...of a model train.
Hi folks,
Does anyone have any practical experience of locating trains automatically on a model railway? The purpose would be automating the running of the railway, such as the routing of trains, signalling, etc. The first requirement is that the hardware needs to be kept out of sight under the baseboard. This rules out e.g. the train breaking a beam as a potential solution. Secondly, some dozens of these position sensors will be needed, so the hardware will need to be simple and cheap.
A couple of ideas so far. Firstly, an IR LED and its matched photodiode. A series of pairs of holes are drilled through the baseboard such that each pair is side by side under the track. An LED goes in one of the holes and the sensor in the other. These are mounted on a PCB (for mechanical support and electrical interface) which is screwed into place on the underside of the baseboard. My thinking is that a train (with some reflective painting on its underside?) running over the top of this can be detected. However, preliminary testing (without any baseboard) suggests that ambient light may be a problem, which would mean analogue detection of the presence of a train would be needed. The interface chip is a 28X2, and this must support up to 9 of these sensors, and running 9 ADCs at the same time as well as signalling and communicating with the outside world sounds like too much, assuming it's even possible in the first place. I'd much rather have digital outputs from the sensors.
This led to the second idea of gluing a small magnet to the underside of the locomotive and using a Hall effect sensor under the tracks. This is new territory for me though, and I'd welcome any feedback from those with any experience.
Hi folks,
Does anyone have any practical experience of locating trains automatically on a model railway? The purpose would be automating the running of the railway, such as the routing of trains, signalling, etc. The first requirement is that the hardware needs to be kept out of sight under the baseboard. This rules out e.g. the train breaking a beam as a potential solution. Secondly, some dozens of these position sensors will be needed, so the hardware will need to be simple and cheap.
A couple of ideas so far. Firstly, an IR LED and its matched photodiode. A series of pairs of holes are drilled through the baseboard such that each pair is side by side under the track. An LED goes in one of the holes and the sensor in the other. These are mounted on a PCB (for mechanical support and electrical interface) which is screwed into place on the underside of the baseboard. My thinking is that a train (with some reflective painting on its underside?) running over the top of this can be detected. However, preliminary testing (without any baseboard) suggests that ambient light may be a problem, which would mean analogue detection of the presence of a train would be needed. The interface chip is a 28X2, and this must support up to 9 of these sensors, and running 9 ADCs at the same time as well as signalling and communicating with the outside world sounds like too much, assuming it's even possible in the first place. I'd much rather have digital outputs from the sensors.
This led to the second idea of gluing a small magnet to the underside of the locomotive and using a Hall effect sensor under the tracks. This is new territory for me though, and I'd welcome any feedback from those with any experience.