Pin Distribution

Description

• This page lists the pin distribution of the FLY-SB2040 Pro V3 tool board after flashing Klipper firmware. Pin numbers are based on the product schematic.
• UART/CS is the driver communication pin: it serves as UART when using TMC2240, and as chip select CS when using an SPI driver. The same pin is multiplexed.
• EN is the enable pin. In Klipper configuration, it is typically active low (enable_pin with a ! prefix).

Loading...

---

Interactive Pin Hotspots

The image below uses the FLY-SB2040 Pro 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.

Filter by deviceClick a device type to show only connectors that support it; click again to clear the filter.

FLY-SB2040 Pro V3Motor driversHeatersThermistorsFansEndstopsRGB

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	-

Power Off Before Operation

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

Supported Thermistor Types

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_type options 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