, you can see that the names are wrong (heater 1, heater 1, heater 2 instead of heater 1, heater 2, heater 3)

Actually, on RRF3, if you rename a heater (using M308), it fails to display correctly:

Config:

M308 S0 P"bedtemp" Y"thermistor" A"Bed" T100000 B4138
M308 S1 P"e0temp" Y"thermistor" T100000 B4138

Display: