Vedon Linux Video first two sections of the previous period watch the harvest

just read the first phase of Vedon Linux video, the main explanation of the arm of the Hardware Foundation, for me such a from the single-chip computer to turn over the person, indeed shocked!

I have read a lot of books and videos about SCM, but never one will be so concise. Yes, concise, summed up quite well.

First section schematic Gpio and gate circuit

In the first section, a brief introduction of some analog circuits, the content is simple, but the most useful part of the words.

(1) In the past in the mold electrical class, transistor this lesson but spent a considerable section, the results let people foggy, do not know how to use. But here, Vedon old

The division does not have the spare part, directly to the most direct, the most effective part gives us. P is positive, n is negative. When between B and E, if the P segment voltage is greater than n, the conduction is on. Guide

After the pass, that is the usual circuit view.

(2) pull-up resistor, why in the microcontroller, we in the input mode to be set as the pull-up resistor, and did not really think about it before. Vedon teacher simply has

It tells us the answer.

As you can see, when a switch is closed, the input end becomes 0V. When the switch is not closed, it is the pull-up resistance voltage, so as to determine the input voltage

Objective.

The second section of the schematic diagram of the Protocol class interface UART

From this verse, I feel the deepest two points. One is the protocol, the second is the level conversion chip.

(1) In the agreement, as the name implies, how to make the communication between the two sides agree. UART protocol settings, mainly divided into two aspects, one is the setting of some bits, such as the start bit has

Several, there is no check digit, stop a bit. Note here: The start of the transmission, the voltage is high or low, representing the start of the transmission, stop when the high voltage, cutting voltage to

For a certain amount of time to take effect.

(2) Baud rate, the maximum effect is to let the two sides of the communication port at a certain time to read the level.

Daily Word: Corresponding the corresponding async asynchronous parity mode check bit

Vedon Linux Video first two sections of the previous period watch the harvest