Hello all. Help please!!
I could really use any suggestions about this project. I've never built an electronic project, but understand basic electricity, can solder, have wired some of my house and home intranet, have moderate mechanical skills, and have 20+ years professional programming experience in various BASICs and in research.
The dog now needs out hourly instead of just before and after work. This is causing great stress, so we're looking for a fast solution (that's not too expensive). Commercial units to let the dog open our sliding glass door range from $400 for one that won't fit our situation to $1600 that will do the job, but all need weeks to deliver. (Non-electric units aren't readily available or won't keep the riff-raff, i.e. cat, out.)
Here's my idea ...
- Use a junkyard auto window lift to open and close slider; I seem to remember a unit that uses a ladder-shaped plastic chain or belt that I thought I could easily tie 1/16 inch cables to either end of.
- Motor would open door, pause 2-5 seconds, and close.
- Mount motor at opposite side from slider opening; cable end 1 goes to near bottom corner of slider to pull it open; cable end 2 goes up and around through 2 pulleys to top far side of door to pull it closed.
- Train dog to push foot switch on inside or outside to trigger open/close event (this is an extension of her sign language for going out); later, to help keep out the riff-raff, add capability for proximity switch ... while protecting against pooch holding the door open by sitting at door watching the squirrels.
- Put springs in cables to protect dog if she sits with tail in door; later, add safety mechanism similar to elevator door.
- Microswitches to detect when completely closed and completely open.
- Use Dept of Ed carrier and one of the Basic Stamps (which one?) that I might be able to find locally (Radio Shack), to reduce lead time, learning curve, and development time.
I'd like to begin building in a couple of days. It seems like I could do this for under $200, maybe even under $150.
Any help would be greatly appreciated. Am I even taking a reasonable approach? Thanks!