Pin Mapping
- This page lists the pin mapping of the FLY-SB2040 V3 toolhead board after flashing the Klipper firmware, based on the product schematic.
UART/CSis the driver communication pin: it acts as UART when using TMC2209, and as chip selectCSwhen using SPI drivers; the same pin is multiplexed.ENis the enable pin, typically active-low in Klipper configuration (enable_pinprefixed with!).
Interactive Pin Hotspots
The image below uses the FLY-SB2040 V3 product image and the same hotspot data from the Klipper configuration generator. Use the device filters above to show only compatible connectors; click a hotspot to see compatible devices, common Klipper configuration sections, and notes. Use “Locate in pin table” in the detail panel to jump to and highlight the corresponding row below. Hover still shows the connector name and pin. 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 | gpio14 | gpio13 | gpio16 | gpio15 | - |
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 |
|---|---|
| HV-IN / General Input | gpio22 |
| General Input 0 | gpio18 |
| General Input 1 | gpio20 |
For wiring of micro switches, optical endstops, proximity sensors, and TAP, see: Endstop Wiring Guide
Heating
| Function | Pin |
|---|---|
| Heater Port 0 | gpio23 |
Temperature Sensors
| Function | Pin |
|---|---|
| Thermistor Port 0 | gpio27 |
The thermistor ports support NTC thermistors (100K) by default, with sensor_type recommended as Generic 3950; they also support 2-wire PT1000, configured by setting sensor_type to PT1000.
List of
sensor_typeoptions that can be directly connected internally by Klipper and their applicable scenarios: Thermistor Configuration Method
K-type thermocouples, 3-wire PT100, etc., require additional signal conditioning chips and cannot be connected directly to the thermistor ports.
Fans
| Function | Pin |
|---|---|
| Fan Port 0 | gpio24 |
| Fan Port 1 | gpio19 |
| Fan Port 2 | gpio21 |
RGB
| Function | Pin |
|---|---|
| RGB / Neopixel | gpio26 |
PWM
| PWM Function | Pin |
|---|---|
| RGB / Neopixel | gpio26 |