Following another impact from an vehicle on my thatched roof I am planning counter measures.
As part of these counter measures I need to detect oversize vehicles approaching the junction involved.
A through beam sensor would be ideal. I have permission to fit a module on the house on the other side of the road but to get power to it would be a problem. A battery powered TX is a possibility but will require frequent battery changing.
A passive reflector on that house would work BUT some high vehicles will reflect enough IR to make the beam receiver believe it can still see the reflector on the house. So those vehicles will pass un-detected.
The distance measuring devices similar to those used by surveyors and estate agents would be ideal if there was way to read the distance into a micro-processor. If it reads 11.9 metres it is the house with no vehicle in the beam. If less than 8 metres then it is a vehicle.
Other than a £ 700 device with an analogue output of the measured distance I haven't been able to find one suitable.
As part of these counter measures I need to detect oversize vehicles approaching the junction involved.
A through beam sensor would be ideal. I have permission to fit a module on the house on the other side of the road but to get power to it would be a problem. A battery powered TX is a possibility but will require frequent battery changing.
A passive reflector on that house would work BUT some high vehicles will reflect enough IR to make the beam receiver believe it can still see the reflector on the house. So those vehicles will pass un-detected.
The distance measuring devices similar to those used by surveyors and estate agents would be ideal if there was way to read the distance into a micro-processor. If it reads 11.9 metres it is the house with no vehicle in the beam. If less than 8 metres then it is a vehicle.
Other than a £ 700 device with an analogue output of the measured distance I haven't been able to find one suitable.