I'd like to make a 'mail alert ' rf system ( for snailmail). My mailbox is 250+ ft from the house, and on cold days I don't like to venture up there until I have to. On the other hand, I prefer to do it during (the few) daylight hours we have in the winter.
Has become more of a problem lately. Mail used to get here between 3:30 and 4. So, it worked out OK. Now it sometimes doesn't show up until almost 6, and of course there are the days when we're not blessed with catalogs and bills.
In any event, I just want some kind of small transmitter that will transmit a one time short burst when the mailbox door is opened. Several issues come to mind
1. The door 'switch' needs to be a little tolerant, in case the door doesn't get fully closed -- mercury switches come to mind, but they are probably frowned upon these days.
2. I have no idea what would be a reliable ( and cheap) rf system. I will gladly do the investigation, but I'd like some direction.
- I've worked with RF, but I'm hoping for 'modules' or at least a cookbook design.
3. Low power -- I'm thinking lithium batteries due to the temperature range. Ideally, it should just power up when the door is opened and auto shut off after. I have some ideas about that, but any thoughts are appreciated.
ps -- we're probably 500 feet from the nearest neighbor, so rf conflicts are probably not an issue.