home mailbox sensor

This is my first IOT project. There are home mailbox sensor lots of room for improvement. For example, the time of day when a mailbox is opened could be used to make the sensor more efficient. The sensor can be dormant at night. The sensor and particle photon could be housed in a well designed box.

I look forward to creating cool home automation based projects in the future.

Stay tuned.

mail box sensor on our site!
I normally check my mailbox (snail mail) wireless mailbox sensor every day before entering my apartment. One day I thought “Wouldn’t it be nice if I know if I have new letters without having to check the mailbox?” That’s how I came up with the idea to install a wireless sensor that will notify me when somebody leaves something from me in the mailbox.

The idea itself it’s nothing new and it’s very common among Arduino enthusiasts. What I think is unique is the combination of tools I used (or at least I couldn’t find a similar solution to the setup I have).

In this posts I will just describe the wireless mailbox sensor. It’s basically one home-made Arduino (you can see this post on how you can build your own one) with an Xbee Series 1 transmitter and a couple of sensors: A DFRobot DFR0028 Tilt Sensor and a http://www.mailboxsensor.com Snap-Action switch (similar to this one).
The tilt sensor will detect when a new letter arrives and it’s placed in the small cover of the mailbox. It will trigger when the mailbox lid is lifted. Originally I thought of having a light sensor in there, but it was just easier to have an on-off sensor because I only need to recognize these two states. The snap-action switch will detect when I open the mailbox with the key (to reset the detection) and it’s placed right where the lock mechanism is resting. The snap-action switch is normally closed and when I use the key and rotate the lock mechanism, the switch will open, thus triggering the sensor. Every time a sensor is triggered, the Arduino will send a message to the coordinator (i.e. another Arduino I have in my apartment also with an Xbee attached).

The power source

I started my prototype based on this post from the adafruit forum. It also provided me with a solution to run the sensor on batteries. Originally I had no idea how to deal with that. The simple setup should not consume a lot of power, but the Xbee could, so the idea from this guy was to cut the Xbee power when it’s not sending anything, and only power it up when you need to send something (BTW, that implies one-way communication, which I don’t like since I want to be able to reset the mailbox not only with the key, but also remotely, but I will try to achieve this on a further version of the sensor).