Lift Counter using PIC12F629 Microcontroller

This project has been developed due to a request from Mr Moshweunyane ([email protected]). He asked for a circuit that would count up when someone entered a lift and count down when someone exited, using two infra-red sensors.
All we had to do was take the 2-digit up/down counter and add two optical sensors.
These sensors could be any type of detector and we have shown two LDR’s (Light Dependent Resistors) and two amplifying transistors mounted on a sub-board. You can use infrared or photo-transistors as the sensors to get equal results.
All the “detection” is done via the software and the program “polls” the detectors and works out if a person is entering or leaving the lift.

Lift Counter
The reason for polling the sensors is clever. It prevents the micro being caught in a loop and allows the program to display numbers at the same time.
The same design can be used for a shop or any activity where you need to know if a room is getting too crowded.
This arrangement has been requested for bathrooms in an attempt to control and avoid unsavory behavior.
The circuit is designed around a PIC16F628A. It has been presented on an experimental PC board using surface-mount components and was built in less than 1 hour, with about 2 hours to write and finalise the program.
It uses “In Circuit Programming” via PICkit-2 or Talking Electronics Multi-Chip Programmer, plus the adapter (specific to each programmer) shown below.
You can add an alarm feature if the lift gets overcrowded or if someone is in the bathroom when the shop is closing.

This project has been created as an add-on for the 2-Digit Counter. We placed the two transistors, LDR’s and pots on a small PC board and connected it to the 2-Digit Counter via a plug and socket.

READ  Test For Presence of Internal Oscillator Calibration Word for PIC12F629

The light detectors have to be set up for the application. The best is to use infra-red detectors as they are not upset by ambient light.
Each detector has to be set up so that light falling on the detector makes the input line LOW.
When the beam is broken, the line goes HIGH.
We have directly coupled the output of the detector to the micro however you could use capacitor coupling  and breaking the beam will produce a pulse.

The files for Lift Counter
LiftCounter-asm.txt (.asm)
LiftCounter-hex.txt (.hex)


For more detail: Lift Counter using PIC12F629 Microcontroller

Current Project / Post can also be found using:

  • 16f84a التحكم فى السرفو متور
  • lift circuit by 16f84 microcontroller
  • talking electronics multi chip programmer ebay
  • mạch đèn chạy đuổi dùng led

Leave a Comment

= 5 + 2

Read previous post:
Audio Spectrum Analyser
Audio spectrum analyzer using PIC18F4550

Introduction This project implements a real-time audio spectrum analyser using a PIC18F4550 8-bit microcontroller. The spectrum frequency analysis is performed...

Scroll to top