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Mainboard

Metric Value
SoC AllWinner R528-S3
Memory 128 MB in-chip
Storage 8gb eMMC
Stepper drivers tmc2209
Front Back
Mainboard image Mainboard back image
Credit to the Elegoo discord. Credit to thijskunst on the OpenCentauri Discord.

Mainboard Pins

24V input

Type: 2-Pin Barrier terminal with 9.6mm pin pitch

pin nr marking Function remarks
1 - GND Closest to the stepper connectors
1 + +24V Do not overtighten as it is very flimsy

Steppers X,Y and Z

Type: JST-XA-4P

pin nr marking Function remarks
1 2B 2B
2 1A 1A
3 2A 2A
4 1B 1B

Filament sensor

Type: JST-XA-3P

pin nr marking Function remarks
1 S Signal 3.3v when filament is detected
2 - GND
3 + +5V

Chamber temp sensor (marked "BOX-T" on the board)

Type: JST-XA-2P

pin nr marking Function remarks
1 none Sig standard NTC100k B3950
2 none GND

Light

Type: JST-XA-2P

pin nr marking Function remarks
1 + +24V Max 1A
2 - GND_PWM

Side fan (Marked "FAN-1" on the board)

Type: JST-XA-2P

pin nr marking Function remarks
1 + +24V MAX 1A
2 - GND_PWM

Rear exhaust Fan (marked "BOX-F" on the board)

Type: JST-XA-2P

pin nr marking Function remarks
1 + +24V MAX 1A
2 - GND_PWM

Camera

Type: JST-XA-4P

pin nr marking Function remarks
1 GND GND regular usb port but with a JST connector
2 DP USB-DP
3 DM USB-DM
4 5v +5V

UART0

Type: JST-XA-2P + 4-Pin 2.54mm pin header

pin nr marking Function remarks
JST:
1 TX RS232-TX connected to 4-pin header
2 RX RS232-RX

4-Pin Header:

pin nr marking Function remarks
1 GND GND square pad
2 TX RS232-TX
3 RX RS232-RX
4 5v +5V J4 marking

Multicolor

Type: JST-XA-5P

pin nr marking Function remarks
1 24V +24V 24v for motors inside the MMU
2 GND GND
3 5V +5V 5v can be turned off to reset MCU in the MMU
4 DM USB-DM standard usb 2.0
5 DP USB-DP

USB-C --> Extruder Board

Type: USB-C (USB 2.0 only)

Warning

Do not plug in anything other than the extruder board. this type-C connector has 24v vcc instead of 5v. Anything you plug in WILL GET FRIED!!

pin nr marking Function remarks
A1 no markings GND
A2
A3
A4 24V! VCC Switched 24V
A5
A6 USB 2.0 DP
A7 USB 2.0 DM
A8
A9 24V! VCC Switched 24V
A10
A11
A12 GND

Display

Type: xx Pin FFC

RGB888 display + touch\ unknown pinout

Front USB

Type: USB-A

pin nr marking Function remarks
1 GND GND regular usb-A port
2 DP DP
3 DM DM
4 5v +5V

Z-endstop (Marked "EXT" on the board)

Type: JST-XA-3P

pin nr marking Function remarks
1 +24V
2 GND
3 SIG 3.3V pullup, LOW/0v when bed is not in sensor

Mainboard fan "BFAN"

Type: JST-XA-3P

pin nr marking Function remarks
1 +24V
2 GND_PWM Controlled by MCU
3 Tacho

Bed MCU (RS-232)

Type: JST-XA-5P

pin nr marking Function remarks
1 24V +24V Not used on the leveling mcu board
2 GND GND
3 5V +5V 5v is switched to reset the bed MCU
4 TX TX
5 RX RX

Bed heater "HBED"

Type: JST-XA-2P

pin nr marking Function remarks
1 - GND_PWM Controlled by MCU
2 + +24V

Bed temperature sensoor "BED-T"

Type: JST-XA-2P

pin nr marking Function remarks
1 SIG NTC100k B3950
2 GND