FOC Motor Controller for Bambulab Extruder Servo

The goal is to run Bambulab's proprietary extruder servo motor from the P2S 3D printer on Klipper-based 3D printers. Uses an ESP32 and a FOC driver to translate step/dir commands from standard printer mainboards (e.g. Manta M8P) into closed-loop FOC control.
Bambulab's extruder servo uses a proprietary interface. This adapter makes it work with any Klipper mainboard that outputs step/dir signals.

How it works: Klipper mainboard sends step/dir pulses to ESP32
ESP32 counts pulses using hardware PCNT and converts to target angle
SimpleFOC library drives the BLDC motor with closed-loop FOC control
MT6835 magnetic encoder provides position feedback

Quick Start

# Build and upload using platformio
pio run -e main -t upload

# Monitor serial output
pio device monitor -b 115200

Wiring Guide

Components

1. Bambulab Extruder Servo Motor, (FAM018) integrated MT6835 encoder
2. FFC Breakout Board, 20-pin, 0.5mm pitch
3. ESP32 Dev Board
4. BLDC Motor Driver 3PWM type (SimpleFOCMini, DRV8313)
5. Klipper Mainboard (e.g. Manta M8P)
6. 24V PSU

Bambulab Motor

Pin Connections

ESP32 to Motor Driver (PWM Control)

ESP32 Pin	Driver Pin
GPIO 32	IN1
GPIO 33	IN2
GPIO 25	IN3
GPIO 26	EN

ESP32 to MT6835 Sensor (SPI via FFC)

ESP32 Pin	FFC Pin	Function
GPIO 5	19	SPI CS
GPIO 18	16	SPI CLK
GPIO 19	18	SPI MISO
GPIO 23	17	SPI MOSI
3.3V	20	VCC
GND	13	GND

Klipper Mainboard to ESP32 Step/Dir Inputs

ESP32 Pin	Mainboard Pin
GPIO 13	Klipper STEP
GPIO 14	Klipper DIR
GND	GND

Motor Driver to BLDC Motor (via FFC)

Driver Pin	FFC Pins
OUT_U	1-4
OUT_V	5-8
OUT_W	9-12

Power Supply Connections

Power Supply	Component	Pin
+24V (PSU)	Driver	VM
GND (PSU)	Driver	GND
GND	ESP32	GND
+5V or USB	ESP32	VIN or USB