Reddit reviews DAOKI 5PCS TCRT5000 Infrared Reflective Sensor Module IR Barrier Line Track Photoelectric Switch
We found 2 Reddit comments about DAOKI 5PCS TCRT5000 Infrared Reflective Sensor Module IR Barrier Line Track Photoelectric Switch. Here are the top ones, ranked by their Reddit score.
Using infrared reflective sensor TCRT5000.Detection of reflection distance: 1 mm to 25 mm.The comparator output signal clean, good waveform, driving ability, more than 15mA.With a multi-turn precision potentiometer adjustable sensitivity adjustment.The working voltage of 3.3V - 5V.
Optical sensors that I bought off of amazon:
https://www.amazon.com/gp/product/B00XT0PBC0/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
They work flawlessly. Their max sensing distance is probably a little more than 1/2", so the balls have to pass fairly close to them. I ordered some blaze orange balls and they work perfectly with those. Then I ordered a set of lime-green balls and for whatever reason, those balls do not trip them AT ALL. I haven't yet found anything else that doesn't trip them.
H-Bridge (for the UNO there are also shields)
Sensors e.g. this / that though you can also get tctr5000 modules for cents elsewhere.
And note that if you are not set on a line-follower, the kit you've chosen already includes the ultrasonic distance sensor which is nie for robotic projects as well :-)
Do you have a soldering iron and multimeter? Even a cheap $4 multimeter is fine for low-current & low-voltage tasks, and makes your life easier (checking voltages, connections, resistor values...)
As for a soldering iron, even a $1 will do (if it doesn't burn down your house ;-) ) - but an adjustable temperature one will be more worthwhile. Even a $20 soldering station will do to get started if you don't want to spend $80-$100. I tried to avoid soldering for years, and it was a big mistake. It's actually easy and useful.
And another note: The 2wd and 4wd chars will not always go in a straight line. Motors don't run 100% in sync, even at the same voltage.
With a rotary encoder you can ajust the speed in software. You can use one of those IR reflective sensors modules, or a gap sensor, or even a hall sensor... example
You can also get 2wd kits example, but overall, they aren't as great of a value (and as you can see, they just include the standard modules)
A "sensor shield" like in that kit is nice though as it reduces the wiring chaos a bit :-) They cost $1 for the UNO at Aliexpress, probably more expensive at Amazon.