First project idea...

JimmyDigital

Hello all...

I have some experience with building electronics... a bunch with computers/linux etc... some with programming in shell script and php... but none with micro controllers and I'm wondering how realistic an idea for a project is. I'm also a pilot.. and my little airport does not have PLC or Pilot Controlled Lighting.. basically when it's dark you can key the mike 7 times and turn on the runway lights. Some systems are more sophisticated and allow you to set various dimming levels.. but all I need is a simple on/off. They should stay turned on for a preset time.. say 15 min.. and have a photo sensor to only work when it's dark.. and a manual override for turning them on with local button. An led countdown display would also be nice.. but not required. To minimize cost.. my thought is to place a small microphone near the loudspeaker of the base radio... and pick up the clicks from there.. rather than getting a dedicated scanner and using the line out from it.

For those who know what it takes to get up to speed with the stamps... is this a workable first project? Of course I'll take any help that you want to provide. =]

A next project... somewhat related.. is to make a better airport beacon... possibly using xenon flash lamps.


Thanks,
Jared

Jon Williams

The project is in fact very realistic because I did it 11 years ago for another pilot using the simplest of our products: the BS1.· I've attached the [noparse][[/noparse]updated] code.· You could load that into our Prop-1 controller (an industrialized BS1) and be able to connect directly to relays that control the lights (with appropriate code changes).

As I recal (from a long time ago) the interface to the BASIC Stamp was an 555 timer that created a clean (and streteched) pulse from the audio line, hence the one-shot reset signal that would reset the 555 after the pulse was detected.

Good luck, I hope this helps.

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Jon Williams
Applications Engineer, Parallax

JimmyDigital

That's great... thanks!

Looking at your code.. I can see I have a lot to learn if I want to start developing for these boards. I'll get my hands on some hardware before I start asking dumb questions. =]


J

JimmyDigital

So I have picked up a prop1 board for this project... and I'm finding that to be the easy part. =] Since I have no formal electronics training.. I'm not really equipped for this... I've been trying to get as much info as I can about 555 timer circuits and how to use them.. but I have yet to find anything that is directly on point... triggering from a microphone input. I know I want a monostable setup.. and I know I'll need to amplify and filter the mic input.. but I'm not having much luck figuring out the details. I've also been reading about how to do simple A/D conversion with the stamp for interfacing with the photosensor... but I have yet to look at that bit. I would appreciate any help you could give on this... I know it's only a matter of a handful of components... but I'm just not sure where to start. On my bench I have two DMMs.. logic probe.. and an older 40mhz scope. My experience has been mostly in building kits.. troubleshooting and finding bad components... but not in designing new circuits.

Thanks,
J

Robert Kubichek

JimmyDigital said...
Hello all...

I have some experience with building electronics... a bunch with computers/linux etc... some with programming in shell script and php... but none with micro controllers and I'm wondering how realistic an idea for a project is. I'm also a pilot.. and my little airport does not have PLC or Pilot Controlled Lighting.. basically when it's dark you can key the mike 7 times and turn on the runway lights. Some systems are more sophisticated and allow you to set various dimming levels.. but all I need is a simple on/off. They should stay turned on for a preset time.. say 15 min.. and have a photo sensor to only work when it's dark.. and a manual override for turning them on with local button. An led countdown display would also be nice.. but not required. To minimize cost.. my thought is to place a small microphone near the loudspeaker of the base radio... and pick up the clicks from there.. rather than getting a dedicated scanner and using the line out from it.

For those who know what it takes to get up to speed with the stamps... is this a workable first project? Of course I'll take any help that you want to provide. =]

A next project... somewhat related.. is to make a better airport beacon... possibly using xenon flash lamps.


Thanks,
Jared

Hmm, sounds like an excellent application for a vox circuit, or added to that a dtmf decoder, both are used on repeaters for Ham radio.
The VOX has a keyed output that CAN send an ON/OFF signal to the BS1 that would count the pulses and switch on the beacons, likewise with a DTMF
decoder.
You can even use a pl tone to turn on beacons that turn off after a set time.
There are many vox kits that are very inexpensive..

Here are some;

www.rainbowkits.com/kits/vox-1p.html
www.elexp.com/kit_vox1.htm
store.qkits.com/moreinfo.cfm/QK126


The ways to trigger them on is many....

Bob N9LVU

JimmyDigital

Thanks for the tip... I got the vox kit from the Qkits site.. and with a couple changes (C2 as .1 and 4.3k R3) I was able to get it to work just as I need it to. I did see one little problem with the example program.. and that is if the lights are already on.. and someone activates them again... like to keep them from goinig off.. it wouldn't pick that up since it was locked into the countdown. I haven't built the darkness circuit yet.. but here is the code as I've changed it to fix this problem. Comments? This of course is my first attempt at writing code for this chip..

http://store.qkits.com/moreinfo.cfm/QK126
http://www.uoguelph.ca/~antoon/circ/sensor4.htm