Hello! I'm starting a new project and I would like to here your thoughts about the solution I developed (in my mind) before going further. The requirement is to sense a vehicle passing through a street up to 5m wide (16 feet).
After reading about IR transmission I came up with the following solution:
I'm going to build two modules (transmitter and receiver).
The transmitter is going to send a continuous pulse train of 1kHz 50% duty cycle, of a carrier frequency of 38kHz (just like remote control systems do). It will use an IR led.
The receiver is going to get the IR signal using a phototransistor. There will be an LM567 calculated for the 1kHz signal detection using the typical application circuit.
Let aside power supply and optional amplifying stages that may be needed. My main concern is building a simple solution, suitable to work outdoor (with rain and sun) and with other IR light sources which could add noise to my detector. Besides, I'm going to place two different detectors near each other. There is a good chance one detector receives light from both transmitters. My idea is using different pulse train frequency such as 1kHz and 3kHz (having into account limits imposed by carrier frequency and LM567 bandwidth).
After reading about IR transmission I came up with the following solution:
I'm going to build two modules (transmitter and receiver).
The transmitter is going to send a continuous pulse train of 1kHz 50% duty cycle, of a carrier frequency of 38kHz (just like remote control systems do). It will use an IR led.
The receiver is going to get the IR signal using a phototransistor. There will be an LM567 calculated for the 1kHz signal detection using the typical application circuit.
Let aside power supply and optional amplifying stages that may be needed. My main concern is building a simple solution, suitable to work outdoor (with rain and sun) and with other IR light sources which could add noise to my detector. Besides, I'm going to place two different detectors near each other. There is a good chance one detector receives light from both transmitters. My idea is using different pulse train frequency such as 1kHz and 3kHz (having into account limits imposed by carrier frequency and LM567 bandwidth).