from Hacker News

Arduino-Based Outdoor People Counter

by matell on 5/11/14, 7:34 PM with 9 comments

  • by danpat on 5/11/14, 8:56 PM

    Nice project, and will probably work great for short-term studies, but you'll want to improve the battery life and work hard on weatherproofing if it's to be used in the field for anything other than temporary projects.

    I used to work for a company (http://www.trafx.net/) that specialized in making a device just like this, but using a passive infrared sensor instead of the ultrasonic sensor. The number one field problem is moisture damage to the electronics. Condensation, UV failure of seals, ice expansion through seals, etc. The list goes on. Based on the moss on the trees in the photo, it looks like a pretty wet environment, so you'll want to double-triple-quadruple seal that case and sensors before you think about leaving it outside for more than a month or two.

    For comparison, we had some customers that had had our units in continuous use for nearly 10 years. Battery life on 3xAA alkaline was about 60 months using the IR sensor. The Arduino+ultrasonic sensor is a pretty power hungry combination for a battery-operated unit that might need to operate for extended periods. 5 days is a pretty short study period, a lot of the useful statistics that land management organizations want to see will span multiple years.

  • by alexisnorman on 5/11/14, 10:49 PM

    This may be a dumb question, but isn't this more of a "movement detection counter" rather than a "people counter"? Nothing sets apart an animal vs a human triggering this, right? I was imagining a camera with CV processing the images or something.

  • by vog on 5/11/14, 9:45 PM

    From the description:

    > Video [here]. Photos are [here].

    Sorry for the nitpicking, but I think you should avoid "here" links and use descriptive link names instead. (http://www.w3.org/QA/Tips/noClickHere)