Posted by a reviewer on Amazon

Works better on an oopic than arduino

Posted by a reviewer on Amazon

As other reviewers i had to solder a 33k resistor it makes a huge difference

Posted by a reviewer on Amazon

Youll find this kit under product names here on amazon likemakerfire® arduino 2wd motor robot car chassis kit with wheel encoder photoelectric sensorsodialr wst motor smart robot car chassis kit speed encoder battery boxemgreat® motor robot car chassis kit with speed encoder wheels and battery boxsmart robot car chassis kit speed encoder battery box for arduinoall of these kits have a cutout in the chassis to receive this module but the module is not included in any of these kits

Posted by a reviewer on Amazon

Here is the detail of what needs to be fixedthe module is a standard ir emitterdetector pair that shines ir light through the slots in the encoder wheel

Posted by a reviewer on Amazon

As the wheel turns the detector sees light pulses which are turned into electrical pulses via a simple comparator circuit

Posted by a reviewer on Amazon

Note that these are not quadrature encoders so the tach pulses show speed but not direction

Posted by a reviewer on Amazon

The circuit problem is that the comparator circuit was designed without hysteresis so the output oscillates at the transitions between light and dark

Posted by a reviewer on Amazon

I was planning to use the output tach signal as an interrupt for my arduino project and these oscillations were all being counted as separate tach pulses