SCM only accept digital signals, many books are saying, this sentence is true, but did not say thoroughly, so that our software engineers superficial information. In fact, the digital signal is a square wave signal we mentioned last, or other waveforms can be represented by 0 and 1.
But in real life we can have a little curve waveform, temperature changes so regular but irregular, such as Beijing Summer highest day temperature of 38 degrees, the lowest temperature of 25 degrees, the temperature that day will be between the maximum and minimum temperatures fluctuation. But the 38 degrees and 25 degrees microcontroller do not know, ah, how to? There are ways, this figure is to become a binary number, it is possible, but what a way to become a binary temperature, while we are unlikely to see the temperature to get hold of the side of the calculator to calculate the temperature change should not be very fast, some waveform is changing rapidly, such as sound waves. So we need a fast, timeliness of conversion.
In fact, the single-chip designers have this in mind, and now even some high-grade and low-grade Dian microcontrollers have such a conversion module, and has a special name called ADC, also known as analog to digital conversion module. The ADC module is responsible for continuously varying the waveform of the square wave into rules, the basic principle is to convert the irregular waveform amplitude variations into a voltage variation or the frequency variation, the ADC module has such a characteristic capable of handling current voltage Dian and frequency, in other words, it can convert the current value into Dian voltage and frequency corresponding to the binary number.
ADC module exists not only in the single-chip, and has a separate ADC chip. Functions are the same, but higher performance and accuracy.
ADC first introduced to this, follow-up will detail the ADC, because it is very important. thank you all!
No way with maps, scenic beach for everyone to take a right, thank you again!
