Overview of the system
Detailed description of the system components
The system is made up by the following components:
I believe this system will be very reliable. The tests so far have given good results. I have run 3000 rounds on an oval track with three sensors and one decoder, without any errors or missed readings. In previous tests I have run another 3000 rounds with one sensor and a simpler test version of the decoder, also without any errors. In total this sums up to 24000 readings and several hours of operation. In later tests I have noticed that the sensors can shake out of position and cause missed readings, but this can be prevented by securing them with a piece of tape.
Simulation shows that the system has a capacity of over 100 readings per second without any missed readings.
What could be a problem is that the sensors react on normal light. They do have daylight filters, but this is not 100% effective and the sensors may be blocked if there is too much light on them. I have observed this while developing the system, but I have not so far seen any problems when the sensors are installed in the track.
The final version transmitter circuit boards have been manufactured. The boards have been tested and I have mounted them in most of my locos.
I have manufactured circuit boards for the sensor, for Märklin M tracks. I have assembled and tested around 50 sensors. This is enough to control my layout, but maybe I will add some more sensors later.
I have assembled six decoders so far. I build the decoders on Veroboard instead of making a real circuit board layout. The decoders have been verified through both real tests and simulations. I made some successful tests with all 6 decoders and 48 sensors when I had my layout set up in April-May 2004.
I have also built the interface, and written a simple monitor program on the PC to check that the whole system works. I have not yet had time to write any real control program for my layout.
Since most components are much cheaper in larger quantities, I will have more pieces than I need. So if you want to experiment with this yourself, I might be able to supply you with some of the components.