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Pinout

Note
  • This page lists the pinout of the FLY-RPFMEX mainboard after flashing Klipper firmware. Pin numbers are based on the mainboard schematic.
  • UART is the TMC2209 driver communication pin.
  • EN is the enable pin. In Klipper configuration, it is usually active low (with ! prefix in enable_pin).
  • DIAG is the driver diagnostic signal pin. When using sensorless homing, configure the corresponding diag_pin according to the table below.
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Driver Pins

The FLY-RPFMEX provides 4 driver ports:

DriverSTEPDIRENUARTDIAG
DRIVER0gpio6gpio5gpio9gpio7gpio8
DRIVER1gpio1gpio0gpio4gpio2gpio3
DRIVER2gpio22gpio21gpio25gpio23gpio24
DRIVER3gpio17gpio16gpio20gpio18gpio19

DIAG and Sensorless Homing

The DIAG signals of DRIVER0–3 are independently and directly connected to the main MCU GPIOs. When using sensorless homing, configure diag_pin directly according to the DIAG pin in the driver table:

DriverDIAG / diag_pin
DRIVER0gpio8
DRIVER1gpio3
DRIVER2gpio24
DRIVER3gpio19

These DIAG pins are not the regular endstop ports in the "Endstops" table below. Enabling sensorless homing will not occupy the standard endstop inputs gpio27, gpio28, gpio29.

Endstops and Temperature Multiplexing

FunctionPinNotes
Endstop / ADC Shared Port 1gpio27Shared with Thermistor Port 1
Endstop / ADC Shared Port 2gpio28Shared with Thermistor Port 2
Endstop / ADC Shared Port 3gpio29Shared with Thermistor Port 3

Temperature Sensors

FunctionPinNotes
Thermistor Port 1gpio27Shared with Endstop / ADC Shared Port 1
Thermistor Port 2gpio28Shared with Endstop / ADC Shared Port 2
Thermistor Port 3gpio29Shared with Endstop / ADC Shared Port 3
Power Off Operation

Before starting, completely turn off the printer and disconnect the power supply. Do not plug or unplug wiring harnesses, organize interface wiring, or touch terminals while the system is powered on.

Interface Multiplexing

gpio27, gpio28, and gpio29 support both general-purpose input and ADC sampling functions, but can only be used for one purpose at a time. After configuring them as thermistor inputs, do not configure the same interface as a mechanical endstop or other input. On the left side of the interface diagram, from top to bottom, the pins are gpio29, gpio28, gpio27. Please verify according to the actual wiring order.

Supported Thermistor Types

The thermistor ports support NTC thermistors (100K) by default. The recommended sensor_type is Generic 3950.

List of built-in sensor_type options accessible directly in Klipper and their applicable scenarios: Thermistor Configuration Method

K-type thermocouples, PT100, etc., require additional signal conversion chips and cannot be connected directly to the thermistor ports.

Fans

FunctionPinNotes
Fan 0gpio11Controllable output
Fan 1gpio12Controllable output
Fan 2-Always-on power port, not controlled by MCU

General Purpose Input

FunctionPinNotes
HV-IN / General Purpose Inputgpio10Input port, not used as RGB output

PWM

PWMPinNotes
PWM0gpio11Fan 0
PWM1gpio12Fan 1

Screen / EXP Notes

Interface Notes

The FLY-RPFMEX does not provide standard EXP1 / EXP2 12864 pin headers. Please use the driver, endstop, temperature, fan, and general-purpose input interfaces listed on this page. Do not apply the EXP1 / EXP2 pinout tables from other mainboards.

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