The (also known as the Creality 2.2.1 or Atmega 2560 board) is a robust 8-bit control board famously used in larger-format printers like the CR-10S , Ender 5 Plus , and CR-20 Pro . Unlike the 32-bit V4 series found in the Ender 3 V2, this board is built on the Atmel AVR Atmega 2560 architecture, offering more I/O pins for dual extrusion and accessory support. Key Technical Specifications

Before any wiring mod, verify your board revision and cross-reference at least two community diagrams from GitHub or r/ender3.

microcontroller, it is frequently chosen for its "silent" operation when equipped with TMC2208 stepper drivers , significantly reducing motor noise. TH3D Studio LLC Core Specifications & Features Processor: 8-bit Atmel ATmega 2560. Stepper Drivers:

Houses the Micro USB port , LCD Screen ports (EXP1, EXP2, EXP3), and endstop connections for X, Y, and Z axes.

[USB Port] [MicroSD] [Reset Button] | | | [LCD EXP3] [LCD EXP2] [LCD EXP1] — to Ender 3 V2 Screen | [E Power In] (24V DC) - Fuse F1 (15A) | [Hotbed Out] (MOSFET controlled) | [Heater Out] (Hotend cartridge) | [Fan0 (Part Cooling)] - PWM capable [Fan1 (Hotend Fan)] - Always on when heater active [Fan2 (Controller Fan)] - Optional | [X-Motor] [Y-Motor] [Z-Motor] [E-Motor] (4x TMC2208 in standalone) | [X-Stop] [Y-Stop] [Z-Stop] (Mechanical endstops - 3 pins each: GND, SIG, VCC) | [Thermistor TH0 (Hotend)] [Thermistor TH1 (Bed)] | [Probe Port] (5 pin: GND, VCC, PA1_SERVO, PB7_PROBE, GND) | [Filament Runout Sensor] (2 pin)

| Feature | Specification | Diagram Accuracy | |--------|----------------|------------------| | | STM32F103RET6 (or clone GD32F303) | ✅ Correctly labeled | | Drivers | TMC2208 (standalone, no UART) | ⚠️ Diagram doesn’t show missing UART | | Probe port | 5-pin (G, V, IN, G, OUT) | ✅ Correct pins, but polarity missing | | Firmware flash | MicroSD card or ST-Link via SWD | ❌ SWD pins not on diagram | | Heater outputs | MOSFET-controlled (24V) | ✅ Marked | | Fans | Part-cooling (PWM), Hotend (always-on) | ⚠️ Fan0/Fan1 swapped in some revisions |

Features specialized pins often used for LED strips (EZNeo) or BL-Touch sensors. Wiring for Accessories