Trying to get a reliable lap counter for slot cars. Currently have a gantry with infa red sensors, but too unreliable. I have a manual lap counter that works great but want to have a digital display. Is there an Arduino product that could be linked to the underside of the lap counter, not a sensor but a mechanical system? Cheers.
PersonallY would concentrate on making the infra red sensor solution reliable
I presume that the cars cut the beam between an LED and the sensor. Which sensor are you using ?
In the following article, the "IR Infrared Slotted Optical Optocoupler Module Speed ​​Measuring Sensor" is used.
Photo attached. I haven’t split the led and receiver. I’d have to split them and put one under track. Different coloured cars and different lighting conditions play havoc. I wondered if there was an Arduino item that the arm on the manual lap counter activates a signal.
Forgot to mention cars are ho scale so a bit more of a challenge with ir sensors. May even try a laser setup.
Thank you. Any idea what they are called so I can do a search.
I see no 'photo
If you are relying on the cars reflecting the infra red beam rather than cutting the beam then no wonder it is unreliable
Micro limit switch.
There are many different sizes and actuating lever types.
Thank you.
It would probably be better to have the sensor on the gantry to avoid any effects of room lighting above the track
@grahamgreen
Have a look at this topic, it used 1/32 scale cars.
Not as easy as you think
Yes, absolutely. Detecting when light is reflected by a car versus the track isn't going to be reliable.
Detecting when light is blocked by the car should be far more reliable.
By the way, those boards in your photo are a waste of space and money. All you really need is the IR LED and IR phototransistor from the board, plus a series resistor for the LED. Connect the LED & series resistor between 5V and ground. Connect the phototransistor between an Arduino pin and ground and set the pin mode to INPUT_PULLUP.
I would recommend mounting the IR LEDs above the track (you may only need one) and the two IR phototransistors under the track so that they are under the shadows of the cars as they pass. If you mount the phototransistors above and have the LEDs under the track, there's more chance a phototransistor will still be illuminated by the other car's LED when it's own LED is blocked by a car.
A small slot sensor might work to detect the passing of the pins.
Your idea is not unlike something we would see in the gate control and garage door industry (edited…not that particular hardware of course, but the same concept).
Often the concept is used as a break beam safety feature. And often in access control (not so much garage doors) the beam is reflected back to the receiver via a standard type of reflector like a white bicycle reflector. Nothing fancy. These photo reflective systems are very reliable if properly installed.
I don’t know how much clearance the slot car has above the track, but is there enough clearance to add a piece of reflective tape on the track under the gantry? The beam would shine down and reflect back up. When the car passes over the tape it breaks the beam, triggering a count.
