Who would not like to have a universal assistant, ready to carry out any task: wash dishes, buy food, change a tire in a car, and even take the children to the garden, and the parents to work? The idea of creating mechanized assistants has occupied engineering minds since ancient times. And Karel Capek even came up with a word for a mechanical servant - a robot that performs duties instead of a person.
Fortunately, in the current digital age, such assistants are sure to become a reality soon. In fact, intelligent mechanisms already help a person in doing household chores: a robot vacuum cleaner will clean up while the owners are at work, a slow cooker will help cook food, no worse than a self-collecting tablecloth, and a playful Aibo puppy will happily bring slippers or a ball. Complex robots are used in manufacturing, medicine and space. They allow you to partially, or even completely, replace human labor in complex or hazardous conditions. Androids are trying to look like people, while industrial robots are usually created for economic and technological reasons and their external decor is by no means a priority.
But it turns out that you can try to make a robot using improvised means. So, you can design an original mechanism from a telephone receiver, a computer mouse, a toothbrush, an old camera or the ubiquitous plastic bottle. By placing several sensors on the platform, such a robot can be programmed to perform simple operations: adjusting the light, giving signals, moving around the room. Of course, this is far from a multifunctional assistant from science fiction films, but such an activity develops ingenuity and creative engineering thinking, and unconditionally arouses admiration among those who consider robotics to be absolutely not artisanal.
Cyborg out of the box
One of the most simple solutions on the way to making a robot - purchase a ready-made robotics kit with step by step guide. This option is also suitable for those who are going to seriously engage in technical creativity, because in one package there are all necessary details for mechanics: from electronic boards and specialized sensors, to a stock of bolts and stickers. Along with instructions that allow you to create a rather complex mechanism. Thanks to the many accessories, such a robot can serve as an excellent base for creativity.
Main school knowledge in physics and skills from labor lessons is enough to assemble the first robot. A variety of sensors and motors obey control panels, and special programming environments allow you to create real cyborgs that can execute commands.
For example, the sensor of a mechanical robot can detect the presence or absence of a surface in front of the device, and the program code can indicate in which direction the wheelbase should be turned. This robot will never fall off the table! By the way, real robotic vacuum cleaners work on a similar principle. In addition to cleaning according to a given schedule and the ability to return to the base for recharging on time, this intelligent assistant can independently build cleaning trajectories. Since the floor can contain a variety of obstacles, such as chairs and wires, the robot must constantly scan the path ahead and avoid such obstacles.
In order for a self-created robot to be able to execute various commands, manufacturers provide for the possibility of programming it. Having compiled an algorithm for the behavior of the robot in various conditions, you should create a code for the interaction of sensors with the outside world. This is possible due to the presence of a microcomputer, which is the brain center of such a mechanical robot.
Mobile mechanism of own production
Even without specialized, and usually expensive, kits, it is quite possible to make mechanical manipulator improvised means. So, having caught fire with the idea of \u200b\u200bcreating a robot, you should carefully analyze the stocks of home bins for the presence of unclaimed spare parts that can be used in this creative undertaking. Will go:
- a motor (for example, from an old toy);
- wheels from toy cars;
- designer details;
- carton boxes;
- fountain pen refills;
- adhesive tape of different types;
- glue;
- buttons, beads;
- screws, nuts, paper clips;
- all kinds of wires;
- light bulbs;
- battery (suitable for the motor voltage).
Tip: "It's a good skill when building a robot to be able to handle a soldering iron, because it will help to securely fasten the mechanism, especially electrical components."
With the help of these publicly available components, you can create a real technical miracle.
So, in order to make your own robot from materials available at home, you should:
- prepare the found parts for the mechanism, check their performance;
- draw a layout of the future robot, taking into account the available equipment;
- fold the body for the robot from the designer or cardboard parts;
- glue or solder the parts responsible for the movement of the mechanism (for example, fasten the robot motor to the wheelbase);
- provide power to the motor by connecting it with a conductor to the corresponding contacts of the battery;
- complement the thematic decor of the device.
Tip: “Beady eyes for a robot, decorative wire antenna horns, spring legs, diode bulbs will help to animate even the most boring mechanism. These elements can be attached with glue or tape.
You can make the mechanism of such a robot in a few hours, after which it remains to come up with a name for the robot and present it to admiring viewers. Surely some of them will pick up an innovative idea and be able to make their own mechanical characters.
Famous smart machines
The cute robot Wall-E wins over the viewer of the film of the same name, forcing him to empathize with his dramatic adventures, while the Terminator demonstrates the power of a soulless invincible machine. Characters Star Wars- faithful droids R2D2 and C3PO accompany you on travels across the galaxy far, far away, and the romantic Werther even sacrifices himself in a fight with space pirates.
Outside of cinema, there are also mechanical robots. So, the world admires the skills of the humanoid robot Asimo, who can walk up the stairs, play football, serve drinks and say hello politely. The Spirit and Curiosity rovers are equipped with autonomous chemical laboratories, which made it possible to analyze samples of Martian soils. Unmanned robotic cars can move without human intervention, even along complex city streets with high risks of unforeseen events.
Perhaps it is from home attempts to create the first intelligent mechanisms that inventions will grow that will change the technical panorama of the future and the life of mankind.
Now, few people remember, unfortunately, that in 2005 there were Chemical Brothers and they had a wonderful video - Believe, where a robotic arm was chasing the hero of the video around the city.
Then I had a dream. Unrealizable at that time, because I didn’t have the slightest idea about electronics. But I wanted to believe - believe. 10 years have passed, and literally yesterday I managed to assemble my own robotic arm for the first time, put it into operation, then break it, fix it, and put it into operation again, and along the way make friends and gain self-confidence.
Attention, spoilers under the cut!
It all started with (hello, Master Kit, and thanks for allowing me to write on your blog!), Which was almost immediately found and selected after this article on Habré. The site says that even an 8-year-old child can assemble a robot - why am I worse? I just try my hand the same way.
First there was paranoia
As a true paranoid, I will immediately express the concerns that I initially had regarding the constructor. In my childhood, at first there were solid Soviet designers, then Chinese toys crumbling in my hands ... and then my childhood was over :(Therefore, from what remained in the memory of toys, it was:
- Will plastic break and crumble in your hands?
- Will the pieces fit snugly together?
- Not all parts will be included in the kit?
- Will the assembled structure be fragile and short-lived?
- Some parts will have to be finished with a file
- And some parts just won't be in the set
- And another part will initially not work, it will have to be changed
The details of the designer are not only perfectly suited to each other, but also thought out the moment that the details are almost impossible to mix up. True, with German pedantry, the creators set aside the screws exactly as much as needed, therefore, it is undesirable to lose screws on the floor or confuse “which one goes where” when assembling the robot.
Specifications:
Length: 228 mm
Height: 380 mm
Width: 160 mm
Assembly weight: 658 gr.
Nutrition: 4 D batteries
Lifted item weight: up to 100 gr
Backlight: 1 LED
Control type: wired remote control
Estimated build time: 6 hours
Movement: 5 collector motors
Protection of the structure during movement: ratchet
Mobility:
Grab Mechanism: 0-1,77""
Wrist movement: within 120 degrees
Elbow movement: within 300 degrees
Shoulder movement: within 180 degrees
Rotation on the platform: within 270 degrees
You will need:
- long nose pliers (can't do without them)
- side cutters (can be replaced with a paper cutter, scissors)
- crosshead screwdriver
- 4 D batteries
Important! About small details
Speaking of screws. If you have encountered a similar problem, and know how to make the assembly even more convenient - welcome to the comments. For now, I'll share my experience.Identical in function, but different in length, bolts and screws are quite clearly spelled out in the instructions, for example, in the middle photo below we see bolts P11 and P13. Or maybe P14 - well, that is, here again, I confuse them again. =)
You can distinguish between them: the instructions say which one is how many millimeters. But, firstly, you won’t sit with a caliper (especially if you are 8 years old and / or you simply don’t have one), and, secondly, you can only distinguish them in the end if you put them side by side, which may not come right away came to mind (didn't come to me, hehe).
Therefore, I will warn you in advance if you decide to assemble this or a similar robot yourself, here is a hint for you:
- or look at the fasteners in advance;
- or buy yourself more small screws, self-tapping screws and bolts so as not to sweat.
Also, don't throw anything away until you're done building. In the lower photo in the middle, between two parts from the body of the "head" of the robot, there is a small ring that almost flew into the trash along with other "offcuts". And this, by the way, is a holder for an LED flashlight in the “head” of the capture mechanism.
Assembly process
Instructions are included with the robot. extra words- only images and clearly cataloged and labeled parts.The parts bite off quite comfortably and do not require stripping, but I liked the idea of \u200b\u200bprocessing each part with a cardboard cutter and scissors, although this is not necessary.
The assembly starts with four of the five motors included in the design, which are a real pleasure to build: I just love gear mechanisms.
We found the motors neatly packed and “stuck” to each other - get ready to answer the child’s question why collector motors are magnetized (you can immediately in the comments! :)
Important: 3 out of 5 motor housings need screw nuts on the sides- in the future we will put the cases on them when assembling the hand. Side nuts are not needed only in the motor, which will go to the base of the platform, but in order not to remember which case goes where, it is better to drown the nuts in each of the four yellow cases at once. Only for this operation, pliers will be needed, in the future they will not be needed.
After about 30-40 minutes, each of the 4 motors was equipped with its own gear mechanism and housing. Everything is going to be no more difficult than Kinder Surprise was going to be in childhood, only much more interesting. Question for attention to the photo above: three of the four output gears are black, where is the white one? A blue and black wire should come out of its case. It's all there in the instructions, but I think it's worth paying attention to it again.
After you have all the motors in your hands, except for the “head”, you will start assembling the platform on which our robot will stand. It was at this stage that I realized that I had to be more thoughtful with screws and screws: as you can see in the photo above, two screws for fastening the motors together due to the side nuts were not enough for me - they were already screwed somewhere by me into depth of the already assembled platform. I had to improvise.
When the platform and the main part of the arm are assembled, the instruction will prompt you to proceed to the assembly of the grip mechanism, where small parts and moving parts - the most interesting!
But, I must say that this is where the spoilers will end and the video will begin, since I had to go to a meeting with a friend and I had to take the robot, which I could not finish in time, with me.
How to become the soul of the company with the help of a robot
Easily! When we continued assembling together, it became clear: to assemble the robot on our own - Very Nice. Working on the design together is doubly pleasant. Therefore, I can safely recommend this set for those who do not want to sit in a cafe for boring conversations, but want to see friends and have a good time. Moreover, it seems to me that team building with such a set - for example, assembly by two teams, for speed - is practically a win-win option.The robot came to life in our hands as soon as we finished the assembly. Unfortunately, I cannot convey our delight to you in words, but I think many here will understand me. When the structure that you have assembled yourself suddenly begins to live a full life - it's a thrill!
We realized that we were terribly hungry and went to eat. It was not far to go, so we carried the robot in our hands. And then another pleasant surprise awaited us: robotics is not only exciting. She gets even closer. As soon as we sat down at the table, we were surrounded by people who wanted to get to know the robot and collect the same one for themselves. Most of all, the guys liked to greet the robot “by the tentacles”, because it really behaves like a living one, and first of all, it’s a hand! In a word, the basic principles of animatronics have been mastered by users intuitively. Here's what it looked like:
Troubleshooting
Upon returning home, I was in for an unpleasant surprise, and it's good that it happened before the publication of this review, because now we will immediately discuss troubleshooting.Deciding to try to move the hand to the maximum amplitude, we managed to achieve a characteristic crack and failure of the functionality of the motor mechanism in the elbow. At first it upset me: well, a new toy, just assembled - and no longer works.
But then it dawned on me: if you just assembled it yourself, what was the matter? =) I know very well the set of gears inside the case, and in order to understand whether the motor itself broke down, or whether the case was simply not well fixed, you can load it without removing the motor from the board and see if the clicks continue.
This is where I felt like hereby robot master!
Having carefully disassembled the “elbow joint”, it was possible to determine that the motor runs smoothly without load. The case parted, one of the screws fell out (because the motor magnetized it), and if we continued to operate, the gears would be damaged - when disassembled, a characteristic “powder” of worn plastic was found on them.
It is very convenient that the robot did not have to be disassembled entirely. And it's cool, in fact, that the breakdown occurred due to not quite accurate assembly in this place, and not because of some factory difficulties: they were not found in my set at all.
Advice: the first time after assembly, keep a screwdriver and pliers handy - they can come in handy.
What can be brought up with this set?
Self confidence!Not only did I find common topics for communication with absolutely strangers, but I also managed to not only assemble, but also repair the toy myself! So, I can be sure: everything will always be ok with my robot. And this is a very pleasant feeling when it comes to favorite things.
We live in a world where we are terribly dependent on vendors, suppliers, service people, and the availability of free time and money. If you can do almost nothing, you will have to pay for everything, and most likely - overpay. The ability to fix the toy yourself, because you know how each node is arranged in it, is priceless. Let the child have such self-confidence.
Results
What we liked:- The robot assembled according to the instructions did not require debugging, it started immediately
- Details are almost impossible to mix up
- Strict cataloging and parts availability
- Instructions not to be read (images only)
- Lack of significant backlashes and gaps in the structures
- Ease of Assembly
- Ease of prevention and repair
- Last but not least: you assemble your own toy, Filipino children do not work for you
- More fasteners, stock
- Parts and spare parts to it so that it can be replaced if necessary
- More robots, different and complex
- Ideas that can be improved / attached / removed - in a word, the game does not end with the assembly! I really want it to continue!
Assembling a robot from this constructor is no more difficult than a puzzle or Kinder Surprise, only the result is much larger and caused a storm of emotions in us and those around us. Great set, thanks
Make a robot very simple Let's see what it takes to create a robot at home, in order to understand the basics of robotics.
Surely, after watching movies about robots, you often wanted to build your comrade in arms, but you didn’t know where to start. Of course, you will not be able to build a bipedal terminator, but we do not aim for this. Anyone who knows how to properly hold a soldering iron in their hands can assemble a simple robot and this does not require deep knowledge, although they will not interfere. Amateur robotics is not much different from circuit engineering, only much more interesting, because areas such as mechanics and programming are also affected here. All components are readily available and are not that expensive. So progress does not stand still, and we will use it to our advantage.
Introduction
So. What is a robot? In most cases this automatic device, which reacts to any actions environment. Robots can be controlled by a human or perform pre-programmed actions. Typically, the robot has a variety of sensors (distance, rotation angle, acceleration), video cameras, manipulators. The electronic part of the robot consists of a microcontroller (MC) - a microcircuit that contains a processor, a clock generator, various peripherals, RAM and permanent memory. There are a huge number of different microcontrollers in the world for different applications, and powerful robots can be assembled on their basis. For amateur buildings, AVR microcontrollers are widely used. They are by far the most accessible and on the Internet you can find many examples based on these MKs. To work with microcontrollers you need to be able to program in assembler or C and have a basic knowledge of digital and analog electronics. In our project, we will use C. Programming for MK is not much different from programming on a computer, the syntax of the language is the same, most of the functions are practically the same, and the new ones are quite easy to learn and convenient to use.
What do we need
To begin with, our robot will be able to simply go around obstacles, that is, repeat the normal behavior of most animals in nature. Everything we need to build such a robot can be found in radio engineering stores. Let's decide how our robot will move. I consider the tracks that are used in tanks to be the most successful, this is the most convenient solution, because the tracks have a greater cross-country ability than the wheels of the car and it is more convenient to control them (to turn, it is enough to rotate the tracks in different directions). Therefore, you will need any toy tank that has tracks that rotate independently of each other, you can buy one at any toy store for a reasonable price. From this tank, you only need a platform with tracks and motors with gearboxes, you can safely unscrew the rest and throw it away. We also need a microcontroller, my choice fell on the ATmega16 - it has enough ports for connecting sensors and peripherals, and in general it is quite convenient. You will also need to buy some radio components, a soldering iron, a multimeter.
Making a board with MK
In our case, the microcontroller will perform the functions of the brain, but we will not start with it, but with the power supply of the robot's brain. Proper nutrition is a guarantee of health, so we will start with how to properly feed our robot, because novice robot builders usually make mistakes on this. And in order for our robot to work normally, you need to use a voltage stabilizer. I prefer the L7805 chip - it is designed to output a stable voltage of 5V, which is what our microcontroller needs. But due to the fact that the voltage drop on this chip is about 2.5V, a minimum of 7.5V must be supplied to it. Together with this stabilizer, electrolytic capacitors are used to smooth out voltage ripples and a diode must be included in the circuit to protect against polarity reversal.
Now we can work on our microcontroller. The case of the MK is DIP (it’s more convenient to solder) and has forty pins. On board there is an ADC, PWM, USART and many other things that we will not use for now. Consider a few important nodes. The RESET output (the 9th leg of the MK) is pulled up by the resistor R1 to the "plus" of the power source - this must be done! Otherwise, your MK may unintentionally reset or, in other words, fail. It is also desirable, but not mandatory, to connect RESET through ceramic capacitor C1 to ground. In the diagram, you can also see a 1000 uF electrolyte, it saves you from voltage drops when the engines are running, which will also have a positive effect on the operation of the microcontroller. Crystal resonator X1 and capacitors C2, C3 should be placed as close as possible to the XTAL1 and XTAL2 pins.
I won’t talk about how to flash MK, since you can read about it on the Internet. We will write the program in C, I chose CodeVisionAVR as the programming environment. It's quite a handy environment and useful for beginners because it has a built-in code generation wizard.
Motor control
An equally important component in our robot is the motor driver, which makes it easier for us to control it. Never and under no circumstances should motors be connected directly to the MK! In general, powerful loads cannot be controlled directly from the microcontroller, otherwise it will burn out. Use key transistors. For our case, there is a special chip - L293D. In such simple projects, always try to use this particular chip with the “D” index, as it has built-in diodes for overload protection. This chip is very easy to manage and easy to get in radio engineering stores. It is available in two DIP and SOIC packages. We will use in a DIP package because of the ease of mounting on the board. The L293D has separate motor and logic power supplies. Therefore, we will power the microcircuit itself from the stabilizer (VSS input), and the motors directly from batteries (VS input). L293D can withstand a load of 600 mA per channel, and it has two of these channels, that is, two motors can be connected to one microcircuit. But to be on the safe side, we will combine the channels, and then we need one mic for each engine. It follows that the L293D will be able to withstand 1.2 A. To achieve this, you need to combine the legs of the micro, as shown in the diagram. The microcircuit works as follows: when a logical “0” is applied to IN1 and IN2, and a logical unit is applied to IN3 and IN4, the motor rotates in one direction, and if the signals are inverted, a logical zero is applied, then the motor will start to rotate in the opposite direction. Pins EN1 and EN2 are responsible for turning on each channel. We connect them and connect them to the "plus" power supply from the stabilizer. Since the microcircuit heats up during operation, and installing radiators is problematic on this type of case, heat removal is provided by GND legs - it is better to solder them on a wide contact area. That's all you need to know about motor drivers for the first time.
Obstacle sensors
So that our robot can navigate and not crash into everything, we will install two infrared sensor. The simplest sensor consists of an IR diode that emits in the infrared spectrum and a phototransistor that will receive a signal from the IR diode. The principle is this: when there is no obstacle in front of the sensor, the IR rays do not fall on the phototransistor and it does not open. If there is an obstacle in front of the sensor, then the rays from it are reflected and fall on the transistor - it opens and current begins to flow. The disadvantage of such sensors is that they can react differently to various surfaces and are not protected from interference - from extraneous signals from other devices, the sensor may accidentally work. Signal modulation can protect against interference, but for now we will not bother with this. For starters, that's enough.
Robot firmware
To revive the robot, you need to write firmware for it, that is, a program that would take readings from sensors and control engines. My program is the most simple, it does not contain complex structures and everyone will understand. The next two lines include header files for our microcontroller and commands for generating delays:
#include
#include
The following lines are conditional because the PORTC values depend on how you connected the motor driver to your microcontroller:
PORTC.0 = 1; PORTC.1 = 0; PORTC.2 = 1; PORTC.3 = 0; A value of 0xFF means that the output will be a log. "1", and 0x00 is a log. "0". With the following construction, we check if there is an obstacle in front of the robot and on which side it is: if (!(PINB & (1< If light from an IR diode hits the phototransistor, then a log is set on the leg of the microcontroller. "0" and the robot starts moving back to move away from the obstacle, then turns around so as not to collide with the obstacle again and then goes forward again. Since we have two sensors, we check the presence of an obstacle twice - on the right and on the left, and therefore we can find out which side the obstacle is on. The "delay_ms(1000)" command indicates that one second will elapse before the next command starts executing. I have covered most of the aspects that will help you build your first robot. But the robotics doesn't end there. If you assemble this robot, then you will have a lot of opportunities to expand it. You can improve the algorithm of the robot, such as what to do if the obstacle is not on one side, but right in front of the robot. It also does not hurt to install an encoder - a simple device that will help you accurately position and know the location of your robot in space. For clarity, it is possible to install a color or monochrome display that can show useful information - the battery charge level, the distance to the obstacle, various debugging information. The improvement of sensors will not interfere - the installation of TSOP (these are IR receivers that perceive a signal of only a certain frequency) instead of conventional phototransistors. In addition to infrared sensors, there are ultrasonic ones, which are more expensive, and also not without drawbacks, but have recently been gaining popularity among robot builders. In order for the robot to respond to sound, it would be nice to install microphones with an amplifier. But the really interesting thing, I think, is installing the camera and programming machine vision based on it. There is a set of special OpenCV libraries with which you can program face recognition, movements on colored beacons, and a lot of other interesting things. It all depends on your imagination and skills. List of components: ATmega16 in DIP-40 package> L7805 in TO-220 package L293D in DIP-16 package x2 pcs. resistors with a power of 0.25 W with denominations: 10 kOhm x1 pcs., 220 Ohm x4 pcs. ceramic capacitors: 0.1 uF, 1 uF, 22 pF electrolytic capacitors: 1000 uF x 16 V, 220 uF x 16V x2 pcs. diode 1N4001 or 1N4004 16 MHz quartz resonator IR diodes: any in the amount of two pieces will do. phototransistors, also any, but reacting only to the wavelength of IR rays Firmware code: At the moment my robot is almost complete. It has a wireless camera, a distance sensor (both the camera and this sensor are installed on a rotary tower), an obstacle sensor, an encoder, a signal receiver from the remote control and an RS-232 interface for connecting to a computer. It works in two modes: autonomous and manual (receives control signals from the remote control), the camera can also be turned on / off remotely or by the robot itself to save battery power. I am writing a firmware for the protection of the apartment (image transfer to a computer, motion detection, detour of the premises). Many of us who have encountered computer technology have dreamed of building our own robot. For this device to perform some household duties, for example, bring beer. Everyone immediately takes up the creation of the most complex robot, but often quickly breaks off in the results. Our first robot, which was supposed to make a lot of chips, we never brought to mind. Therefore, you need to start with a simple one, gradually complicating your beast. Now we will tell you how you can create a simple do-it-yourself robot that will move independently around your apartment. Concept We set ourselves a simple task, to make a simple robot. Looking ahead, I’ll say that we managed, of course, not fifteen minutes, but a much longer period. But still it can be done in one evening. Usually such crafts are made for years. People run around the shops in search of the right gear for several months. But we immediately realized - this is not our way! Therefore, we will use in the construction of such details that can be easily found at hand, or uprooted from old technology. As a last resort, buy for pennies in any radio store or market. Another idea was to make our craft as cheap as possible. A similar robot is in electronic stores and costs from 800 to 1500 rubles! Moreover, it is sold in the form of parts, but it will still have to be assembled, and it is not a fact that after that it will also work. Manufacturers of such kits often forget to put some detail and that's it - the robot is lost along with the money! Why do we need such happiness? Our robot should be no more than 100-150 rubles in details, including motors and batteries. At the same time, if you pick out motors from an old children's car, then its price will generally be about 20-30 rubles! You feel what savings, while getting a great friend. The next part was what our handsome man would do. We decided to make a robot that will look for light sources. If the light source turns, then our car will steer after it. This concept is called “a robot striving to live.” It will be possible for him to replace the batteries with solar cells and then he will look for light to drive. Required parts and tools What do we need to make our child? Since the concept is from improvised means, we will need a circuit board, or even an ordinary thick cardboard. In the cardboard, you can make holes with an awl for attaching all the details. We will use a montage, because it turned out to be at hand, and you won’t find a cardboard box in my house during the day with fire. This will be the chassis on which we will mount the rest of the robot harness, mount the motors and sensors. As a driving force, we will use three or five volt motors that can be picked out of an old typewriter. We will make wheels from caps from plastic bottles, for example from Coca-Cola. Three-volt phototransistors or photodiodes are used as sensors. They can be picked out even from an old optomechanical mouse. It has infrared sensors (in our case, they were black). There they are paired, that is, two photocells in one bottle. With a tester, nothing prevents you from finding out which leg is for what. Our control element will be domestic 816G transistors. We use three finger-type batteries soldered together as power sources. Or you can take the battery compartment from the old machine, as we did. Wiring will be required for installation. For these purposes, twisted-pair wires are ideal, which should be piled up in the house of any self-respecting hacker. To fix all the details, it is convenient to use hot glue with a heat gun. This wonderful invention melts quickly and sets just as quickly, which allows you to quickly work with it and mount simple elements. The thing is ideal for such crafts and I have used it more than once in my articles. We also need a hard wire, an ordinary paper clip will do for it. We mount the circuit So, we took out all the details and put them on our table. The soldering iron is already smoldering with rosin and you are rubbing your hands, craving the assembly, well, then let's get started. We take a piece of montage and cut it to the size of the future robot. For cutting textolite we use scissors for metal. We made a square with a side of about 4-5 cm. The main thing is that our meager scheme, batteries for two engines and fasteners for the front wheel fit on it. So that the board does not shaggy and is even, you can process it with a file, and also remove sharp edges. Our next step is to solder the sensors. Phototransistors and photodiodes have a plus and a minus, in other words an anode and a cathode. It is necessary to observe the polarity of their inclusion, which is easy to determine with a simple tester. If you make a mistake, nothing will burn, but the robot will not drive. The sensors are soldered into the corners of the circuit board on one side so that they look to the sides. You don’t need to solder them completely into the board, but leave about one and a half centimeters of leads so that you can easily bend them in any direction - we will need this later when setting up our robot. These will be our eyes, they should be on one side of our chassis, which in the future will be in front of the robot. It can be immediately noted that we are assembling two control circuits: one for controlling the right and the second for the left engines. A little further away from the front edge of the chassis, next to our sensors, we need to solder the transistors. For the convenience of sealing and assembling the further circuit, we soldered both transistors “looking” with their marking towards the right wheel. Immediately it should be noted the location of the legs of the transistor. If you take the transistor in your hands and turn the metal substrate towards you, and the marking towards the forest (as in a fairy tale), and the legs are directed downwards, then from left to right the legs will be respectively: base, collector and emitter. If you look at the diagram where our transistor is shown, then the base will be a stick perpendicular to a thick segment in a circle, the emitter will be a stick with an arrow, the collector will be the same stick, only without an arrow. Everything seems to be clear here. Let's prepare the batteries and proceed to the direct assembly of the electrical circuit. Initially, we simply took three AA batteries and soldered them in series. You can immediately insert them into a special battery holder, which, as we have already said, is pulled out of an old children's car. Now we solder the wires to the batteries and define two key points on our board where all the wires will converge. This will be a plus and a minus. We did it simply - we passed the twisted pair to the edges of the board, soldered the ends to the transistors and photo sensors, made a twisted loop and soldered the batteries there. Perhaps not the best option, but the most convenient. Well, now we are preparing the wires, and proceed to the assembly of electricians. We will go from the positive pole of the battery to the negative contact, throughout the electrical circuit. We take a piece of twisted pair, and start walking - we solder the positive contact of both photo sensors to the plus of the batteries, and solder the emitters of transistors in the same place. We solder the second leg of the photocell with a small piece of wire to the base of the transistor. The remaining, last legs of the transjuk are soldered to the engines, respectively. The second contact of the motors can be soldered to the battery through the switch. But like true Jedi, we decided to turn on our robot by soldering and unsoldering the wire, since there was no switch of the right size in my bins. Electrical Debugging Everything, we have assembled the electrical part, now let's start testing the circuit. We turn on our circuit, and bring it to a lit table lamp. In turn, turning one or the other photocell. And let's see what happens. If our engines begin to rotate in turn at different speeds, depending on the lighting, then everything is in order. If not, then look for jambs in the assembly. Electronics is the science of contacts, which means that if something does not work, then somewhere there is no contact. An important point: the right photo sensor is responsible for the left wheel, and the left one, respectively, for the right one. Now, we figure out in which direction the right and left motors rotate. They should both spin forward. If this does not happen, then it is necessary to change the polarity of turning on the engine, which is spinning in the wrong direction, simply by soldering the wires at the motor terminals in reverse. We once again evaluate the location of the motors on the chassis and check the direction of movement in the direction where our sensors are installed. If everything is in order, then we'll move on. In any case, this can be corrected, even after everything is finally assembled. Device assembly We figured out the dreary electrical part, now let's get down to the mechanics. We will make wheels from caps, from plastic bottles. To make the front wheel, take two covers and glue them together. We glued the hollow part inwards around the perimeter, for greater stability of the wheel. Further, exactly in the center of the cover, we drill a hole in the first and second cover. For drilling and all sorts of home crafts, it is very convenient to use a dremel - a sort of small drill with a lot of nozzles, milling, cutting and many others. It is very convenient to use it for drilling holes less than one millimeter, where a conventional drill cannot cope. After we drill the covers, we thread a pre-bent paper clip into the hole. We bend the paper clip in the shape of the letter “P”, where the wheel dangles on the upper bar of our letter. Now we fix this paper clip between the photo sensors, in front of our car. The paperclip is convenient in that you can easily adjust the height of the front wheel, and we will deal with this adjustment later. Let's move on to the driving wheels. We will also make them from covers. Similarly - we drill each wheel strictly in the center. It is best that the drill be the size of the motor axis, and ideally - a fraction of a millimeter less so that the axis is inserted there, but with difficulty. We put both wheels on the shaft of the engines, and so that they do not jump off, we fix them with hot glue. This is important to do not only so that the wheels do not fly off when driving, but also do not rotate at the place of fasteners. The most critical part is the fastening of electric motors. We put them at the very end of our chassis, on the opposite side of the circuit board, relative to the rest of the electronics. It must be remembered that the controlled engine is placed opposite its control photosystem. This is done so that the robot can turn into the light. On the right is the photo sensor, on the left is the engine and vice versa. To begin with, we will intercept the engines with pieces of twisted pair, threaded through the holes in the mounting and twisted from above. We supply power, and look where our engines rotate. In a dark room, the motors will not rotate, it is advisable to point them at the lamp. Check if all engines are running. We turn the robot, and watch how the motors change their rotation speed depending on the lighting. Let's turn it with the right photo sensor, and the left engine should spin quickly, and the other one, on the contrary, will slow down. Finally, we check the direction of rotation of the wheels so that the robot moves forward. If everything works as we described, then you can carefully fix the engines with hot glue. We try to make sure that their wheels are on the same axis. That's it - we fix the batteries on the top platform of the chassis and proceed to setting up and playing with the robot. Pitfalls and setup The first pitfall in our craft was unexpected. When we assembled the whole circuit and the technical part, all the engines reacted perfectly to the light, and everything seemed to be going fine. But when we put our robot on the floor, it didn’t go with us. It turned out that the power of the motors is simply not enough. I had to urgently dismantle the children's car in order to get more powerful engines from there. By the way, if you take motors from toys, you definitely won’t go wrong with its power, since they are designed to carry a lot of cars with batteries. When we figured out the engines, we moved on to tuning and cosmetic drive. First you need to collect the beards of wires that we drag along the floor, and fix them on the chassis with hot glue. If the robot is dragging somewhere belly, then you can raise the front chassis by bending the fastening wire. The most important photosensors. It is best to bend them looking to the side at thirty degrees from the main course. Then he will catch the light sources, and go to them. The desired bending angle will have to be selected experimentally. That's it, we arm ourselves with a table lamp, put the robot on the floor, turn it on and start checking and enjoying how your child clearly follows the light source, and how cleverly he finds it. Improvements There is no limit to perfection and you can add functions to our robot indefinitely. There were even thoughts to install a controller, but then the cost and complexity of manufacturing would increase significantly, and this is not our method. The first improvement is to make a robot that would follow a given path. Everything is simple here, a black stripe is taken and printed on the printer, or similarly drawn with a black permanent marker on a piece of drawing paper. The main thing is that the strip should be slightly narrower than the width of the soldered photo sensors. We lower the photocells themselves down so that they look at the floor. Next to each of our eyes, we install a super-bright LED in series with a resistance of 470 ohms. The LED itself with resistance is soldered directly to the battery. The idea is simple, the light is perfectly reflected from a white sheet of paper, hits our sensor and the robot goes straight. As soon as the beam hits the dark strip, almost no light hits the photocell (black paper absorbs light perfectly), and therefore one engine starts to rotate more slowly. Another motor quickly turns the robot, leveling the course. As a result, the robot rides on a black strip, as if on rails. You can draw such a strip on the white floor and send the robot to the kitchen for beer from your computer. The second idea is to complicate the circuit by adding two more transistors and two photosensors and make the robot look for light not only from the front, but also from all sides, and as soon as it finds it, it rushes towards it. Everything will only depend on which side the light source appears: if it is in front, it will go forward, and if it is behind, it will roll back. Even in this case, to simplify the assembly, you can use the LM293D chip, but it costs about a hundred rubles. But with the help of it, you can easily configure the differential inclusion of the direction of rotation of the wheels, or, more simply, the direction of movement of the robot: forward and backward. The last thing you can do is to completely remove the batteries that are constantly running low and put in a solar battery, which you can now buy in a mobile phone accessories store (or on a dial-extreme). To exclude the complete loss of the robot's capacity in this mode, if it accidentally enters the shade, you can connect a solar battery in parallel - an electrolytic capacitor of a very large capacity (thousands of microfarads). Since the voltage we have there does not exceed five volts, the capacitor can be taken rated at 6.3 volts. With such a capacity and such a voltage, it will be quite miniature. Conders can either be bought or uprooted from old power supplies. conclusions So we have joined the greatest science, the engine of progress - cybernetics. In the seventies of the last century, it was very popular to design such robots. It should be noted that our creation uses the rudiments of analog computing, which died out with the advent of digital technologies. But as I have shown in this article, all is not lost. I hope we will not stop at designing such a simple robot, but will come up with new and new designs, and surprise us with your interesting crafts. Good luck with the build! Aug 27, 2017 GennadyConclusion
The rest of the possible variations, we think, you can come up with yourself. If there is something interesting - be sure to write.
