Mail delivery indicator

[TekGod]

I am trying to figure out how to make a simple circuit that I can install into my mailbox that will allow me to see from my house if the mail has been delivered. Ideally, it would involve a switch that activates an LED when the door was opened, and would require a reset action when I retreived the mail out of the box. It would be nice to have it powered by a 9v battery or something equally space conserving. Any ideas? Any solutions? All help will be grealy appreciated...

Thanks,

Chase

 

[tunedwolf]

It sounds like the perfect project for a 10F PIC micro, a low voltage drop regulator, a couple of caps, an LED and a lever micro switch...
The PIC just sleeps until the door is opened, wakes up and burst pulses the LED a couple of times per sec say every ten or fifteen secs. When the door is opened and closed again, it resets and waits until it's opened again...
Of course you would need to write the firmware for the PIC to do this...
And I can see it being a great game for the local kiddies once they figure out that you're out there with the slippers on every time ya see it blinking

 

[audioguru]

Can you see an LED blinking at your mailbox in the daylight?
I think you must wait for night-time to see it.

 

[HarveyH42]

Here's a wireless device for $25...

https://www.goldmine-elec-products.com/prodinfo.asp?number=G15451

Don't know how far away your mailbox is from the house, but you would need a very bright LED to see clearly in daylight, which would kill a 9 volt battery kind of quickly. Couldn't a flip-flop type circuit be used instead of a PIC? But then again, that would only tell you if the door was opened, not if there was actually any mail left in the box.

 

[tunedwolf]

of course...the entire circuit can be located in the house/garage with just the switch wires going to the mail box...

The rf solution is interesting also, but I'm guessing it's only sending a signal when the tilt switch swings down on the door, and there is no mention on the receiver latching the activation...

Yes, there are plenty of other ways to perform this task, a simple relay, an LED and a resistor, but the disadvantage is the power consumed, a pp3 battery will last diddly squat time...Simple CMOS could also be used with a push button reset for instance, with slightly better power requirements, but using any sort of small micro will minimise the current drawn and can be in direct control over how much current is stolen by the LED by means of a cyclic, duty factor based indication.

 

[The Mad Professor]

Sometimes the simplest solution really is a switch. I would look at a microswitch with a long flexible lever action, as for power perhaps something similiar to the ever so common solar powered garden lights seems apt. Signaling the house could be performed by a variety of methods.. how about a simple LC oscillator tuned up around a quiet spot on FM band

 

[tunedwolf]

RF in the commercial bands is not only illegal, but just bound to irk somebody living nearby...I do however like your idea of a solar garden light for the power supply

 

[denikar]

If you can run wires to it, I've always liked the idea of a small cmos camera with a LED inside the mailbox.

 

[audioguru]

If you can run wires to it, I've always liked the idea of a small cmos camera with a LED inside the mailbox.

You want to read the mail with it still inside the mailbox?

 

[tunedwolf]

great...but instantly noticed and killed by chewing gum...

 

[philba]

what ever you do, be sure to talk to your mail carrier - they might call the bomb squad and blow up your mailbox otherwise.

 

[DSGarcia]

How about a bright yellow tennis ball and a short piece of string attached to the ball? Tie the other end of the string to a bobby pin or small nail. Use a pop rivet on side lip popped from the inside as well as a corresponding rivet popped from the inside about an inch or so away ( as long as it is less than the length of the pin or nail and allows the door to close). This creates two 'pegs' sticking out the side--one on the door, one on the box. The end of the bobby pin with the string goes over the peg on the box and the other end of the bobby pin goes under the peg on the door. When the door is opened the gap between the pins opens and the ball drops. You may wish to tie an additional (longer) length of string and attach that to the box somewhere to prevent the ball from getting lost when it drops perhaps allowing the ball to hang a foot or so below the box.

We live in the country and have a stone pillar blocking the view of the mailbox, so someday I will do something that requires electrons and RF to work.
Dale