Parallel Port Breakout board with Buffer for CNC & Routers

Parallel Port Breakout board
Rajkumar Sharma


Parallel port I/O break out board designed for Hobby CNC, Routers and Motion controller , This Board is an easy solution to driver stepper Motor driver, AC Servo (with Step-DIR Driver) and DC servo (with Step-DIR Driver), The Board is compatible with various CNC software specially made for LPT port data out. The board has been tested with MACH3 CNC software. All outputs are buffered, all inputs are optical isolated and can be used as emergency switch, limit switch and home switch.

The board has 12 output pins that can control various devices such as stepping motor drivers, AC Servo Driver, DC Servo Driver, Plasma Torch, Pump for coolant, spindle, 5 Input pins are provided for limit or home switches, feedbacks, Emergency switch. All inputs has 470E for current controlled and TTL Voltage input required driving the inputs. This board can be powered with USB input or DC input supply 7V to 36V, keep jumper J2 open in case of USB supply input. Board has Screw Terminals for Inputs and out connections and also provided with 4X6Pin header connecters for outputs. J15 is connected directly to parallel port pins for testing purpose.

Note: For 24V input signal replace of R3, R4, R5, R6, and R7 with 2K2 Ohms.

Supply 7V to 36V DC
25 D SUB Female Connecter for PC LPT Port Interface
On Board Power LED
On Board USB Connector for Supply from PC or other USB source
Jumper Selection for USB Supply Input or External Supply
All Outputs are buffered
All inputs are optically isolated
Two Options for Outputs, Screw Terminals and Header Connectors
4X6Pin Header for easy motor driver interface
On Board L317 Regulator for 5V DC
Heat sink for regulator
5V DC Output for External Circuits
3X3 Header Connector for Relay Driver for Spindle, Plasma, Laser, Pump ON/OFF


CN15 : LPT Port Test Pins
CN7 : Inputs , Limit Switch, Feedback, Home Switch, Emergency Switch
CN1 : DC Supply Input 7V to 36V
CN2 : DC 5V Output
CN10, CN11, CN12, CN13 : Header Connector for Stepper driver Interface
CN8, CN9, CN14 : 3X3Pin Header Connector to driver Relay for Outputs
CN5 : Outputs
J3 : E Stop Optional Jumper for Test Purpose
J4, J5 : I/O Direction Control ( Jumper Close to VCC for Normal Operation)
CN6 : USB Connecter for VCC Supply input ( Keep Jumper J1 Open for USB Supply Input)
D1: Power LED

For more detail: Parallel Port Breakout board with Buffer for CNC & Routers

About The Author

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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