1

00:00:01,366 --> 00:00:05,800

This lesson talks about the reset circuit of the OLED screen touch circuit

2

00:00:07,233 --> 00:00:08,933

The reset signal is RESET

3

00:00:11,433 --> 00:00:14,400

Signals beginning with TS in the drawings represent touch

4

00:00:16,133 --> 00:00:19,066

_RESET and _N indicate active low

5

00:00:20,866 --> 00:00:23,200

Let's take Mi 9 Pro as an example to learn

6

00:00:25,100 --> 00:00:28,133

First find its touch connector J6400

7

00:00:29,866 --> 00:00:33,100

RESET is the reset signal, the touch reset signal

8

00:00:36,433 --> 00:00:39,300

This signal goes to pin 14 of the touch connector

9

00:00:41,300 --> 00:00:43,566

This touch connector is J6400

10

00:00:43,766 --> 00:00:47,800

One end of the reset signal is connected to pin 14 of the touch connector,

11

00:00:47,866 --> 00:00:50,533

and the other end is connected to the CPU

12

00:00:51,966 --> 00:00:55,100

The direction marked here is wrong, the normal should be like this

13

00:00:57,066 --> 00:01:00,133

The reset signal is for the CPU to reset the touch

14

00:01:00,266 --> 00:01:03,333

So everyone should pay attention to some wrong points in the drawings,

15

00:01:04,133 --> 00:01:05,600

let's mark them with a cross

16

00:01:06,866 --> 00:01:09,533

The other end of the reset comes from the CPU

17

00:01:10,400 --> 00:01:15,333

We double-clicked it and found that it came from pin AM33 of the chip U3100

18

00:01:17,833 --> 00:01:19,900

What kind of chip is U3100?

19

00:01:21,500 --> 00:01:26,466

The model of the chip is SM8150, which is Qualcomm's CPU

20

00:01:28,433 --> 00:01:32,166

In other words, this reset signal starts from the pin AM33 of the CPU

21

00:01:33,333 --> 00:01:37,033

and leads to the pin 14 of the touch connector J6400

22

00:01:37,933 --> 00:01:39,366

This is the channel of its line

23

00:01:40,366 --> 00:01:41,733

That's all for this lesson