DoorChime

Parts required

  • ezeio controller
  • Motion sensor
    we’re using a standard PIR, Passive Infra Red, detector typically used for burglar alarms
  • Magnet contact with magnet
    this is also a common part in burglar systems. Some doors are pre-wired with a contact in the frame.
  • Sounder, Chime, Buzzer or Door bell
    may need a separate power supply if it require something else than 12VDC

Connections

Motion detector

Motion sensors for burglar alarm systems typically require 12VDC. The ezeio provides a suitable output on the terminal strip. When motion is detected, the sensor will activate a small internal relay that is usually wired as “nomally closed”. Thus, the contacts will break the connection between the relay terminals on the sensor.

This kind of output is directly compatible with the ezeio inputs. Normally (when no motion is detected) the ezeio input will be connected to 0V. When the motion detector relay opens, the pull-up resistor internal to the ezeio will make the voltage on the terminal rise to about 2.8Volts.

Magnet contact

The magnet contact do not require a supply voltage. The contacts can be directly wired to the ezeio 0V and one of the inputs. The ezeio internal pull-up resistor will ensure that when the magnet contact is open, a voltage is applied to the input just as for the motion detector.

Chime/Sounder

For our setup we used a $10 door bell from Home Depot. It requires 16VAC to work, and a transformer was included in the package, as was a pushbutton (that we won’t use) and a diode. We use one of the relay outputs on the ezeio to replace the push button. Other than that we followed the instructions for the door bell.

Verify connections

To make sure all the connections work as they should, navigate to the status page at ezecontrol.com and check the inputs.

  • Input 1 (the motion detector) should show close to zero Volt when there is no motion, and about 2800mV when it detects a human.
  • Input 2 (the magnet contact) should show close to zero Volt when the door is closed, and about 2800mV when the door is open.
  • Also try clicking the ON/OFF buttons for output 1 to make sure the sounder reacts.

Programming

Schedule – Office hours

First we need a schedule that is active during office hours. No actions are required on this schdeule as we’re only going to use it as a filter for the input actions on input 2 (see below).

Input 1 – Lobby Motion

All we need on this input is to set it in alarmed state when the motion detector trips. We also want to hold the alarm for a few seconds. This is easily set up with a holdoff time on restore, in this case 15 seconds.

Input 2 – Front door magnet

The magnet contact is the input that will trip the chime or the message. Start by setting up the input and one alarm with suitable thresholds. A 5 second holdoff on restore ensures there is no double trip if the door bounces.

Finally we need actions on this alarm to trip the chime, and to send messages on entry/exit.

Notice the condition fields. For alarm action 1, the output will only be activated if the schedule is active (during business hours) and the motion input is not in alarm – which means we’ll get a chime only if the door opens before the motion detector sees any motion.

Results

We have implemented a simple door chime system with email alarming capability. The chime is a bit unique in that it detects the direction of the person passing through the door, thus avoiding annoying extra chime signals. The system also automatically reverts to alarming mode during non-office hours, and alerts the owner if there is unexpected entries.