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MKS Robin Nano V3 Controller Board

See Owner-Reported Hardware and Test Status for the confirmed V3.0 hardware, connections and remaining checks.

The MKS Robin Nano V3 is the main controller board used by the My-Cloner Rev A.

It controls the printer's:

  • Stepper motors
  • Stepper drivers
  • Hotend heater
  • Heated bed
  • Temperature sensors
  • Cooling fans
  • Probe and auxiliary sensors
  • Display interfaces

The board communicates with the Raspberry Pi Zero 2 W running Klipper.

My-Cloner Rev A

The My-Cloner Rev A uses the MKS Robin Nano V3 with a 24 V DC system supply and 5 × TMC2209 stepper drivers.

The Raspberry Pi Zero 2 W is powered separately through a 24 V → 5 V LM2596 converter.

Official References

The information on this page is based on the official Makerbase and Klipper project files.

The official Makerbase schematic identifies the board as MKS Robin Nano V3, hardware revision V3.0_004, using an STM32F407VGT6 microcontroller.

Main Controller

Item Specification
Controller MKS Robin Nano V3.0 — owner-confirmed revision
MCU STM32F407VGT6
Firmware Klipper
My-Cloner system voltage 24 V DC
Stepper driver positions 5
Driver positions X, Y, Z, E0, E1
My-Cloner drivers TMC2209
Driver communication UART
Host Raspberry Pi Zero 2 W
Host communication USB
Primary UI Mainsail

The board-level schematic separates the controller into functional blocks for:

  • MCU
  • Power
  • MOSFET outputs
  • Thermistors
  • Endstops and sensor inputs
  • Stepper drivers
  • USB
  • SD card
  • Display / auxiliary connections

Stepper Driver Interfaces

The MKS Robin Nano V3 provides five replaceable stepper-driver positions:

Driver Position My-Cloner Rev A assignment
X X Axis
Y Y Axis
Z Left Z Axis
E0 Extruder
E1 Right Z Axis

The My-Cloner Rev A uses TMC2209 drivers in UART mode.

Rev A Assignment

Using the E1 driver for the second Z motor is a My-Cloner-specific assignment.

It must be physically validated during machine bring-up.

STEP / DIR / ENABLE Pins

Driver STEP DIR ENABLE
X PE3 PE2 PE4
Y PE0 PB9 PE1
Z PB5 PB4 PB8
E0 PD6 PD3 PB3
E1 PD15 PA1 PA3

The official Klipper generic configuration confirms the X, Y, Z and E0 mappings above and provides the E1 interface as an additional driver channel.

The final Klipper configuration may use the ! prefix to invert the direction or enable signal where required.

TMC2209 UART

The MKS Robin Nano V3 provides dedicated UART signals for the five stepper-driver positions.

Driver UART Pin
X PD5
Y PD7
Z PD4
E0 PD9
E1 PD8

These pins will be used by the corresponding Klipper [tmc2209 ...] sections.

Example:

[tmc2209 stepper_x]
uart_pin: PD5

Driver Configuration

The UART pin identifies the board connection only.

Motor current, StallGuard threshold and other TMC2209 parameters must be configured for the actual My-Cloner motors and validated on the physical machine.

DIAG and Endstop Interfaces

The MKS Robin Nano V3 provides DIAG routing for compatible TMC drivers.

The official board schematic maps the available driver DIAG signals to endstop inputs.

Driver DIAG / Endstop Input MCU Pin
X X- PA15
Y Y- PD2
Z Z- PC8
E0 Z+ PC4
E1 E1- PE7

For the My-Cloner Rev A:

  • X uses TMC2209 sensorless homing through X- / PA15
  • Y uses TMC2209 sensorless homing through Y- / PD2
  • Z uses P.I.N.D.A. V1 on Z- / PC8

The X/Y sensorless-homing architecture and the Z probe assignment are Rev A design assignments.

Motor current, StallGuard sensitivity, homing speed, repeatability, P.I.N.D.A. trigger polarity and probe offsets remain pending physical validation.

The X/Y sensorless homing configuration requires physical tuning and is not considered validated until it has been tested on the machine.

Heater Outputs

The board provides separate MOSFET-controlled outputs for the hotend, heated bed and an additional heater channel.

The official schematic exposes HEATER1, HEATER2 and HOTBED outputs.

Board Output MCU Pin My-Cloner Rev A
HE0 PE5 Hotend Heater
HE1 PB0 Not currently used
H-BED PA0 Heated Bed

The generic Klipper configuration confirms PE5 for the primary hotend heater and PA0 for the heated bed.

24 V System

The My-Cloner Rev A uses 24 V heaters.

Always verify heater voltage and wiring before power is applied.

Temperature Sensor Inputs

The MKS Robin Nano V3 provides three thermistor inputs.

The Makerbase schematic identifies:

  • TH1
  • TH2
  • TB
Input MCU Pin My-Cloner Rev A
TH1 PC1 Hotend Thermistor
TH2 PA2 Available
TB PC0 Heated Bed Thermistor

The generic Klipper configuration uses:

Hotend: PC1
Heated Bed: PC0

Thermistor Type

The MCU input pin and the Klipper sensor_type are separate settings.

The hotend sensor is owner-identified as ATC Semitec 104GT-2. The original Ender 3 bed sensor is NTC 100 kΩ, but its exact curve remains TBD.

Fan Outputs

The MKS Robin Nano V3 provides two controllable fan outputs.

Output MCU Pin My-Cloner Assignment
FAN1 PC14 4010 hotend cooling — Rev A assignment
FAN2 PB1 5015 part-cooling — Rev A assignment

These output assignments are specific to the My-Cloner Rev A. PWM behaviour and fan operation remain pending validation.

The official Klipper generic configuration uses PC14 as its example [fan] output and lists PB1 as the second fan output.

Probe and Auxiliary Inputs

The MKS Robin Nano V3 exposes several inputs that may be used by probes and auxiliary sensors.

Function MCU Pin My-Cloner Use
X Endstop / X DIAG PA15 X sensorless homing
Y Endstop / Y DIAG PD2 Y sensorless homing
Z Endstop / Z DIAG PC8 P.I.N.D.A. V1 on Z-; Z sensorless homing not used
Z+ / E0 DIAG PC4 Available
E1 DIAG PE7 Available
MT_DET1 PA4 IR V0.4 filament sensor
MT_DET2 PE6 Available
Power Detect PA13 Not currently implemented
Power Off PB2 Not currently implemented
BLTouch Control PA8 Not currently assigned

P.I.N.D.A. Probe

The My-Cloner uses a P.I.N.D.A. probe, not a BLTouch.

The owner reports P.I.N.D.A. V1 connected to Z- / PC8, GND and 5 V. Trigger polarity and offsets in the new Klipper configuration remain pending validation.

The BLTouch control pin must not automatically be treated as the P.I.N.D.A. input.

Filament Sensor

The My-Cloner Rev A uses an MK3-style IR filament sensor.

The MKS Robin Nano V3 provides two material-detection inputs:

Input MCU Pin
MT_DET1 PA4
MT_DET2 PE6

The My-Cloner Rev A assigns MT_DET1 / PA4 to the IR V0.4 filament sensor. See the I/O Map for assignment status and validation details.

EXP1 / EXP2 Headers

The board provides two display / auxiliary headers.

EXP1

Header Pin MCU / Signal
EXP1_1 PC5
EXP1_2 PE13
EXP1_3 PD13
EXP1_4 PC6
EXP1_5 PE14
EXP1_6 PE15
EXP1_7 PD11
EXP1_8 PD10
EXP1_9 GND
EXP1_10 5 V

EXP2

Header Pin MCU / Signal
EXP2_1 PA6
EXP2_2 PA5
EXP2_3 PE8
EXP2_4 PE10
EXP2_5 PE11
EXP2_6 PA7
EXP2_7 PE12
EXP2_8 RESET
EXP2_9 GND
EXP2_10 3.3 V

These mappings are also defined by the official Klipper board aliases.

The MKS TS35 V2.0 integration with the final Klipper system is pending validation.

Mainsail remains the primary user interface for the My-Cloner Rev A.

USB Communication

The My-Cloner uses USB communication between:

Raspberry Pi Zero 2 W → USB → MKS Robin Nano V3

The official Klipper generic configuration specifies:

  • MCU: STM32F407
  • Bootloader: 48KiB
  • Communication: USB

It also notes that the normal make flash procedure is not used for this board. Instead, the compiled Klipper binary is renamed to:

Robin_nano_v3.bin

and flashed using an SD card.

Firmware Installation

The complete firmware compilation and flashing procedure will be documented separately in the Firmware Configuration section.

Board Power

The official Makerbase pin map identifies the MKS Robin Nano V3 main supply as 12/24 V compatible.

The My-Cloner Rev A operates exclusively from:

24 V DC

The controller receives its 24 V supply from the Mean Well LRS-350-24.

The Raspberry Pi is not powered directly from the controller board in the current My-Cloner architecture.

Instead:

24 V DC → LM2596 → 5 V DC → Raspberry Pi Zero 2 W

My-Cloner Usage Summary

Board Function My-Cloner Rev A
X Driver X Axis TMC2209
Y Driver Y Axis TMC2209
Z Driver Left Z TMC2209
E0 Driver Extruder TMC2209
E1 Driver Right Z TMC2209
HE0 24 V Hotend Heater
HE1 Unused
H-BED 24 V Heated Bed
TH1 Hotend Thermistor
TH2 Available
TB Heated Bed Thermistor
FAN1 4010 hotend cooling — PC14
FAN2 5015 part-cooling — PB1
X- X Sensorless Homing
Y- Y Sensorless Homing
P.I.N.D.A. V1, Z- / PC8; GND and 5 V reported
MT_DET1 IR V0.4 filament sensor — PA4
EXP / Display TS35 V2.0 — integration: Pending validation
USB Raspberry Pi / Klipper communication