Arduino Uno practical operation of powering micro-servos and detailed practical guide for avoiding pits

I once heard that there is a saying in "Kaogong Ji" that the sky has its specific season, the earth has its unique charm, the materials have excellent qualities, and the craftsmen have exquisite skills. Only when these four are combined can we create excellent works.

Now, you are holding the Arduino uno board and the micro steering gear in your hand, and you are thinking about how to adapt the power supply.

You set up a trial case for the first time.

Take the UNO board powered by the desktop power supply used daily and test it.

Directly connect the onboard 5V pin to feed the ordinary 9g micro servo.

When measured without load, the steering gear rotates smoothly without any obstruction.

Then drive a tiny load of 20g and place it at the end of the servo rocker arm.

You can see that the temperature of the onboard LDO voltage regulator chip has risen sharply by more than two degrees.。

Suddenly, glitches and glitches appeared in the UNO analog port data collection.

You can try to use the method of connecting an external constant voltage DC3A output and specially equipped with a corresponding 5V power supply, and connect it directly to the PIN pin of the servo.

Take a common ground wire and connect the voltage stabilizing terminal to the GND of the Uno board tightly.

Looking at the steering gear driving a 100g load, there was no erratic movement or loss of control.

The temperature rise of the onboard voltage stabilizing chip is completely the same as that of the no-load state.

The two groups were tested dozens of times and the results were completely consistent.

As the old saying goes: "If a worker wants to do his job well, he must first sharpen his tools."

Most of the new disciples in the world just use onboard pins for power supply.。

Unexpectedly, the peak current at the moment when the micro steering gear is blocked can reach more than twice the rated value.

The maximum native voltage regulator of the board is only a few hundred milliamps.

A piece of equipment that can withstand instantaneous surges without damaging core processing.

Isn’t the effect of contrasting what is measured by observing the directions extremely obvious?

If you are holding an experimental board that exhibits the characteristic properties of the first-generation replica, the thickness of the copper foil traces on this experimental board is less than one inch of copper weight. In this case, you rashly rely on the onboard 5V voltage of this experimental board to directly drive three small micro-rudders to move in parallel at the same time. Then, in less than three minutes, you will definitely see signs of over-temperature burn marks on the voltage stabilizing block on this experimental board. Since such a situation has already occurred, why didn't we know earlier that we needed to adopt an avoidance strategy?

When such a situation arises, it is common sense to handle it carefully and make complete plans and careful considerations in advance. The first-generation replica test board had its own unique characteristics and inherent limitations. The thickness of the copper foil traces failed to reach one inch of copper weight, which showed that it had a certain degree of vulnerability in carrying current and other related aspects.Simply using the onboard 5V to directly drive three small micro-rudders to move in parallel undoubtedly put more pressure on the experimental board than it could bear, causing over-temperature burn marks in the voltage stabilizing area on the board.. If we had foreseen it earlier and taken appropriate measures in advance, we might have been able to prevent such adverse consequences.

There are beginners in the world who don’t know what they are doing.

Directly combine three or four micro servos on a development board.

As soon as the power is turned on, there will be a peculiar smell and the panels will be scrapped and damaged.

I have seen and heard of hundreds of such regrets every year.

In contrast, look at those students who have reserved independent power supplies. Even if the equipment they control is connected to drive ten small rudders, there is not even a single sway. With such an outstanding performance, who among them is better and who is worse does not need to spend more words to defend.

arduino uno power microservoThe core secret lies entirely in the subtlety of matching the pulse capacitance to the current carrying limit in a small space. The principles and key points contained in it need to be grasped accurately. A slight deviation may affect the operation of the entire system.

During the testing process of electronic projects, you must firmly adhere to the bottom line principle of "separate power supply". Only by acting in accordance with this principle can you avoid going in the wrong direction, avoid detours, promote smoother project progress, and reduce unnecessary time and energy consumption.

You have now summarized the questions and answers to frequently asked questions at the end of the article for easy immediate reference:

A: When you only have Arduino uno at hand, it is just used as a power supply device. In this case, and there is no external power cord, can a single servo in a small no-load state be driven directly?

A: The short-term no-load debugging period can be used for temporary purposes. The temperature rise needs to be monitored throughout the entire process to prevent overload situations. Once the specified time is exceeded, the risk will inevitably increase rapidly, leading to component damage.

Q: Is this small step of sharing land really insignificant and can be skipped?

A: The requirement of a common ground wire must be strictly implemented. Once the level reference is out of order, the servo control signal will be lost. In this case, the entire experiment will be completely invalid.

Q: When connecting to an external power supply, do I need to install additional large capacitor components on the power supply port?

A: Connecting 100 microfarad filter capacitors in parallel has excellent performance in stabilizing current and can significantly reduce spikes, thus extending the service life of the servo development board.

Question: When a general external 5V mobile phone charging head is used as a smaller servo power supply, can it be used directly?

A: To choose a regular head with a rated output of more than 1.5A, you must avoid products that cost 100 yuan, are slow, have no fast charging function, and are compatible with old components, otherwise the power supply will be unstable.

This sentence is clearly recorded in "Xunzi Encouraging Learning": "The accumulation of good deeds will lead to virtue, and the gods will be satisfied, and the holy heart will be ready." This sentence deeply explains the principle of developing noble character through continuous accumulation of good deeds. For a person, when he persists in accumulating good deeds for a long time, his own spiritual level can be sublimated. In this way, a mind with the wisdom and character of a saint will naturally become complete.

There is no room for luck in electronic production technology. The subtleties of every experiment will produce results that will lead to long-term and stable operation in the future.

There is absolutely no room for utilization in the technology of electronic production. All kinds of details, during the experiment process, will bring long-term results and stable operation in the future.

Do your tests quickly.

Be sure to follow the law of independent power supply.

We ensure that every project is carried out smoothly and smoothly.

There is no regret or regret caused by the unnecessary burning of previous cars several generations ago.