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  • Author Author: jw0752
  • Date Created: Date Created
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Walking in the Dark

jw0752

One of the things that I like to do each day is go for a nice long walk. What makes me a little unusual is that I like to do it at night when it is quiet and dark. I typically leave the house about 11 PM and walk for about an hour and a half. My routes vary from night to night but I am most often on sidewalks or on the roadway when there are no sidewalks. Last night as I walked through a particularly dark section of town I caught my boot toe on a piece of raised sidewalk that was not visible in the dark and nearly took a fall. Only a valiant effort that resulted in a couple sore muscles saved me. I always have a flashlight with me but I almost never use it for walking and only bring it out to call attention to my presence when cars approach and I am in the roadway.

 

Today as I reflected on my near fall I decided to design something to make my walks a little safer. To this end I give you "THE BOOT HEADLIGHT"

 

   imageimage

 

The boot headlight is more than just a flashlight attached to my boot. It also has a photo-resistor and a comparator so that it is only on when I am in dark areas where the holes and cracks of the sidewalk are not visible. As soon as I step in the light of a street light or as I walk through the downtown area the boot light stays off. The low angle of the light mounted on the boot makes raised parts of the sidewalk show in high contrast. The raised edges that face me as I walk show a bright lines across the path and the edges that face way from me show as shadows. On my test walk tonight, the Boot Headlight worked well and made it easy to avoid dangerous obstacles.

 

Here is the simple schematic for the boot headlight and a closeup of the circuit board and battery strapped to the boot with a velcro band.

 

   imageimage

 

The quiescent power drain is 2 mA which rises to 4 mA when the LEDs are lit. I will be taking note of how long I can use it before the battery has to be replaced. While I have put the unit on my boot it could also be strapped to a leg or a belt, though I really like the low angle effect of the light on the sidewalk hazards when it is on the boot..

  • in reply to colporteur

    Wow, reverse polish notation. It must be getting on for 35 years since I have heard this phrase. It never made any sense to me until I did some work with LISP ( I think it was ). It didn't make much sense afterwards either. A bit like

     

    a = a + 1;

     

    in C really. It just cannot be true in the literal sense of the meaning of the symbol =. I took to thinking of = as meaning 'takes on the value of' after learning VHDL. It made more sense then. Then I got older and couldn't be bother being a pedant.

     

    Dubbie

  • in reply to jw0752

    John,

     

    I will have to admit that my nocturnal hikes are more a thing of the past.  Since moving to Texas, with the heat and humidity, the last thing that I want to do is go walking at night.  The weather and the bugs and other crawly things that we have here, make the night a far less comfortable environment for walking.  Funny, having said that, I still like to get out and be in nature (even with the heat), but being able to see clearly in all directions feels safer.

     

    Gene

  • Can I borrow the calculator sitting on the desk behind the boot?

     

    The batteries in my reverse polish notation HP calculator are dead:)

     

    Nice simple, elegant project.

     

    Sean

  • in reply to genebren

    Hi Gene,

     

    It seems that what I thought was unusual behavior is fairly common at least among the electronically inclined. I am glad that I am not the only one who enjoys a nocturnal hike.

     

    John

  • John,

     

    Another cleaver device.  Walking at night can be treacherous, so I can see how this would help.

     

    I used to teach electronics in a private (for profit) school that had classes from 7:00 pm until 10:00 pm.  I would get home so wound up that I would take to streets and walk through the neighborhood in an attempt to unwind.  It helped a lot, but I did need to get the distance up enough to help.  By the time I was done and relaxed, it was between 12:00 and 1:00.

     

    Gene