Small homemade robot. Creating a robot at home Simple DIY robots for beginners
Make a robot very simple Let's figure out what it takes to create a robot at home, in order to understand the basics of robotics.
Surely, after watching enough movies about robots, you have often wanted to build your own comrade in battle, but you didn’t know where to start. Of course, you won't be able to build a bipedal Terminator, but that's not what we're trying to achieve. Anyone who knows how to hold a soldering iron correctly in their hands can assemble a simple robot and this does not require deep knowledge, although it will not hurt. Amateur robotics is not much different from circuit design, only much more interesting, because it also involves areas such as mechanics and programming. All components are easily 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 is an automatic device that responds to any actions environment. Robots can be controlled by humans or perform pre-programmed actions. Typically, the robot is equipped with a variety of sensors (distance, rotation angle, acceleration), video cameras, and 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 on their basis you can assemble powerful robots. For amateur buildings wide application found AVR microcontrollers. 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 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 language syntax is the same, most functions are practically no different, and 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 avoid 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 stores. Let's decide how our robot will move. I consider the most successful tracks to be those used in tanks; these are the most convenient solution, because the tracks have greater maneuverability than the wheels of the car and are more convenient to control (to turn, it is enough to rotate the tracks in different directions). Therefore, you will need any toy tank whose tracks rotate independently of each other, you can buy one at any toy store at a reasonable price. From this tank you only need a platform with tracks and motors with gearboxes, the rest you can safely unscrew and throw away. We also need a microcontroller, my choice fell on ATmega16 - it has enough ports for connecting sensors and peripherals and in general it is quite convenient. You will also need to purchase some radio components, a soldering iron, and 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 powering the robot’s brain. Proper nutrition- a guarantee of health, so we will start with how to properly feed our robot, because this is where novice robot builders usually make mistakes. And in order for our robot to work normally, we need to use a voltage stabilizer. I prefer the L7805 chip - it is designed to produce a stable 5V output voltage, which is what our microcontroller needs. But due to the fact that the voltage drop on this microcircuit 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 is necessarily included in the circuit to protect against polarity reversal.
Now we can move on to 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 much more that we will not use for now. Let's look at a few important nodes. The RESET pin (9th leg of the MK) is pulled up by resistor R1 to the “plus” of the power source - this must be done! Otherwise, your MK may unintentionally reset or, more simply put, glitch. Also a desirable measure, but not mandatory, is to connect RESET through the ceramic capacitor C1 to ground. In the diagram you can also see a 1000 uF electrolyte; it saves you from voltage dips when the engines are running, which will also have a beneficial effect on the operation of the microcontroller. Quartz resonator X1 and capacitors C2, C3 should be located as close as possible to pins XTAL1 and XTAL2.
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. This is a fairly user-friendly environment and is useful for beginners because it has a built-in code creation 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 microcircuit is very easy to control and is easy to get in radio stores. It is available in two packages: DIP and SOIC. We will use DIP in the package due to the ease of mounting on the board. L293D has separate power supply for motors and logic. Therefore, we will power the microcircuit itself from the stabilizer (VSS input), and the motors directly from the 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 chip. But to be on the safe side, we will combine the channels, and then we will need one micra for each engine. It follows that the L293D will be able to withstand 1.2 A. To achieve this, you need to combine the micra legs, as shown in the diagram. The chip works in the following way: when a logical “0” is applied to IN1 and IN2, and a logical one is applied to IN3 and IN4, the motor rotates in one direction, and if the signals are inverted and a logical zero is applied, then the motor will begin to rotate in the other direction. Pins EN1 and EN2 are responsible for turning on each channel. We connect them and connect them to the “plus” of the power supply from the stabilizer. Since the microcircuit heats up during operation, and installing radiators on this type of case is problematic, heat dissipation is provided by GND legs - it is better to solder them on a wide contact pad. That's all you need to know about engine drivers for the first time.
Obstacle sensors
So that our robot can navigate and not crash into everything, we will install two infrared sensor. Most the simplest sensor consists of an IR diode that emits in the infrared spectrum and a phototransistor that will receive the signal from the IR diode. The principle is this: when there is no obstacle in front of the sensor, the IR rays do not hit the phototransistor and it does not open. If there is an obstacle in front of the sensor, then the rays are reflected from it and hit 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 - the sensor may accidentally trigger from extraneous signals from other devices. Modulating the signal can protect you from interference, but we won’t bother with that for now. 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 the motors. My program is the simplest, 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; The value 0xFF means that the output will be log. "1", and 0x00 is log. "0". With the following construction we check whether 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 installed on the microcontroller leg. “0” and the robot starts moving backward to move away from the obstacle, then turns around so as not to collide with the obstacle again and then moves forward again. Since we have two sensors, we check for 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 command "delay_ms(1000)" indicates that one second will pass before the next command begins to execute. I've covered most of the aspects that will help you build your first robot. But robotics doesn't end there. If you assemble this robot, you will have a lot of opportunities to expand it. You can improve the robot's algorithm, such as what to do if the obstacle is not on some side, but right in front of the robot. It also wouldn’t 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 - battery charge level, distance to obstacles, various debugging information. It wouldn't hurt to improve the sensors - installing TSOPs (these are IR receivers that perceive a signal only of a certain frequency) instead of conventional phototransistors. In addition to infrared sensors, there are ultrasonic sensors, which are more expensive and also have their drawbacks, but have recently been gaining popularity among robot builders. In order for the robot to respond to sound, it would be a good idea to install microphones with an amplifier. But what I think is really interesting is installing the camera and programming machine vision based on it. There is a set of special OpenCV libraries with which you can program facial recognition, movement according to colored beacons and many other interesting things. It all depends only on your imagination and skills. List of components: ATmega16 in DIP-40 package> L7805 in TO-220 package L293D in DIP-16 housing x2 pcs. resistors with a power of 0.25 W with ratings: 10 kOhm x 1 pc., 220 Ohm x 4 pcs. ceramic capacitors: 0.1 µF, 1 µF, 22 pF electrolytic capacitors: 1000 µF x 16 V, 220 µF x 16 V x 2 pcs. diode 1N4001 or 1N4004 16 MHz quartz resonator IR diodes: any two of them will do. phototransistors, also any, but responding only to the wavelength of infrared rays Firmware code: At the moment my robot is almost complete. It is equipped with a wireless camera, a distance sensor (both the camera and this sensor are installed on a rotating tower), an obstacle sensor, an encoder, a signal receiver from the remote control and an RS-232 interface for connecting to a computer. It operates 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 firmware for apartment security (transferring images to a computer, detecting movements, walking around the premises). How to make a robot at home so that everything works out? You need to start simple and gradually complicate it! Instructions for creating robots with your own hands at home literally flooded the Internet. The author of the article will not remain aloof from this. In general, this process can be divided into three parts: theoretical, preparatory and actual assembly. Within the framework of the article, all of them will be considered, and the general scheme for developing a cleaner will be described. To develop from scratch, you need knowledge about current, voltage, and the functioning of various elements such as triggers, capacitors, resistors, transistors. You should also learn how to solder all this on circuits and use connecting wires. It is necessary to work out every aspect of movement and execution of actions, achieving maximum detail in actions to achieve your goal. And this knowledge is necessary if you are really interested in how to make a robot at home, and not just idle curiosity. Before you start figuring out how to make a robot at home, you need to take good care of the conditions in which it will be assembled. First you need to prepare a workplace where the desired device will be created. It is necessary to place the structure itself and its constituent parts somewhere. You should also consider the issue of convenient placement of the soldering iron, rosin and solder. The workplace should be as optimized as possible so that it provides convenience when interacting with the structure. It is necessary to think over the “backbone” of the structure on which everything will be built. Usually one part is selected, and all the others are soldered to it. Speaking about the quality of soldering, it should be said that the places where it will be carried out must be cleaned. Also, depending on the thickness of the wires and legs used, it is necessary to select a sufficient amount of solder so that the elements do not fall off during operation. To simplify signal transmission processes and prevent the possibility of a short circuit, it can be etched. Then all the necessary elements are applied to it, the resulting structure is connected to a power source and, if necessary, the device is modified. How to make something easy at home? And also useful? You need to keep your home clean, and it is advisable to automate this process. Of course, it is difficult to create a full-fledged cleaning robot, but a minimal design that will ensure the collection of dust from the floors of rooms is quite possible. To be honest, we will consider one that works in one place and at the same time removes small debris located in the dislocation zone. To create such a design, you must have the following materials: Drill holes for the brushes at equal distances. Attach them. It is desirable that all brushes be placed at an equal distance from the others and the center of the plate. Using bolts and nuts, an adjusting fastener should be attached to each of them, and they themselves are fixed with their help. The adjusting fastener sliders should be set to the middle position. We will use fans for movement. We connect them to the battery and place them in parallel so that they ensure the robot rotates in a circle. This design will be used as a vibration motor. Throw on the terminals and the structure is ready for use. If the robot moves to the side during the cleaning process, work with the adjustment fasteners. The design presented in the article does not require significant financial costs or skills and experience. When creating the robot, inexpensive materials were used, obtaining which is not a significant problem. If you want to complicate the design and make it move purposefully, you will need improvements in the form of additional motors and microcontrollers. Here's how to make a robot at home. Just think how much you can improve here! The widest field for design activities. Surely, after watching enough movies about robots, you have often wanted to build your own comrade in battle, but you didn’t know where to start. Of course, you won't be able to build a bipedal Terminator, but that's not what we're trying to achieve. Anyone who knows how to hold a soldering iron correctly in their hands can assemble a simple robot and this does not require deep knowledge, although it will not hurt. Amateur robotics is not much different from circuit design, only much more interesting, because it also involves areas such as mechanics and programming. All components are easily available and are not that expensive. So progress does not stand still, and we will use it to our advantage. In our case, the microcontroller will perform the functions of the brain, but we will not start with it, but with powering the robot’s brain. Proper nutrition is the key to health, so we will start with how to properly feed our robot, because this is where novice robot builders usually make mistakes. And in order for our robot to work normally, we need to use a voltage stabilizer. I prefer the L7805 chip - it is designed to produce a stable 5V output voltage, which is what our microcontroller needs. But due to the fact that the voltage drop on this microcircuit 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 is necessarily included in the circuit to protect against polarity reversal. #include The following lines are conditional because the PORTC values depend on how you connected the motor driver to your microcontroller: PORTC.0 = 1; The value 0xFF means that the output will be log. “1”, and 0x00 is log. "0". With the following construction we check whether 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 installed on the microcontroller leg. “0” and the robot starts moving backward to move away from the obstacle, then turns around so as not to collide with the obstacle again and then moves forward again. Since we have two sensors, we check for 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 command "delay_ms(1000)" indicates that one second will pass before the next command begins to execute. MK type: ATmega16 #include Void main(void) //Configure output ports //Main loop of the program. Here we read the values from the sensors According to your wishes, I am posting a video: UPD. I re-uploaded the photos and made some minor corrections to the text. Who wouldn’t want to have a universal assistant, ready to carry out any assignment: wash the dishes, buy groceries, change a tire on the car, and take children to kindergarten and 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 are already helping a person with household chores: a robot vacuum cleaner will clean up while the owners are at work, a multicooker will help prepare food, no worse than a self-assembled tablecloth, and the playful puppy Aibo will happily bring slippers or a ball. Sophisticated robots are used in manufacturing, medicine and space. They make it possible to partially, or even completely, replace human labor in difficult or dangerous conditions. At the same time, androids try to look like people in appearance, while industrial robots are usually created for economic and technological reasons and external decor is by no means a priority for them. But it turns out that you can try to make a robot using improvised means. So, you can construct an original mechanism from a telephone handset, a computer mouse, a toothbrush, an old camera or the ubiquitous plastic bottle. By placing several sensors on the platform, you can program such a robot to perform simple operations: adjusting the lighting, sending 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 a handicraft business. One of the easiest solutions to making a robot is to purchase a ready-made robotics kit with step-by-step instructions. This option is also suitable for those who are going to seriously engage in technical creativity, because one package contains all the necessary parts for mechanics: from electronic boards and specialized sensors, to a supply of bolts and stickers. Along with instructions allowing you to create a rather complex mechanism. Thanks to many accessories, such a robot can serve as an excellent base for creativity. Basic school knowledge in physics and skills from labor lessons are quite enough to assemble the first robot. A variety of sensors and motors are controlled by control panels, and special programming environments make it possible to create real cyborgs that can execute commands. For example, a sensor on 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. Such a robot will never fall off the table! By the way, real robot vacuum cleaners work on a similar principle. In addition to carrying out cleaning according to a given schedule and the ability to return to the base on time to recharge, this intelligent assistant can independently build trajectories for cleaning the room. Because there may be a variety of obstacles on the floor, 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 carry out various commands, manufacturers provide the possibility of programming it. Having drawn up an algorithm for the robot’s behavior in various conditions, you should create a code for the interaction of sensors with the outside world. This is possible thanks to the presence of a microcomputer, which is the brain center of such a mechanical robot. Even without specialized, and usually expensive, kits, it is quite possible to make a mechanical manipulator using improvised means. So, having been inspired by the idea of creating 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. They will use: Advice: “A useful skill when creating a robot is the ability to use a soldering iron, because it will help securely fasten the mechanism, especially the 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: Advice: “Beady eyes for a robot, decorative horns-antennae made of wire, legs-springs, diode light 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 all that remains is to come up with a name for the robot and present it to admiring spectators. Surely some of them will pick up the innovative idea and be able to make their own mechanical characters. Mechanical robots also exist outside of cinema. Thus, the world admires the skills of the humanoid robot Asimo, who can walk up the stairs, play football, serve drinks and greet politely. The Spirit and Curiosity rovers are equipped with autonomous chemical laboratories, which made it possible to analyze samples of Martian soils. Self-driving robotic cars can move without human intervention, even on complex city streets with high risks of unexpected events. Perhaps it is from home attempts to create the first intellectual mechanisms that inventions will grow that will change the technical panorama of the future and the life of mankind. We usually talk about robots created by various research centers or companies. However, robots are being assembled by ordinary people around the world with varying degrees of success. So today we present to you ten homemade robots.
A German neurobiology student assembled an android named Adam. Its name stands for Advanced Dual Arm Manipulator or “advanced two-handed manipulator.” The robot's arms have five degrees of freedom. They are powered by Robolink joints from the German company Igus. External cables are used to rotate Adam's joints. In addition, Adam's head is equipped with two video cameras, a loudspeaker, a speech synthesizer, and an LCD panel that imitates the movements of the robot's lips.
The MPR-1 robot is notable for the fact that it is not constructed of iron or plastic, like most of its counterparts, but of paper. According to the creator of the robot, artist Kikousya, the materials for the MPR-1 are paper, several dowels and a couple of rubber bands. At the same time, the robot moves confidently, although its mechanical elements are also made of paper. The crank mechanism ensures the movement of the robot's legs, and its feet are designed so that their surface is always parallel to the floor.
The Boxie robot was created by American engineer Alexander Reben from the Massachusetts Institute of Technology. Boxie, somewhat similar to the famous cartoon character Wall-E, should help media workers. The small and nimble paparazzi is made entirely of cardboard, it moves using caterpillars, and navigates the street using ultrasound, which helps it overcome various obstacles. The robot conducts interviews in a funny, childish voice, and the respondent can interrupt the conversation at any time by pressing a special button. Boxie can record about six hours of video and send it to its owner using the nearest Wi-Fi point.
Norwegian engineer Kare Halvorsen created a six-legged robot called Morphex, which can transform into a ball and back. In addition, the robot is able to move. The movement of the robot occurs due to motors pushing it forward. The robot moves in an arc rather than in a straight line. Due to its design, Morphex cannot independently correct its trajectory. Halvorsen is currently working to resolve this issue. An interesting update is expected: the creator of the robot wants to add 36 LEDs that would allow Morphex to change colors.
Americans Tim Heath and Ryan Hickman decided to create a small robot based on an Android phone. The robot they created, Truckbot, is quite simple in terms of its design: the HTC G1 phone is on top of the robot, being its “brain”. At the moment, the robot can move on a flat surface, choose directions of movement and accompany all sorts of phrases with collisions with obstacles.
One day, American Brian Dorey, who was developing expansion boards, was faced with the following problem: it is very difficult to solder a double-row pin comb with his own hands. Brian needed an assistant, so he decided to create a robot that could solder. It took Brian two months to develop the robot. The completed robot is equipped with two soldering irons that can solder two rows of contacts at the same time. You can control the robot via a PC and tablet.
Every family has its own favorite hobby. For example, the family of American engineer Robert Beatty designs robots. Robert is helped by his teenage daughters, and his wife and newborn daughter provide them with moral support. Their most impressive creation is the self-propelled Mechatronic Tank. Thanks to its 20 kg armor, this security robot is a threat to any criminal. Eight echolocators mounted on the robot's turret allow it to calculate the distance to objects in its field of view with an accuracy of an inch. The robot also shoots metal bullets at a speed of a thousand rounds per minute.
An American named Max created a mini-copy of the famous one. Max made the supporting structure of the robot from scraps of five-millimeter acrylic glass, and to fasten all the parts together he used ordinary threaded bolts. In addition, when creating the robot, miniature servos were used, which are responsible for the movement of its limbs, as well as parts from the Arduino Mega kit, which coordinate the motor process of the mechanical dog.
The robotic bun was designed by Jerome Demers and runs on solar batteries. There is a capacitor inside the robot that is connected to the solar power parts. It is needed to accumulate energy in bad weather. When there is enough solar energy, the ball begins to roll forward.
Initially, Georgia Tech professor Gil Weinberg designed a robotic arm for a drummer whose arm was amputated. Gil then created automated synchronization technology that would allow a two-armed drummer to use a robotic arm as an extra arm. The robotic arm reacts to the drummer's playing style, creating its own rhythm. The robotic arm can also improvise, while analyzing the rhythm in which the drummer plays.Conclusion
Creating a robot at home
Preparatory processes
Assembly
Simple robot
Introduction
So. What is a robot? In most cases, this is an automatic device that responds to any environmental actions. Robots can be controlled by humans or perform pre-programmed actions. Typically, the robot is equipped with a variety of sensors (distance, rotation angle, acceleration), video cameras, and 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 on their basis you can assemble powerful robots. AVR microcontrollers are widely used for amateur buildings. 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 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 language syntax is the same, most functions are practically no different, and 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 avoid 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 stores. Let's decide how our robot will move. I think the most successful are the tracks that are used in tanks; this is the most convenient solution, because the tracks have greater maneuverability than the wheels of a vehicle and are more convenient to control (to turn, it is enough to rotate the tracks in different directions). Therefore, you will need any toy tank whose tracks rotate independently of each other, you can buy one at any toy store at a reasonable price. From this tank you only need a platform with tracks and motors with gearboxes, the rest you can safely unscrew and throw away. We also need a microcontroller, my choice fell on ATmega16 - it has enough ports for connecting sensors and peripherals and in general it is quite convenient. You will also need to purchase some radio components, a soldering iron, and a multimeter. Making a board with MK
Robot diagram
Now we can move on to 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 much more that we will not use for now. Let's look at a few important nodes. The RESET pin (9th leg of the MK) is connected by resistor R1 to the “plus” of the power source - this must be done! Otherwise, your MK may unintentionally reset or, more simply put, glitch. Also a desirable measure, but not mandatory, is to connect RESET through the ceramic capacitor C1 to ground. In the diagram you can also see a 1000 uF electrolyte; it saves you from voltage dips when the engines are running, which will also have a beneficial effect on the operation of the microcontroller. Quartz resonator X1 and capacitors C2, C3 should be located as close as possible to pins XTAL1 and XTAL2.
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. This is a fairly user-friendly environment and is useful for beginners because it has a built-in code creation wizard.
My robot boardMotor 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 microcircuit is very easy to control and is easy to get in radio stores. It is available in two packages: DIP and SOIC. We will use DIP in the package due to the ease of mounting on the board. L293D has separate power supply for motors and logic. Therefore, we will power the microcircuit itself from the stabilizer (VSS input), and the motors directly from the 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 chip. But to be on the safe side, we will combine the channels, and then we will need one micra for each engine. It follows that the L293D will be able to withstand 1.2 A. To achieve this, you need to combine the micra legs, as shown in the diagram. The microcircuit works as follows: when a logical “0” is applied to IN1 and IN2, and a logical one is applied to IN3 and IN4, the motor rotates in one direction, and if the signals are inverted and a logical zero is applied, then the motor will begin to rotate in the other direction. Pins EN1 and EN2 are responsible for turning on each channel. We connect them and connect them to the “plus” of the power supply from the stabilizer. Since the microcircuit heats up during operation, and installing radiators on this type of case is problematic, heat removal is ensured by GND legs - it is better to solder them on a wide contact pad. That's all you need to know about engine drivers for the first time. Obstacle sensors
So that our robot can navigate and not crash into everything, we will install two infrared sensors on it. The simplest sensor consists of an IR diode that emits in the infrared spectrum and a phototransistor that will receive the signal from the IR diode. The principle is this: when there is no obstacle in front of the sensor, the IR rays do not hit the phototransistor and it does not open. If there is an obstacle in front of the sensor, then the rays are reflected from it and hit the transistor - it opens and current begins to flow. The disadvantage of such sensors is that they can react differently to different surfaces and are not protected from interference - the sensor may accidentally be triggered by extraneous signals from other devices. Modulating the signal can protect you from interference, but we won’t bother with that for now. For starters, that's enough. 
The first version of my robot's sensorsRobot firmware
To revive the robot, you need to write firmware for it, that is, a program that would take readings from sensors and control the motors. My program is the simplest, it does not contain complex structures and will be understandable to everyone. The next two lines include header files for our microcontroller and commands for generating delays:
#include
PORTC.1 = 0;
PORTC.2 = 1;
PORTC.3 = 0;
...
} Conclusion
I've covered most of the aspects that will help you build your first robot. But robotics doesn't end there. If you assemble this robot, you will have a lot of opportunities to expand it. You can improve the robot's algorithm, such as what to do if the obstacle is not on some side, but right in front of the robot. It also wouldn’t 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 - battery charge level, distance to obstacles, various debugging information. It wouldn't hurt to improve the sensors - installing TSOPs (these are IR receivers that perceive a signal only of a certain frequency) instead of conventional phototransistors. In addition to infrared sensors, there are ultrasonic sensors, which are more expensive and also have their drawbacks, but have recently been gaining popularity among robot builders. In order for the robot to respond to sound, it would be a good idea to install microphones with an amplifier. But what I think is really interesting is installing the camera and programming machine vision based on it. There is a set of special OpenCV libraries with which you can program facial recognition, movement according to colored beacons and many other interesting things. It all depends only on your imagination and skills. List of components:
Firmware code:
/*****************************************************
Firmware for the robot
Clock frequency: 16.000000 MHz
If your quartz frequency is different, then you need to specify this in the environment settings:
Project -> Configure -> "C Compiler" Tab
*****************************************************/
#include
{
//Configure input ports
//Through these ports we receive signals from sensors
DDRB=0x00;
//Turn on pull-up resistors
PORTB=0xFF;
//Through these ports we control the motors
DDRC=0xFF;
//and control the engines
while (1)
{
//Let's go forward
PORTC.0 = 1;
PORTC.1 = 0;
PORTC.2 = 1;
PORTC.3 = 0;
if (!(PINB & (1<
//Go backwards 1 second
PORTC.0 = 0;
PORTC.1 = 1;
PORTC.2 = 0;
PORTC.3 = 1;
delay_ms(1000);
//Wrap it up
PORTC.0 = 1;
PORTC.1 = 0;
PORTC.2 = 0;
PORTC.3 = 1;
delay_ms(1000);
}
if (!(PINB & (1<
//Go backwards 1 second
PORTC.0 = 0;
PORTC.1 = 1;
PORTC.2 = 0;
PORTC.3 = 1;
delay_ms(1000);
//Wrap it up
PORTC.0 = 0;
PORTC.1 = 1;
PORTC.2 = 1;
PORTC.3 = 0;
delay_ms(1000);
}
};
} About my robot
At the moment my robot is almost complete. 
It is equipped with a wireless camera, a distance sensor (both the camera and this sensor are installed on a rotating tower), an obstacle sensor, an encoder, a signal receiver from the remote control and an RS-232 interface for connecting to a computer. It operates 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 firmware for apartment security (transferring images to a computer, detecting movements, walking around the premises). 
Cyborg out of the box
Self-made mobile mechanism
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The cute robot Wall-E endears himself to the viewer of the film of the same name, making him empathize with his dramatic adventures, while the Terminator demonstrates the power of a soulless, invincible machine. Star Wars characters - the faithful droids R2D2 and C3PO - accompany you on journeys through a galaxy far, far away, and the romantic Werther even sacrifices himself in a battle with space pirates.Adam
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