【米尔 MYD-YM62X 开发板入门评测】 4.KEY按键学习

andeyqi

本帖最后由 andeyqi 于 2023-11-12 23:04 编辑

板载按键(Key):
MYD-YM62X 有三个按键，S1 是 MCU 复位按键；S2 是 Soc 复位按键；S3 是用户按键，已经在设备树配置,原理图如下。

Linux 的/dev/input/eventx 设备可以用来方便地调试鼠标、键盘、触摸板等输入设备，开发板输入cat /proc/bus/input/devices 命令查看input 子系统信息，结果如下：

root@myd-am62x:/home/workspace/usb# cat /proc/bus/input/devices
I: Bus=0019 Vendor=0001 Product=0001 Version=0100
N: Name="gpio-keys"
P: Phys=gpio-keys/input0
S: Sysfs=/devices/platform/gpio-keys/input/input0
U: Uniq=
H: Handlers=event0
B: PROP=0
B: EV=100003
B: KEY=1 0 0 0 0

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从输出信息可知gpio-keys 对应的是event0事件，应用层读取/dev/input/event0 节点即可获取到按键状态，用户态通过input_event 结构体获取按键状态信息。

/*
* The event structure itself
* Note that __USE_TIME_BITS64 is defined by libc based on
* application's request to use 64 bit time_t.
*/
struct input_event {
#if (__BITS_PER_LONG != 32 || !defined(__USE_TIME_BITS64)) && !defined(__KERNEL__)
struct timeval time;
#define input_event_sec time.tv_sec
#define input_event_usec time.tv_usec
#else
__kernel_ulong_t __sec;
#if defined(__sparc__) && defined(__arch64__)
unsigned int __usec;
unsigned int __pad;
#else
__kernel_ulong_t __usec;
#endif
#define input_event_sec __sec
#define input_event_usec __usec
#endif
__u16 type;
__u16 code;
__s32 value;
};

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以下是官方文档对input_event 成员取值的描述:

.. _input-event-codes:
=================
Input event codes
=================
The input protocol uses a map of types and codes to express input device values
to userspace. This document describes the types and codes and how and when they
may be used.
A single hardware event generates multiple input events. Each input event
contains the new value of a single data item. A special event type, EV_SYN, is
used to separate input events into packets of input data changes occurring at
the same moment in time. In the following, the term "event" refers to a single
input event encompassing a type, code, and value.
The input protocol is a stateful protocol. Events are emitted only when values
of event codes have changed. However, the state is maintained within the Linux
input subsystem; drivers do not need to maintain the state and may attempt to
emit unchanged values without harm. Userspace may obtain the current state of
event code values using the EVIOCG* ioctls defined in linux/input.h. The event
reports supported by a device are also provided by sysfs in
class/input/event*/device/capabilities/, and the properties of a device are
provided in class/input/event*/device/properties.
Event types
===========
Event types are groupings of codes under a logical input construct. Each
type has a set of applicable codes to be used in generating events. See the
Codes section for details on valid codes for each type.
* EV_SYN:
- Used as markers to separate events. Events may be separated in time or in
space, such as with the multitouch protocol.
* EV_KEY:
- Used to describe state changes of keyboards, buttons, or other key-like
devices.
* EV_REL:
- Used to describe relative axis value changes, e.g. moving the mouse 5 units
to the left.
* EV_ABS:
- Used to describe absolute axis value changes, e.g. describing the
coordinates of a touch on a touchscreen.
* EV_MSC:
- Used to describe miscellaneous input data that do not fit into other types.
* EV_SW:
- Used to describe binary state input switches.
* EV_LED:
- Used to turn LEDs on devices on and off.
* EV_SND:
- Used to output sound to devices.
* EV_REP:
- Used for autorepeating devices.
* EV_FF:
- Used to send force feedback commands to an input device.
* EV_PWR:
- A special type for power button and switch input.
* EV_FF_STATUS:
- Used to receive force feedback device status.
Event codes
===========
Event codes define the precise type of event.
EV_SYN
------
EV_SYN event values are undefined. Their usage is defined only by when they are
sent in the evdev event stream.
* SYN_REPORT:
- Used to synchronize and separate events into packets of input data changes
occurring at the same moment in time. For example, motion of a mouse may set
the REL_X and REL_Y values for one motion, then emit a SYN_REPORT. The next
motion will emit more REL_X and REL_Y values and send another SYN_REPORT.
* SYN_CONFIG:
- TBD
* SYN_MT_REPORT:
- Used to synchronize and separate touch events. See the
multi-touch-protocol.txt document for more information.
* SYN_DROPPED:
- Used to indicate buffer overrun in the evdev client's event queue.
Client should ignore all events up to and including next SYN_REPORT
event and query the device (using EVIOCG* ioctls) to obtain its
current state.
EV_KEY
------
EV_KEY events take the form KEY_<name> or BTN_<name>. For example, KEY_A is used
to represent the 'A' key on a keyboard. When a key is depressed, an event with
the key's code is emitted with value 1. When the key is released, an event is
emitted with value 0. Some hardware send events when a key is repeated. These
events have a value of 2. In general, KEY_<name> is used for keyboard keys, and
BTN_<name> is used for other types of momentary switch events.
A few EV_KEY codes have special meanings:
* BTN_TOOL_<name>:
- These codes are used in conjunction with input trackpads, tablets, and
touchscreens. These devices may be used with fingers, pens, or other tools.
When an event occurs and a tool is used, the corresponding BTN_TOOL_<name>
code should be set to a value of 1. When the tool is no longer interacting
with the input device, the BTN_TOOL_<name> code should be reset to 0. All
trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name>
code when events are generated. Likewise all trackpads, tablets, and
touchscreens should export only one BTN_TOOL_<name> at a time. To not break
existing userspace, it is recommended to not switch tool in one EV_SYN frame
but first emitting the old BTN_TOOL_<name> at 0, then emit one SYN_REPORT
and then set the new BTN_TOOL_<name> at 1.
* BTN_TOUCH:
BTN_TOUCH is used for touch contact. While an input tool is determined to be
within meaningful physical contact, the value of this property must be set
to 1. Meaningful physical contact may mean any contact, or it may mean
contact conditioned by an implementation defined property. For example, a
touchpad may set the value to 1 only when the touch pressure rises above a
certain value. BTN_TOUCH may be combined with BTN_TOOL_<name> codes. For
example, a pen tablet may set BTN_TOOL_PEN to 1 and BTN_TOUCH to 0 while the
pen is hovering over but not touching the tablet surface.
Note: For appropriate function of the legacy mousedev emulation driver,
BTN_TOUCH must be the first evdev code emitted in a synchronization frame.
Note: Historically a touch device with BTN_TOOL_FINGER and BTN_TOUCH was
interpreted as a touchpad by userspace, while a similar device without
BTN_TOOL_FINGER was interpreted as a touchscreen. For backwards compatibility
with current userspace it is recommended to follow this distinction. In the
future, this distinction will be deprecated and the device properties ioctl
EVIOCGPROP, defined in linux/input.h, will be used to convey the device type.
* BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, BTN_TOOL_TRIPLETAP, BTN_TOOL_QUADTAP:
- These codes denote one, two, three, and four finger interaction on a
trackpad or touchscreen. For example, if the user uses two fingers and moves
them on the touchpad in an effort to scroll content on screen,
BTN_TOOL_DOUBLETAP should be set to value 1 for the duration of the motion.
Note that all BTN_TOOL_<name> codes and the BTN_TOUCH code are orthogonal in
purpose. A trackpad event generated by finger touches should generate events
for one code from each group. At most only one of these BTN_TOOL_<name>
codes should have a value of 1 during any synchronization frame.
Note: Historically some drivers emitted multiple of the finger count codes with
a value of 1 in the same synchronization frame. This usage is deprecated.
Note: In multitouch drivers, the input_mt_report_finger_count() function should
be used to emit these codes. Please see multi-touch-protocol.txt for details.
EV_REL
------
EV_REL events describe relative changes in a property. For example, a mouse may
move to the left by a certain number of units, but its absolute position in
space is unknown. If the absolute position is known, EV_ABS codes should be used
instead of EV_REL codes.
A few EV_REL codes have special meanings:
* REL_WHEEL, REL_HWHEEL:
- These codes are used for vertical and horizontal scroll wheels,
respectively. The value is the number of detents moved on the wheel, the
physical size of which varies by device. For high-resolution wheels
this may be an approximation based on the high-resolution scroll events,
see REL_WHEEL_HI_RES. These event codes are legacy codes and
REL_WHEEL_HI_RES and REL_HWHEEL_HI_RES should be preferred where
available.
* REL_WHEEL_HI_RES, REL_HWHEEL_HI_RES:
- High-resolution scroll wheel data. The accumulated value 120 represents
movement by one detent. For devices that do not provide high-resolution
scrolling, the value is always a multiple of 120. For devices with
high-resolution scrolling, the value may be a fraction of 120.
If a vertical scroll wheel supports high-resolution scrolling, this code
will be emitted in addition to REL_WHEEL or REL_HWHEEL. The REL_WHEEL
and REL_HWHEEL may be an approximation based on the high-resolution
scroll events. There is no guarantee that the high-resolution data
is a multiple of 120 at the time of an emulated REL_WHEEL or REL_HWHEEL
event.
EV_ABS
------
EV_ABS events describe absolute changes in a property. For example, a touchpad
may emit coordinates for a touch location.
A few EV_ABS codes have special meanings:
* ABS_DISTANCE:
- Used to describe the distance of a tool from an interaction surface. This
event should only be emitted while the tool is hovering, meaning in close
proximity of the device and while the value of the BTN_TOUCH code is 0. If
the input device may be used freely in three dimensions, consider ABS_Z
instead.
- BTN_TOOL_<name> should be set to 1 when the tool comes into detectable
proximity and set to 0 when the tool leaves detectable proximity.
BTN_TOOL_<name> signals the type of tool that is currently detected by the
hardware and is otherwise independent of ABS_DISTANCE and/or BTN_TOUCH.
* ABS_PROFILE:
- Used to describe the state of a multi-value profile switch. An event is
emitted only when the selected profile changes, indicating the newly
selected profile value.
* ABS_MT_<name>:
- Used to describe multitouch input events. Please see
multi-touch-protocol.txt for details.
* ABS_PRESSURE/ABS_MT_PRESSURE:
- For touch devices, many devices converted contact size into pressure.
A finger flattens with pressure, causing a larger contact area and thus
pressure and contact size are directly related. This is not the case
for other devices, for example digitizers and touchpads with a true
pressure sensor ("pressure pads").
A device should set the resolution of the axis to indicate whether the
pressure is in measurable units. If the resolution is zero, the
pressure data is in arbitrary units. If the resolution is non-zero, the
pressure data is in units/gram. For example, a value of 10 with a
resolution of 1 represents 10 gram, a value of 10 with a resolution of
1000 represents 10 microgram.
EV_SW
-----
EV_SW events describe stateful binary switches. For example, the SW_LID code is
used to denote when a laptop lid is closed.
Upon binding to a device or resuming from suspend, a driver must report
the current switch state. This ensures that the device, kernel, and userspace
state is in sync.
Upon resume, if the switch state is the same as before suspend, then the input
subsystem will filter out the duplicate switch state reports. The driver does
not need to keep the state of the switch at any time.
EV_MSC
------
EV_MSC events are used for input and output events that do not fall under other
categories.
A few EV_MSC codes have special meaning:
* MSC_TIMESTAMP:
- Used to report the number of microseconds since the last reset. This event
should be coded as an uint32 value, which is allowed to wrap around with
no special consequence. It is assumed that the time difference between two
consecutive events is reliable on a reasonable time scale (hours).
A reset to zero can happen, in which case the time since the last event is
unknown. If the device does not provide this information, the driver must
not provide it to user space.
EV_LED
------
EV_LED events are used for input and output to set and query the state of
various LEDs on devices.
EV_REP
------
EV_REP events are used for specifying autorepeating events.
EV_SND
------
EV_SND events are used for sending sound commands to simple sound output
devices.
EV_FF
-----
EV_FF events are used to initialize a force feedback capable device and to cause
such device to feedback.
EV_PWR
------
EV_PWR events are a special type of event used specifically for power
management. Its usage is not well defined. To be addressed later.
Device properties
=================
Normally, userspace sets up an input device based on the data it emits,
i.e., the event types. In the case of two devices emitting the same event
types, additional information can be provided in the form of device
properties.
INPUT_PROP_DIRECT + INPUT_PROP_POINTER
--------------------------------------
The INPUT_PROP_DIRECT property indicates that device coordinates should be
directly mapped to screen coordinates (not taking into account trivial
transformations, such as scaling, flipping and rotating). Non-direct input
devices require non-trivial transformation, such as absolute to relative
transformation for touchpads. Typical direct input devices: touchscreens,
drawing tablets; non-direct devices: touchpads, mice.
The INPUT_PROP_POINTER property indicates that the device is not transposed
on the screen and thus requires use of an on-screen pointer to trace user's
movements. Typical pointer devices: touchpads, tablets, mice; non-pointer
device: touchscreen.
If neither INPUT_PROP_DIRECT or INPUT_PROP_POINTER are set, the property is
considered undefined and the device type should be deduced in the
traditional way, using emitted event types.
INPUT_PROP_BUTTONPAD
--------------------
For touchpads where the button is placed beneath the surface, such that
pressing down on the pad causes a button click, this property should be
set. Common in Clickpad notebooks and Macbooks from 2009 and onwards.
Originally, the buttonpad property was coded into the bcm5974 driver
version field under the name integrated button. For backwards
compatibility, both methods need to be checked in userspace.
INPUT_PROP_SEMI_MT
------------------
Some touchpads, most common between 2008 and 2011, can detect the presence
of multiple contacts without resolving the individual positions; only the
number of contacts and a rectangular shape is known. For such
touchpads, the SEMI_MT property should be set.
Depending on the device, the rectangle may enclose all touches, like a
bounding box, or just some of them, for instance the two most recent
touches. The diversity makes the rectangle of limited use, but some
gestures can normally be extracted from it.
If INPUT_PROP_SEMI_MT is not set, the device is assumed to be a true MT
device.
INPUT_PROP_TOPBUTTONPAD
-----------------------
Some laptops, most notably the Lenovo 40 series provide a trackstick
device but do not have physical buttons associated with the trackstick
device. Instead, the top area of the touchpad is marked to show
visual/haptic areas for left, middle, right buttons intended to be used
with the trackstick.
If INPUT_PROP_TOPBUTTONPAD is set, userspace should emulate buttons
accordingly. This property does not affect kernel behavior.
The kernel does not provide button emulation for such devices but treats
them as any other INPUT_PROP_BUTTONPAD device.
INPUT_PROP_ACCELEROMETER
------------------------
Directional axes on this device (absolute and/or relative x, y, z) represent
accelerometer data. Some devices also report gyroscope data, which devices
can report through the rotational axes (absolute and/or relative rx, ry, rz).
All other axes retain their meaning. A device must not mix
regular directional axes and accelerometer axes on the same event node.
Guidelines
==========
The guidelines below ensure proper single-touch and multi-finger functionality.
For multi-touch functionality, see the multi-touch-protocol.rst document for
more information.
Mice
----
REL_{X,Y} must be reported when the mouse moves. BTN_LEFT must be used to report
the primary button press. BTN_{MIDDLE,RIGHT,4,5,etc.} should be used to report
further buttons of the device. REL_WHEEL and REL_HWHEEL should be used to report
scroll wheel events where available.
Touchscreens
------------
ABS_{X,Y} must be reported with the location of the touch. BTN_TOUCH must be
used to report when a touch is active on the screen.
BTN_{MOUSE,LEFT,MIDDLE,RIGHT} must not be reported as the result of touch
contact. BTN_TOOL_<name> events should be reported where possible.
For new hardware, INPUT_PROP_DIRECT should be set.
Trackpads
---------
Legacy trackpads that only provide relative position information must report
events like mice described above.
Trackpads that provide absolute touch position must report ABS_{X,Y} for the
location of the touch. BTN_TOUCH should be used to report when a touch is active
on the trackpad. Where multi-finger support is available, BTN_TOOL_<name> should
be used to report the number of touches active on the trackpad.
For new hardware, INPUT_PROP_POINTER should be set.
Tablets
-------
BTN_TOOL_<name> events must be reported when a stylus or other tool is active on
the tablet. ABS_{X,Y} must be reported with the location of the tool. BTN_TOUCH
should be used to report when the tool is in contact with the tablet.
BTN_{STYLUS,STYLUS2} should be used to report buttons on the tool itself. Any
button may be used for buttons on the tablet except BTN_{MOUSE,LEFT}.
BTN_{0,1,2,etc} are good generic codes for unlabeled buttons. Do not use
meaningful buttons, like BTN_FORWARD, unless the button is labeled for that
purpose on the device.
For new hardware, both INPUT_PROP_DIRECT and INPUT_PROP_POINTER should be set.

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input_event信息主要成员描述。

tpye 设备类型

用来描述event类型，我们本次实验主要会用到以下两个类型，EV_SYN和EV_KEY 两个事件，EV_SYN 用于分割事件标记代表上报按键事件的结束，EV_KEY ：用于描述键盘、按键或其他类似按键设备的状态变化。

* EV_SYN:
- Used as markers to separate events. Events may be separated in time or in
space, such as with the multitouch protocol.
* EV_KEY:
- Used to describe state changes of keyboards, buttons, or other key-like
devices.

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code

根据type 不同含义不同,本次实验会上报按键的code 码。

Event codes
===========
Event codes define the precise type of event.
EV_SYN
------
EV_SYN event values are undefined. Their usage is defined only by when they are
sent in the evdev event stream.
EV_KEY
------
EV_KEY events take the form KEY_<name> or BTN_<name>. For example, KEY_A is used
to represent the 'A' key on a keyboard. When a key is depressed, an event with
the key's code is emitted with value 1. When the key is released, an event is
emitted with value 0. Some hardware send events when a key is repeated. These
events have a value of 2. In general, KEY_<name> is used for keyboard keys, and
BTN_<name> is used for other types of momentary switch events.
A few EV_KEY codes have special meanings:
* BTN_TOOL_<name>:
- These codes are used in conjunction with input trackpads, tablets, and
touchscreens. These devices may be used with fingers, pens, or other tools.
When an event occurs and a tool is used, the corresponding BTN_TOOL_<name>
code should be set to a value of 1. When the tool is no longer interacting
with the input device, the BTN_TOOL_<name> code should be reset to 0. All
trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name>
code when events are generated. Likewise all trackpads, tablets, and
touchscreens should export only one BTN_TOOL_<name> at a time. To not break
existing userspace, it is recommended to not switch tool in one EV_SYN frame
but first emitting the old BTN_TOOL_<name> at 0, then emit one SYN_REPORT
and then set the new BTN_TOOL_<name> at 1.

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value

对应的事件的value值,1对应按键按下，0对应按键抬起。

实机验证：
我们在应用层添加如下测试代码，读取event0 节点的event数据，将读取到的数据打印输出。

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/input.h>
#include <unistd.h>
#include <time.h>
typedef struct input_event input;
#define MY_EVENT "/dev/input/event0"
int main() {
int fd = -1;
int ret = -1;
struct input_event ev = { 0 };
const int size = sizeof(input);
fd = open(MY_EVENT, O_RDONLY);
if (fd < 0) {
perror("open");
return -1;
}
while (1) {
ret = read(fd, &ev, size);
if (ret != size) {
close(fd);
return -1;
}
printf("type = %x, code = %x, value = %x\n", ev.type, ev.code,
ev.value);
struct tm t;
char date_time[64] = { 0 };
strftime(date_time, sizeof(date_time), "%Y-%m-%d %H:%M:%S",
localtime_r(&ev.time.tv_sec, &t));
printf("gettimeofday: date_time = %s\n", date_time);
}
close(fd);
}

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将上述程序交叉编译后上板运行输出结果如下。

上面log里的type 值分别为0和1,从如下代码type 的定义说明(myir-ti-linux-myd-am62x-linux-6.1.46\include\uapi\linux\input-event-codes.h)可知对应的分别为EV_SYN 和 EV_KEY 事件

/*
* Event types
*/
#define EV_SYN 0x00
#define EV_KEY 0x01
#define EV_REL 0x02
#define EV_ABS 0x03
#define EV_MSC 0x04
#define EV_SW 0x05
#define EV_LED 0x11
#define EV_SND 0x12
#define EV_REP 0x14
#define EV_FF 0x15
#define EV_PWR 0x16
#define EV_FF_STATUS 0x17
#define EV_MAX 0x1f
#define EV_CNT (EV_MAX+1)

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从上述的输出的日志可知对应的code值定义为0x100,这个值是在哪定义的呢，从设备树的gpio_key 节点可知，定义的值为linux,code = <BTN_0>。

gpio-keys {
compatible = "gpio-keys";
autorepeat;
pinctrl-names = "default";
pinctrl-0 = <&main_user_key_pins_default>;
user: user {
label = "GPIO Key USER1";
linux,code = <BTN_0>;
gpios = <&main_gpio0 36 GPIO_ACTIVE_LOW>;
};
};

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从上述的节点可知对应的linux,code = <BTN_0> 按键值定义的为BTN_0 从include\uapi\linux\input-event-codes.h 定义的button 键值可知BTN_0 定义的为0x100。

/* Code 255 is reserved for special needs of AT keyboard driver */
#define BTN_MISC 0x100
#define BTN_0 0x100
#define BTN_1 0x101
#define BTN_2 0x102
#define BTN_3 0x103
#define BTN_4 0x104
#define BTN_5 0x105
#define BTN_6 0x106
#define BTN_7 0x107
#define BTN_8 0x108
#define BTN_9 0x109
#define BTN_MOUSE 0x110
#define BTN_LEFT 0x110
#define BTN_RIGHT 0x111
#define BTN_MIDDLE 0x112
#define BTN_SIDE 0x113
#define BTN_EXTRA 0x114
#define BTN_FORWARD 0x115
#define BTN_BACK 0x116
#define BTN_TASK 0x117
#define BTN_JOYSTICK 0x120
#define BTN_TRIGGER 0x120
#define BTN_THUMB 0x121
#define BTN_THUMB2 0x122
#define BTN_TOP 0x123
#define BTN_TOP2 0x124
#define BTN_PINKIE 0x125
#define BTN_BASE 0x126
#define BTN_BASE2 0x127
#define BTN_BASE3 0x128
#define BTN_BASE4 0x129
#define BTN_BASE5 0x12a
#define BTN_BASE6 0x12b
#define BTN_DEAD 0x12f
#define BTN_GAMEPAD 0x130
#define BTN_SOUTH 0x130
#define BTN_A BTN_SOUTH
#define BTN_EAST 0x131
#define BTN_B BTN_EAST
#define BTN_C 0x132
#define BTN_NORTH 0x133
#define BTN_X BTN_NORTH
#define BTN_WEST 0x134
#define BTN_Y BTN_WEST
#define BTN_Z 0x135
#define BTN_TL 0x136
#define BTN_TR 0x137
#define BTN_TL2 0x138
#define BTN_TR2 0x139
#define BTN_SELECT 0x13a
#define BTN_START 0x13b
#define BTN_MODE 0x13c
#define BTN_THUMBL 0x13d
#define BTN_THUMBR 0x13e
#define BTN_DIGI 0x140
#define BTN_TOOL_PEN 0x140
#define BTN_TOOL_RUBBER 0x141
#define BTN_TOOL_BRUSH 0x142
#define BTN_TOOL_PENCIL 0x143
#define BTN_TOOL_AIRBRUSH 0x144
#define BTN_TOOL_FINGER 0x145
#define BTN_TOOL_MOUSE 0x146
#define BTN_TOOL_LENS 0x147
#define BTN_TOOL_QUINTTAP 0x148 /* Five fingers on trackpad */
#define BTN_STYLUS3 0x149
#define BTN_TOUCH 0x14a
#define BTN_STYLUS 0x14b
#define BTN_STYLUS2 0x14c
#define BTN_TOOL_DOUBLETAP 0x14d
#define BTN_TOOL_TRIPLETAP 0x14e
#define BTN_TOOL_QUADTAP 0x14f /* Four fingers on trackpad */
#define BTN_WHEEL 0x150
#define BTN_GEAR_DOWN 0x150
#define BTN_GEAR_UP 0x151

复制代码

根据上面的定义，我们更新下DTS文件，修改键值定义为BTN_1

源码目录下输入make dtbs 编译DTB文件，发现会更新如下dtb 文件，我们更新6252的至我们的开发板

更新开发板后再次运行之前的event函数，查看下按键的键值是否按照预期的发生改变，运行结果如下：

更新后发现event 的code 值已经按照预期的由BTN_0(0x100)更新为BTN_1(0x101)

[评测分享] 【米尔 MYD-YM62X 开发板入门评测】 4.KEY按键学习

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