A control box is placed at the start and finish of the course and each each fox position. The competitor carries a iButton device contained in a key-fob. When the iButton makes momentary contact with a socket on the control box the real time is recorded on the iButton. The contents of the iButton are downloaded to a PC after the event and this enables the computer data to be used to to generate results lists, comparison run times and a multitude of other posibilities depending on the software.
I have tried to maintain the concept of ‘keep-it-simple’, but made variations to the original the design to provide a preferred solution for a given cost, availablity of component and hardware. Here is a quick run down of design choices.
I have used a standard Hammond translucent box. Not the cheapest option, but to be honest, it was originally selected because it resembles the commercially available ‘Sportident’ (SI) control box, and was therefore more likely to be ‘acceptable’ to regular uses of the SI system !
However the box can be bought in bulk for a very reasonable price from Rapid Electonics. Like most ‘project boxes’ it has a screwed top – so the design incorporated a concealed latch switch behind a rubber ‘button’ to turn the unit on and off. Also, a countersunk screw is connected to the positive battery terminal so the battery voltage can to measured without having to remove the box lid.
footnote – the ABS material seems to be vulnerable to stress cracking around drilled holes. An identical sized box in polycarbonate material might be a better choice, but this has yet to be tried and tested.
I must give credit here to my wife, Elaine, for coming up with the idea, which resulted in using a standard keyring for the basis of the socket design. A 16mm keyring is a perfect fit for the iButton. The keyring needs to be expanded so its height is slightly above a centre contact pin. The photo shows the arrangement with the keyring soldered to a small piece of 25mm x 25mm pcb. The open frame of the socket means water is far less likely to be trapped inside the socket. Most important is the painting of the pcb and the lower portion of the keyring to minimize the possibility of rain water bridging the socket terminals.
footnote – the photo shows a round headed bolt, but this can put a dent in the face of the iButton with frequent use. Probably users are applying unnecessary excessive force when punching. I suggest changing the bolt for a flat head type.
PP3 were deemed far too expensive for this application ! An AA cell is used with a step-up regulator type NCP1400 and the cost of the regulator will be recouped with the first battery change.
The output rating of the NCP1400 is greatly reduced when using a single AA cell for 5v output, so as the NCP1402 is now readily available in the UK, that should be used in new designs.
Below are links to my software code, originated by 9A5SP and modified by G3ZOI.
Please observe the request by 9A5SP to publish all improvements in accordance with the Artistic License 2.0
Please be aware this software is ‘work-in-progress’, but it has been used successfully on a number of RSBG ARDF events.
PIC Software for the fox location control box.
This is written in Mikroelektronika BASIC (free to use , with a very generous 2k program size limitation.)
In the ‘project settings’ :- use device = P16F628, Frequency = 4.194304 MHz
PIC software here.
MS Windows Software for the downloading from iButton.
This is written in Delphi. All library files are included. If you keep them together in one project folder. Delphi should run and compile the code without further configuration.
Dephi 6 & 7 should run under Windows Vista and above – just ignore the error dialogue messages when first loaded.
The current software version requires the ini file and the exe file to be in the same folder, then the output files are created in the same (event) folder.
The main source file is raydelun.pas.
The output files are
- [eventname].log – this is a compilation of individual competitor results, as they would appear on a printed results ticket.
- [eventname].kor – this is a ‘correction file’ which can be read by the FjwW program for results analysis and web publishing. (see below for examples)
The .pas file also has code (commented out) to output in OR format, but I regret I can’t remember how well that works !!!
MS Windows software here.
Examples of results using iButton, and then published using FjwW here.
happy punching !