Keypad Access

Original doc by:

TechDesign Electronics



Dual programmable keypad code lock.

Open electrical doors with your secret code only!

Here are the technical specifications:

  • Up to two keypads may be connected to drive both relay outputs.
  • Professional, outdoor or other keypads may be used.
  • Relay outputs are configurable: output voltage +6 to +24VDC (from power input) or simple switch emulation.
  • The small LCD is optional, and can be omitted.
  • Low power operation with internal switching power regulator and microcontroller auto sleep mode: only 4 .. 8 mA at 12VDC
  • The 4-digit secret codes can be changed by the user (previous code needed.)
  • Auto blocking after 5 wrong attempts.
  • High-pitched piëzo sounds when striking a key.
  • Keypad cable length up to 100m.

  • This product will be available as a KIT from our online shop.
  • Source code (CCS C) can be purchased separately.

PIC hex file , pcb layout and schematics (Eagle) available. 

Last update: August 28, 2007.


Interface: Schematic & PCB: (right click & "save as" )



Interface: Main Connections:

PCB diagram

Header pinouts and connections


X1 Relay switched output 1
1 +6 to 24VDC (JP1 position: right) or switch_A (JP1 position: left)
2 Ground (JP2 position: left) or switch_B (JP2 position: right)
X2 Relay switched output 2
1 +6 to 24VDC (JP3 position: right) or switch_C (JP3 position: left)
2 Ground (JP4 position: left) or switch_D (JP4 position: right)
X3 Power input
1 +6 to +24VDC
S1 RESET circuit reset key (same as power down)
S2 BLANK short press: relay output test

long press (until beep) resets the secret codes to: (do a reset first)

  •  "4711" and "8411" for relay output 1
  •  "4722" and "8422" for relay output 2
U$1 LPH7779 Optional LCD connector (leave open when no LCD)
JP5 RS232 RS232 debug and bootloader (leave open for normal use)
JP6 RX433 Future wireless extension (leave open)
JP7 ANT Future wireless extension (leave open)
ST1 Keypad 1 connector
ST2 Keypad 2 connector

Instructions for use:


Downloads: right-click & save as

  WARNING: may not be duplicated for any commercial use whatsoever without explicit consent from the author (c) Michel Bavin, TechDesign Electronics.


 Eagle PCB layout: 545_10.brd  - August 14, 2007.

 Eagle Schematics: 545_10.sch  - August 14, 2007.

 Schematics GIF-image: 545_sch.gif  - August 14, 2007.

 Part List (bill of Materials: 545_v10_bom.htm  - August 14, 2007.


 PIC CCS example:Hex file: 545_v005.hex for 18f452 @ 20MhZ - August 28, 2007.



Info & datasheet:

Professional Storm keypads: 1K12T101-FEC



Circuit overview



The PIC code was made with the PCWH CCS compiler ($425,-); you can install Microchip's MPLAB IDE (click on the link and you can get it for free) with it to get things running smoothly.

Bootloading of the PIC18F452 can be done with the excellent Tiny PIC bootloader, through RS232

Eagle 4.11e was used for the schematic & PCB layout. 


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