MiOYOOW Line Following Robot Car Kit, Beginners Smart Car Soldering Practice Kit STEM Educational Electronics Soldering Projects for School and Home Learning

Thought I'd try this little smart car kit, I built one long ago, wasn't as nice as this one though. The kit seems small at first, everything is in a little anti-static bag perhaps 3in by 5in (8cm x 13cm?). Spread the components out and it takes up a fair bit of space. Uh, don't do that though... my cat thinks red LED's are fun to bat around. Let's see... 8 resistors, two transistors, two 10K potentiometers, 4 LED's (2 kinds of red), 2 LDR's, 2 electrolytic capacitors, 2 motors, gear sets and wheels, one battery holder (2 AA) and clicky power button. An LM393 dual op-amp, a nice blue PCB, some wire and a handful of screws. Oh, and a bolt with nut and acorn nut to work as a 'caster' wheel. Plenty to do! The kit comes with a sheet of instructions, one side has an oval track on it so you can play with your smart car right away, while the other side has instructions for assembly, a parts list and a good schematic. If you download the 'Smart Car Instruction' PDF file, it expands on the assembly instructions with good quality color photos, allowing you to visually verify you've got things in the right places, right orientation (electrolytic caps, transistors, LED's and op-amp!). Very helpful. Assembly is straightforward, start with the lowest components (the resistors, usually), and solder them to the PCB as directed, paying attention to the silkscreen for LED & eCap polarity and others as needed. I suppose it took me about an hour, I've been soldering for some years (we won't discuss how MANY years!), and it wasn't difficult at all. The possible problem areas might be the 2 pair of LED/LDR's, which are soldered on the BOTTOM of the PCB, where the solder pads are... so you're kinda soldering them in 'backwards', be sure to leave the leads long on those components so you can get your iron in under them. They need to be long anyways to shine on surface and detect reflected light (or not). The gear sets, axles, wheels and motors were fiddly to assemble, you may need three hands to keep the axle and its supports aligned while you tighten the screw on the other side of the PCB. You'll get it... but you may need to try a couple of times to get it all lined up, I did. Get one screw going good, suddenly the other axle support rotates away from its position. GRRRR! Sometimes blue-tak or masking tape can be very helpful! I have a grumble, I feel the battery holder should be installed LAST, as if you're not really careful centering it and keeping it away from other solder holes/pads, you'll have difficulty placing the four wires to power the two motors. The motor power wires must be inserted into small pads which are very close to the side of the battery holder. I'd really recommend leaving the holder until last, as you'll have more room to get your fingers, pliers, tweezers, chopsticks... whatever... in the area to connect the motor wires. Then solder the two leads for the battery holder, wrap the wires around the PCB, double-sided sticky tape the battery pack in place, and voila! Examining my car, I placed the battery holder a bit off-center (only a teensy bit!), crowding the M1/M2 motor wire contacts. just FYI. Now the really fun bit! Turning it on and tweaking the two potentiometers! This is where I'd like to have a blurb in the instructions describing the potentiometer functionality. Yes, you can figure it out by playing with them, the schematic is very helpful as you can determine that they are bias voltage level controls for the dual op-amp trigger levels. And they interact with each other a little bit, so that can frustrate a less experienced kit builder. Basically, they set the threshold for the two LDR's (Light Dependent Resistors). Depending on how much light is reflected back by the surface, the resistance of the LDR changes, changing the voltage presented to the inputs to the dual op-amp (LM393). If the voltages differ, the op-amp output either goes to Vcc or Gnd, depending in which voltage is higher (wikipedia has a good article on op-amps, check it out). If the output is low (Gnd), it turns on its appropriate transistor and energizes a motor. If the output is high (Vcc), it turns OFF the transistor (PNP) and the motor is de-energized, stopping it. You'll have to tinker with the potentiometer settings to get Mr Smart Car to behave, My experience thus far is to start both pots at dead center, and with the power on, tweak them every so very very slightly CCW (counter-clockwise). My car likes to go to the right preferentially, sometimes I can get it to go left... but generally he likes going around the track in a clockwise direction. Your experience will likely vary from mine. You'll swear it has a mind of it's own though. I took mine into work and set up a huge track using electrical tape on a large table. It ran for several hours with people picking it up and looking, then putting it down to zoom around again. We all had fun! I've enjoyed the kit and will likely order more to give to my friends and their kids, perhaps I can spark their interests in electronics. Or maybe a smart car racing club!

I bought this because it looked fun and I thought I could use it to practice my soldering skills as well as play around with a small line-following car without having to program it myself or getting into more complex stuff. This is really just a toy, putting it together takes about one hour or so, and it’s very simple and fun. The instructions are not that bad. That said, I managed to solder everything without needing to read the instructions, because the PCB is well marked up and it’s easy to identify all of the components and where they’re supposed to go. One thing to keep in mind is that the photoresistors need to be relatively close enough of the front “wheel” (about 5mm according to the instructions). Putting together the mechanical part is satisfying, but requires a bit of fiddling to get it right. It is of surprisingly good quality. The PCB is very nice, the layout is well thought and overall the mechanical parts look and feel good as well. Once built, making it work is a little bit tricky. There are two potentiometers, that each control the sensibility/power of the photoresistor and the motor. I didn’t find enough information on the provided instructions to understand how to make it work properly, but it honestly wasn’t complicated at all. Also, make sure to use proper AA 1.5V batteries. Unforunately I only had a pair of AAA in hand as well as a pair of rechargable NiMH batteries. The rechargable batteries didn’t work, I believe because they’re not powerful enough. The AAA batteries worked! However they were loose in the battery holder. Once working, I really enjoyed watching it follow the track on the back side of the instructions.

This is a fun little build that gives beginners a chance to practice soldering while ending up with a working line‑following robot. The board layout is straightforward, the components are easy to place, and everything comes together without much trouble. One thing the directions don’t mention is the need to adjust the small pots to fine‑tune the sensors, which makes a big difference in how smoothly it tracks the line. Once those are dialed in, the car behaves exactly as expected and becomes a satisfying little STEM project.

This little line following robot features a Texas Instruments LM393 comparator as its main MCU, and it does a great job of mating digital electronics with mechanical components in a small package. The parts are fair, but the battery holder is of average quality. It works but the springs and positive terminal contacts seem a bit cheap and I had some difficultly getting AA batteries to fit in the holder, but once they were in they made decent contact and were snug. I didn't need to worry about them popping out, but the contacts had a little bit of an alignment issue. Some of the mechanical parts had unclear instructions, but were intuitive enough that they could be figured out with some guess work. The PCB construction has one feature that I initially thought was a bug: the solder points are only on one side, which makes it somewhat difficult to solder the photoresistors and LEDs. However, this also prevents a builder from soldering them flush to the board, which would make the line reading much more difficult because it would create too much space between the surface of the 'track' and the photoresistors. making the LEDs and photoresistors hang a bit lower improves the ability of this little robot to 'see' the lines more clearly. My particular unit seems to take right turns better than left turns, but I have not yet attempted to tune the potentiometers for cleaner comparisons. It functions rather well and moves quicker than I expected given the gearing. This is a fun little project to help interest kids and enthusiasts in electronics and diy build kits. This seems like it would be a fun kit for a classroom setting because of its inclusion of electronic and mechanical components. The comparator is socketed, so it can be reused in future projects if an enthusiast wants to create something with more utility, and many other parts like the motors, gears, battery holder, and potentiometers could be salvaged for other projects as well. I wouldn't suggest salvaging other soldered parts since many of them have short leads after clipping the excess.

Good for practice, a little expensive.

I bought this Line Following Robot Kit for my 13 year old son and myself to put together. He likes technology and enjoys watching things work, and when I showed him the kit on Amazon he was very excited to receive and build it. While I’ve assembled many kits over the years, I think this was either the fourth or fifth kit he’s put together. The kit arrived on time and in good shape. It was shipped from Amazon in a padded envelope, and is contained within two bags – one clear, one silver colored. I was very impressed to receive an e-mail from the seller through Amazon’s messaging system with a link to a PDF assembly manual. The manual is very thorough – 16 pages long and has lots of nice, clear photos that are annotated with instructions. The kit components are good quality and it comes with a little “test track” that I show in the photos and video. The kit went together well – there are a few places where it took us a bit of time as the parts are small, but nothing we couldn’t handle. The photos in the manual are a big help in putting the kit together. My son soldered most of the components himself without any problems. I did solder the photoresistors and LEDs on the bottom, as the leads were close together and it took a little bit of trial and error to get the photoresistor and LED heights correct. As can be seen in the video, the line following robot works pretty well! We built up a bigger tracking using the electrical tape suggested in the instructions on a piece of cardboard. The electrical tape worked very nicely and we were able to make a much bigger track for the robot to follow. The electrical tape we used was slightly rubbery, so the robot moved slower due to the front support having more friction from the electrical tape than just plain paper. Our pet cats were very intrigued by this little robot running around the cardboard test track. One of them was walking by the edge of the track and the robot kept nudging him along almost like it was herding him! It was pretty funny. We found the robot to be quite durable – while I was trying to set up my phone to take a video, it accidently drove off the track (the track isn’t perfect and had a bad spot) and fell onto the floor, a height of several feet. The batteries did pop out of the battery holder, but there was no damage to the robot. Bottom line, this is a lot of kit for very little money – a really great value, fairly easy to assemble, and works well. Both my son and I were very pleased with it.

I did this as a father-dauther project with my 9 yo over two evenings afterschool. She had never soldered before and this was just enough of a challenge that it kept up a feeling of suspense to see if it would really work at the end or if some component might have been damaged in the soldering process. General comments: It worked in the end. It gave my 9 yo a chance to build something from a circuit board and a bag of lose parts all the way to a working toy car. The one sheet paper instructions was more of a general guide and the track is on the back so don't throw it away. There are QR codes to scan to download the instruction manual and if you search the name of the product you can find youtube videos showing you how to build it. The videos help with confidence but the actual instructions were more accurate in my opinion. I don't think only having digital instructions is a bad thing because it forces you to look at on a screen which then makes it easy to zoom in on the parts and really see what goes where. Overall, I think it's a pretty good kit. You do need 2 AA batteries (not included). Building comments: Make sure you have the right tools to start. You will need 1) a soldering iron (off Amazon or locally from a hardware store / big box retailer), 2) solder (normally comes with a soldering iron), 3) wire cutters, and 4) a small Philip's head screwdriver. Sort out all of the pieces and pay close attention to the colors on the resisters (small tubes with a wire going out of each end). Match up the colors as exact as possible with the photos and you will be fine. The lights have one positive and one negative wire coming out of it. The positive wire is slightly longer than the negative. If you look on the circuit board there will be one round (negative) and one positive (square) pads. The longer wire goes to the square pad and the shorter one goes to the round pad. The gears on the motors should not be pushed down all the way. Just push them on enough so they stay and turn, this will give you more leeway with positioning the gears for the wheels to connect. I would hold off installing the battery wires and tray until the very end. If it does not work correctly at first, check that there is enough solder to make a good connection for all of the parts. Check that the lights and sensors are allighted together so it can see the light bounce back.

This kit works as advertised. I would not recommend it for young children as some of the soldering is a bit tricky. I'm an adult with an intermediate skill level and this kit took me about two hours to complete. Downloading the online instructions is a must as the paper instructions are not very helpful. Even then, expect to spend some time puzzling out some of it. It would help a lot if some of the instructions were reordered, for example it would be a lot easier to solder the motor leads to the board before attaching the battery holder. As you can see from the video, the car does work just fine. You have to do a bit of fine tuning with the adjustable potentiometers before it tracks the line accurately, and it did get confused one time in my video. There are no guidelines on the instructions about doing this adjustment but it's fairly intuitive. This is a completely analog implementation of line following using leds, photoresistors, and an op-amp. I'd like to see a more sophisticated version that did some more digital processing. It would also be nice if the front guide was a wheel instead of a metal cap. Overall, this is a perfectly fine kit at a reasonable price. If you want to improve your soldering skills and do some electronics assembly, go ahead and buy it.