Tutorial on using a servo to make a car. A complete guide to assembling a servo-driven car for beginners.

People who make utensils can understand the obvious by observing the subtleties. Now there is a young man, holding a steering gear, looking around aimlessly, and asking: How can you make a car out of this small thing? Although this question is simple, it contains the mechanism of the movement of heaven and earth, and the principle of nature's transformation and education of all things. We, the people, must trace its fundamental origins, explore the context of its development, and use the technology we have today to forge the path forward for tomorrow. The road to the future starts with the wheels turning under your feet and the questions that arise in your heart. Try to look at this steering gear. In just a small space, it can perform countless changes. When the control mechanical device makes a slight sound and the wheels turn slowly, a whole new world opens.

First of all, before building a car, you should look at its materials. The steering gear is not an ordinary motor. An ordinary motor rotates when the power is turned on, in a repetitive cycle, tirelessly.This is not the case with the steering gear. It has a hidden ingenuity inside it. It has a positioning function, can control the angle, and can limit the stroke.. If you use this to make a car, then the car will have spirituality and can turn and turn, not just go straight.However, the steering gear is inherently excellent but lacks power. It rotates slowly and has soft momentum. If you want to carry a heavy load and carry a long distance, it is not something it can do.. Therefore, this car is an object for recreation and a tool for exploring subtleties. It is not meant to carry heavy weight for long distances. It is slow and smooth. It is not a fast running horse, but a leisurely stroll in a quiet courtyard. When you start building a car, you should understand this truth, and then you can talk about building a car. You must have a firm opinion in your mind, a measuring standard in your hand, and all the materials and equipment before you can start work. Anyone who makes tools must first make his tools sharp. The quality of materials is related to the success or failure of the appliance. When choosing materials, it is like choosing a fine horse. You must observe its muscles and bones to identify its quality before you can expect it to travel thousands of miles.

The foundation of a vehicle's appearance lies in its structure. That structure is the skeleton of the car. If bones are not formed, how can flesh and blood adhere to them? A common method is to use acrylic boards or wooden boards as the foundation, fix them with screws, or tie them up with cable ties. The shape of the structure does not need to be too rigid. It should be either square or round, simple or complex. The key is that the center of gravity can be stable and the layout should be consistent.The steering gear is to the structure just like the heart is to the body. It must be in a key position and fixed without moving.. If the frame is loose, it will be unstable when driving; if the frame is unbalanced, it will be inflexible when rotating. Therefore, when a good craftsman builds a structure, he will definitely measure its size and consider its center of gravity, and only after careful consideration will it be determined. Most of the shapes and styles that are usually used to make small cars are two-wheel drive. The bottom of the steering gear is connected to the wheel hub, and the rubber tire is attached to the outside of the wheel hub. When choosing rubber tires, you should choose thin ones instead of thick ones, and choose soft ones instead of hard ones. If it is thin, it will be light, if it is soft, it will grip the ground. The position of the steering gear must be symmetrical on the left and right, and the height should be kept equal. If the left and right sides are out of balance, the car will drive like a drunkard, swaying from side to side; if the height is inconsistent, the car will drive like a lame horse, stumbling and unable to move forward. The skills involved cannot be fully understood by those who have experienced it personally. The principles of making utensils are similar to the methods of learning. A little difference can lead to big mistakes. Therefore, a gentleman must be cautious from the beginning when making utensils.

A chassis with lightness as the key point was born. The wooden sheets were cut into a rectangular shape, with a width of about three inches and a length of about five inches. This is the basis for load-bearing. Select two servos, place them on the left and right sides respectively, and secure them firmly with screws, or use double-sided tape to ensure that they do not shake at all. If the chassis is too thick, then the power of the steering gear will not be enough. Even if it is operated at full strength, it will be like climbing a mountain with a heavy burden, and every step forward will be difficult. Second, the order of connection is to install the steering gear first and then the wheel hub, and first process the wheel hub and then install the tires. The shaft of the steering gear is made of metal and has teeth on it; the inside of the hub also has matching teeth. When installing, be sure to align the tooth patterns, push it in slowly, and then lock it with screws. If the tooth patterns are misaligned, the two will be loose and unreliable; if the screws are not firmly fixed, they will fall off during operation. Third, the universal wheel is something that plays a leading and auxiliary role. It is placed on the front end of the chassis and is either locked with screws or bonded with hot melt glue. This kind of wheel is extremely flexible and can be turned according to the situation. It will not compete with the steering gear for credit, but will become a boost to the steering gear. Without this wheel, the front of the car will drop to the ground, causing friction and obstruction. Even if the steering gear is turned, the body will not move, which will only increase the feeling of helplessness.

In today's era, the methods of making cars are no longer as crude as they used to be.There is an intelligent chip called a microcontroller, which seems to be where the heart of the car is.. Although this chip is small in size, it has various functions. The steering gear is like the muscles and bones; the microcontroller is like the mind. The mind gives instructions, and the muscles and bones respond to it, so that the car becomes intelligent. People who are just beginning to learn are often confused by electronic control methods, thinking that it is profound and difficult to fathom. But the things in the world can be summarized in one sentence if you know the key points; if you don't understand the key points, they will be scattered everywhere without a clue. To connect the microcontroller to the servo, only three wires are used: one is called the positive wire, which is bright red in color and must be connected to the positive terminal of the power supply; the second is called the negative wire, which is brown or black in color and must be connected to the negative terminal of the power supply; the third is the signal-related wire, which may be yellow or white in color and must be connected to the pin position specified by the microcontroller. These three lines are the key to the operation of the steering gear. They are like the rules that permeate the world and the breath that connects the inside and outside. There must be no wrong connection. When wiring, your mind should be like calm water, and your hand movements should be like stroking the strings. Connect the vermilion positive wire to the red corresponding point, connect the dark brown or jet black negative wire to the black terminal, and let the signal wires be connected properly according to the corresponding position. Wise people in the past once said this: Within a small space, there is actually an extremely vast world contained within it. And this microcontroller is precisely the key hub between the world and the world.

There is such a device called a steering gear. It can not only walk freely and uniquely in the world, but its rotation has certain limits and its movement has a certain rhythm.. Common servos can be modified to be used for continuous rotation. There are two ways here: one way is to break the internal position-limiting components and remove the obstacles of the potentiometer through physical modification and production; the other way is to control it through programming, controlling the speed and direction of its rotation according to the different degrees of pulse width. The so-called pulse width refers to those instantaneous moments calculated in one millisecond. This value is usually in the range of one millisecond to two milliseconds. When the value is one thousand five microseconds, the servo will remain in the center position without rotating; when the value is lower than one thousand five microseconds, the left wheel will move forward rapidly; when the value is higher than one thousand five microseconds, the right wheel will run rapidly.If you want the servo to move forward, you can set the value of the left wheel to 1,030 microseconds and the right wheel to 1,070 microseconds. In the process of moving forward and backward, the car body will rotate on its own like dancing.. In terms of formations in ancient times, there were changes between regular soldiers and surprise soldiers; today's vehicle control situation has the principles of advancement and retreat. The armies of both sides faced each other, and their strength was evenly matched. Regular troops were used to resist the enemy, while surprise troops were used to win victory. The same is true for the control of small vehicles. When the vehicle is moving forward, the two wheels drive side by side, which is a regular vehicle; when the vehicle is turning, one wheel stops and the other wheel rotates, or one moves forward and the other retreats, which is a strange vehicle. This principle of retreat and advancement exists in the human heart. The methods and paths of making utensils are intertwined with the art of war. Those who are good at winning by surprise are as endless as heaven and earth, and as inexhaustible as rivers.

However, the principle of making a car is not just to achieve its appearance, it must be to use it skillfully and exist completely in one mind. There are certain limits for this car to be able to move and stop, and it won't work if you don't know how to program. These people who program are the soul of the car. A car without a soul is actually broken although its appearance remains; a car with life is a real car. When you first start learning programming, you can follow the example of the ancients who copied the Dharma posts, first select the ready-made code, carefully taste the charm of the code inside, understand the rules of its command flow, and explore the mechanism of its command operation. A common method is to use loop as the ontology. Within the scope of the loop, there are situations where signals are obtained, there are situations where judgment and reasoning are performed, and there are situations where instructions are issued. The steering gear rotates during these instructions. The principle of programming is like observing the entire situation before arranging troops; after issuing an order, then check the details. Why do you say that? To make the car move forward, you have to make the left and right servos turn in the same direction. If you want to make it turn, you must make one wheel turn slowly and the other wheel turn fast. The ingenuity here lies in the delay time. Delay time is a way of measuring time. The longer the delay time, The shorter the time, the more complicated the action of the machine. The longer the delay time, the simpler the action of the machine. The ingenuity is the ingenuity of nature. In a small space, in a very short moment, there is infinite wisdom hidden in this small chip, waiting for thoughtful people to knock on its door and open its mechanism.

There are three realms for people who study this sect: the initial realm is called tracing a cat and drawing a tiger, which involves drawing according to the shape of a gourd, just to be able to move without questioning the truth behind it. In this state, as long as you see the steering wheel buzzing and the wheels rolling forward, you will feel happy in your heart and think that you have understood the true meaning. The second realm is to know why it is like this and understand why it is like this. When observing the car at this time, you will no longer be confused by the superficial phenomena, and you will be able to gain insight into its internal structure and clearly understand its operating mechanism. Know why it moves forward, why it stops, why it turns, why it rotates. The third state is to use it with ease and ease, as if you can control everything. People who have reached this level can treat everything in the world as a car: one steering gear can make a unicycle, two steering gears can make a balance car, and four steering gears can make a four-wheel drive car. Maybe add sensors to let it follow the trail, or add Bluetooth to let it follow instructions from devices the size of the palm of your hand. Reaching the ultimate state is to remove the craftsmanship and gain the craftsmanship. What is ingenuity? Don't follow the ancients, don't be limited to existing methods, use your own ideas to make new utensils. These three realms advance step by step in order and cannot exceed levels. If you pursue beyond levels, it's like learning to run before you learn to walk. There's no way you won't fall down.

Q: What is the difference between a steering gear and an ordinary motor?

Answer: The steering gear has controllable angle and speed, and it has a feedback mechanism inside. This is not comparable to the blind rotation of ordinary motors.. Its precise positioning ability is like a gentleman's words and deeds having a certain scale.

Q: Is a microcontroller necessary to drive the servo?

Answer: Not so. You can use a servo tester, or a handmade pulse generator, both of which can be used to drive it. However, if you want to obtain intelligent control, microcontroller is the only choice.

Question: Why is the servo changed to continuous rotation?

Answer: By changing it, it can make a full circle like a wheel, breaking through the original limitations. This involves repairing old objects and making full use of them, turning ordinary materials into extraordinary appliances.

Question: Why doesn’t the car go in a straight line?

Yes, there will definitely be minor differences in the servos. Certain means need to be taken to correct it, either by adjusting the pulse in the program, or by using physical methods to fine-tune the chassis. For uneven conditions in the equipment, manpower must be relied on to make up for it.

Question: What kind of power supply should be selected to power the steering gear car?

Answer: An ordinary five-volt DC power supply will suffice, but the current must be sufficient. It is common to use a power bank or a dry battery pack. The power supply must be sufficient to ensure that the operation will not slacken.

Q: What is the key to programming the servo?

Answer: When delay and pulse cooperate with each other, each servo will act in sequence, slowing down when it needs to be slow, and speeding up when it needs to be urgent. The ingenuity contained in this lies in the careful planning and control of chronological order.

There are ways to make tools, and the forks in the road are in many difficult situations. As soon as the edge is revealed, the entire body of the vehicle falls apart, or the wheel axle becomes skewed. The device that controls the direction makes a neighing sound like a trapped beast, and the lines are entangled with each other like messy twine. This is the first taste of countless flavors. You must remember that this is not the result of failure, but the food that helps you enter the path of spiritual practice. Every failure is a mental exercise. , every time you review and analyze, it is an improvement in your own conduct. In the past, you used the device that controls the direction of the ship as a game. In the future, you may use it as a sword to walk in various places. The principles between the world are heading to the same destination but the paths are different. You get the same result but the way of thinking is diverse. You start from a small game of iron tools and finally reach the ingenuity of nature. Although the device that controls the direction is very small, it can guide the vitality of the world. When the stars are covered with dark blue night sky, when the wheels of the car drive through the dust again, you and I will see that what is gradually moving is not only the steel and circuits, but also an unswerving ambition and an indelible soul. This soul condenses under the wheel and floats in the wind. When all the machines quiet down, it will still shine in the endless darkness, illuminating the little heart. Today, we are standing in the field of intelligence, looking at this car turned from a small piece of iron, just like the ancients saw fire. Although it is as weak as a bean, the tendency of blazing fire to start a prairie fire has already been nurtured in it.