The Linn County Trail Association is looking for help to develop concepts and to implement working hardware to automatically count trail users on our local trails. This task presents some interesting challenges. The trails are used by walkers, runners, skaters, and cyclists. They move at various speeds in both directions in single file and in parallel. While a simple counter has value, a more complete solution would account for people pushing strollers and bikes that are tandems, recumbents, with child seats, or attached tag-along. The count needs to have credibility. Some degree of concealment or vandal proofing would also be helpful. Requested by Linn County Trails Association, Myron Wilson, President.
This project has had three major updates over the years from 2003 to 2012. The updates are identified by serial number sequence: S/N 1-10, S/N 11-12, S/N 20-29.
The IR transmitter is placed on a post on one side of the trail and the receiver is on a post on the other side of the trail no more than 20 feet apart. The IR beam is approximately 3 feet above the trail surface. The electronics are placed on top of the posts and a hood slides over the electronics. Windows are cut in the hoods for the IR beams and a window at the top for the odometer readout. Lexan windows are glued into the holes in the hood. A bar and padlock are used to secure the unit. The transmitter batteries are quite large and are stored inside the post below the electronics. The posts and hoods are made of steel or aluminum. A PVC post and hood was tried and is much more economical, however it is easily broken into. One PVC post set is still in operation.
Counter Series 1-10
Trail counters have been designed and built using an infra red (IR) beam to detect passage. Ten counters have been built using a modified TV remote as the transmitter and a surplus electronics board as the receiver. The receiver electronics drives a mechanical odometer readout. The surplus electronics board was modified to meet the timing needs of the trail counter. The transmitter operates with two D cell batteries. The batteries last between 45 and 60 days. The receiver electronics operates with 9 volts provided by 6 D cell batteries. However the mechanical odometer requires approximately 23 volts and so an additional 14 volt battery is used to drive the odometer. The 14 volt batteries are obtained from Emergency Locator Transmitter (ELT) units installed in private airplanes. The batteries must be periodically replaced in the airplane; however they still have a useful life. The transmitter has a low battery drain and most of the transmitter batteries last more than a year. The receiver board has surface mount components which are very hard to maintain but result in very low battery drain.
The 14 volt ELT batteries are no longer available. The units are being converted to a 6 volt odometer so the units may be operated with 6 and 9 volts instead of 9 and 24 volts.
Designed and built by Dick Kittrell in 2003. The first counters were installed in 2004.
Counter Series 11-12
The original IR transmitters and receivers were made by modifying surplus electronics boards. The boards were no longer available. The design was modified to use commercially available integrated circuits and to operate at lower voltage. The 24 volt odometer was replaced with a low cost 6 volt odometer.
Modified and built by John Wauer in 2009.
Counter Series 20-29
The counters were redesigned and laid out for efficient construction by Dick Kittrell and built by Kay Nelson. These units use a single 6 volt battery supply. Lantern batteries were originally planned but the quality of lantern batteries was so poor that we changed to D cell batteries in a plastic holder. The update was completed in 2012.
RCRV designer is Dick kittrell, and was requested by Linn County Trail Association. The project was begun Jan 8, 2003 and completed Jul 1, 2012.
These pages may require the free Adobe® Acrobat® Reader® to display.
Circuits, S/N 1-10
Circuits, S/N 11-12
Circuits, S/N 20-29
Construction drawings for the trail counter posts