An LED electronic safe box has an electronic lock installed in the door, which can be locked and unlocked by entering a specific code into the keypad. The LED displays the status of the electronic safe box and the contents input from the keypad.

This reference design features a small pin-count, low power RL78/G1N microcontroller that can directly drive high-brightness LEDs of 8 segments and 6 digits via large current output terminals. With a single microcontroller, you can realize 7-segment 6-digit LED display control, keypad control, motor control (electronic lock control), and buzzer control.

Disclaimer: THIS MATERIAL IS PROVIDED “AS-IS” FOR EVALUATION PURPOSES ONLY. RENESAS ELECTRONICS CORPORATION AND ITS SUBSIDIARIES (collectively, “Renesas”) DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. Renesas provides evaluation platforms and design proposals to help our customers to develop products. However, factors beyond Renesas' control, including without limitation, component variations, temperature changes and PCB layout, could significantly affect the product performance. It is the user’s responsibility to verify the actual circuit performance.


  • Demo board includes the RL78/G1N
  • 7-segment 6-digit LED display
    • Numbers: content input into the keypad
    • OPEΠEd (Opened): Electronic lock is unlocked
    • CLOSEd (Closed): Electronic lock is locked
    • HOLd15 etc: Password setting time
  • 10-key input
  • Electronic lock/unlock
  • Buzzer
  • Powered by 3 AA batteries (1.5V x 3)
  • Low power consumption operation 20uA(TYP.)@STOP mode


Design & Development

Sample Code

LED Electronic Safe Box

Renesas demonstrates the LED Electronic Safe Box quick solution featuring the RL78/G1N microcontroller.