• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

Question: Connecting 634 Reflective to COM Port


New member
I'll be mounting my 634 in a project box for portability.

I wish to build my own cable (wires, not ribbon) to go from my PC's COM Port to the LCD.

I want to use the J2 Header (.100) instead of J1 (DB9) on my LCD.

I understand DB9 Pin 5 will go to J2 Pin 1 for VSS (Ground).
I understand DB9 Pin 3 will go to J2 Pin 4 for Data_In.

My question is: Can I use either
DB9 Pin 4 (DTR) or
DB9 Pin 7 (RTS) or
Both for J2 Pin 2 (VDD)?

Or does J2 Pin 2 (VDD) _have_ to come from a separate +5V regulated source such as a fixed/floppy disk power connector?
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
USB LCD Displays - Graphic and Character LCDs with a Keypad