Hello all. I have a personal need for a small circuit. I have a good understanding of components, how they are connected, and actually building them, but an electrical engineer I am not. I was wondering if someone could lend me a hand. It's probably very simple in design. Attached are my requirements:
- Needs to be as small and light as possible.
- Attachable with Velcro. I'm imagining a PCB where the back has a stick on Velcro pad.
- Small momentary button that when pressed, activates a 15 second timer (approximately and no display needed). When the 15 seconds expires, a small speaker should emit an audible chirping sound (audible from within approximately 50-100 feet outdoors in a relatively quiet setting) at 5 second intervals. This chirping will continue until the button is pressed again.
- There may be two buttons if size/weight/complexity is smaller/lighter/simpler than required circuitry with single button.
- Replaceable battery (I'm imagining a watch size battery).
- Should be able to take a bit of bumping around. It is for a child's use and will be attached to something that will undoubtedly be thrown or dropped.
- Did I mention as light as possible??? :-)
I've bought from Allied et all in the past, so buying the speaker, buttons, battery holder, etc. shouldn't be a problem. The physical layout and PCB building should be something I can do. This is just a little project for my son and me so I can just etch a board (hopefully one layer is enough). I just have no idea what components to use.
Thanks very much for any assistance!