Pinout
- This page lists the pinout of the FLY-MMU tool board after flashing Klipper firmware. Pin numbers are subject to the product schematic.
UART/CSis the driver communication pin: used as UART with TMC2209, or as chip selectCSwith SPI drivers; the same pin is multiplexed.ENis the enable pin. In Klipper configuration, it is typically active low (with!prefix inenable_pin).
Interactive Pin Hotspots
The image below uses the product image of FLY-MMU and the same hotspot data. Use the device-type filters to show only compatible connectors; click a hotspot to see which devices it accepts, common Klipper configuration options, and notes. Hover to see the connector name and pins; always verify the silkscreen and connector positions against the physical board and schematic.

Hover to see the pin; click a hotspot to view compatible devices and configs. Pins can be copied from the detail panel, except for driver connectors.
Driver Pins
| Driver | STEP | DIR | EN | UART/CS | Endstop |
|---|---|---|---|---|---|
| DRIVER0 | PE14 | PE13 | PE12 | PE11 | - |
| DRIVER1 | PC5 | PB1 | PB0 | PE7 | - |
| DRIVER2 | PC4 | PA6 | PA7 | PA5 | - |
| DRIVER3 | PE4 | PE6 | PE5 | PC13 | - |
Before starting, completely shut down the printer and disconnect the power supply. Do not plug or unplug wiring harnesses, organize interface wiring, or touch terminals while the power is on.
Endstops
| Function | Pin |
|---|---|
| Endstop 0 | PD3 |
| Endstop 1 | PD4 |
| Endstop 2 | PD5 |
| Endstop 3 | PD6 |
| Endstop 4 | PD7 |
| Endstop 5 | PC0 |
| Endstop 6 | PC1 |
| Endstop 7 | PC2 |
| Endstop 8 | PC3 |
| Endstop 9 | PE3 |
| Endstop 10 | PE2 |
For wiring of micro switches, optical endstops, proximity sensors, and TAP, see: Endstop Wiring Guide
Servos
| Function | Pin |
|---|---|
| Servo 0 | PA3 |
| Servo 1 | PA2 |
| Servo 2 | PA1 |
| Servo 3 | PA0 |
RGB
| Function | Pin |
|---|---|
| RGB | PE10 |
| TP LED / Neopixel | PA8 |
Fans / Expansion Outputs
| Function | Pin |
|---|---|
| FAN0 | PA0 |
| FAN1 | PA1 |
| FAN2 | PA2 |
| FAN3 | PA3 |
PWM
| PWM Function | Pin |
|---|---|
| Servo 0 / FAN3 | PA3 |
| Servo 1 / FAN2 | PA2 |
| Servo 2 / FAN1 | PA1 |
| Servo 3 / FAN0 | PA0 |
| RGB | PE10 |
| TP LED / Neopixel | PA8 |