esp32笔记[16]-usb_host_hid读取键盘
摘要
esp32s3作为usb-host设备读取usb-hid键盘并通过串口打印按键值.
关键信息
- 编译环境:ESP-IDF v5.2
- board: 酷世DIY ESP32S3开发板 Link:https://item.taobao.com/item.htm?&id=655913924680
原理简介
usb-host与usb-slave区别
[https://www.cnblogs.com/fire909090/p/11451771.html]
[https://blog.csdn.net/xd1103121507/article/details/6941153]
USB是由Host端控制整个总线的数据传输的。单个USB总线上，只能有一个Host。
host就是主的，可以起控制作用；device(slave)就是从，是被控制的。比如PC机的USB口，可以识别U盘或者其他USB设备，起到控制的作用，就是host;而U盘是被控制的，是device(slave)。
只有一个host和一个device(slave)才能起到数据传输或者控制的作用。
OTG (On The Go)，这是在USB2.0引入的一种mode，提出了一个新的概念叫主机协商协议（Host Negotiation Protocol），允许两个设备间商量谁去当Host。
usb-hid简介
[http://www.baiheee.com/Documents/090522/090522165226.htm]
[http://www.baiheee.com/Documents/090518/090518112619.htm]
[https://www.cnblogs.com/AlwaysOnLines/p/3843186.html]
USB HID类是比较大的一个类，HID类设备属于人机交互操作的设备。用于控制计算机操作的一些方面，如USB鼠标，USB键盘，USB游戏操纵杆，USB触摸板，USB轨迹球、电话拨号设备、VCR遥控等等设备。另外，使用HID设备的一个好处就是，操作系统自带了HID类的驱动程序，而用户无需去开发很麻烦的驱动程序，只要直接使用API调用即可完成通信。所以很多简单的USB设备，喜欢枚举成HID设备，这样就可以不用安装驱动而直接使用。
所有的HID设备通过USB的控制管道（默认管道，即端点0）和中断管道与主机通信。
HID设备的描述符除了5个USB的标准描述符（设备描述符、配置描述符、接口描述符、端点描述符、字符串描述符外，还包括3个HID设备类特定描述符：HID描述符、报告描述符、实体描述符。
实现
核心代码
- 复制例程
docker pull espressif/idf:release-v5.2
docker run --rm -v $PWD:/project -w /project -it espressif/idf:release-v5.2 bash -c "cp -r /opt/esp/idf/examples/peripherals/usb/host/hid /project"
- 代码
.
├── CMakeLists.txt
├── README.md
├── dependencies.lock
├── main
│ ├── CMakeLists.txt
│ ├── hid_host_example.c
│ └── idf_component.yml
├── managed_components
│ └── espressif__usb_host_hid
│ ├── CHANGELOG.md
│ ├── CMakeLists.txt
│ ├── LICENSE
│ ├── README.md
│ ├── hid_host.c
│ ├── idf_component.yml
│ ├── include
│ │ └── usb
│ │ ├── hid.h
│ │ ├── hid_host.h
│ │ ├── hid_usage_keyboard.h
│ │ └── hid_usage_mouse.h
│ └── test
│ ├── CMakeLists.txt
│ ├── hid_mock_device.c
│ ├── hid_mock_device.h
│ ├── test_hid_basic.c
│ ├── test_hid_basic.h
│ └── test_hid_err_handling.c
└── sdkconfig
7 directories, 23 files
main/hid_host_example.c
/*
* SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "freertos/queue.h"
#include "esp_err.h"
#include "esp_log.h"
#include "usb/usb_host.h"
#include "errno.h"
#include "driver/gpio.h"
#include "usb/hid_host.h"
#include "usb/hid_usage_keyboard.h"
#include "usb/hid_usage_mouse.h"
/* GPIO Pin number for quit from example logic */
#define APP_QUIT_PIN GPIO_NUM_0
static const char *TAG = "example";
QueueHandle_t app_event_queue = NULL;
/**
* @brief APP event group
*
* Application logic can be different. There is a one among other ways to distingiush the
* event by application event group.
* In this example we have two event groups:
* APP_EVENT - General event, which is APP_QUIT_PIN press event (Generally, it is IO0).
* APP_EVENT_HID_HOST - HID Host Driver event, such as device connection/disconnection or input report.
*/
typedef enum {
APP_EVENT = 0,
APP_EVENT_HID_HOST
} app_event_group_t;
/**
* @brief APP event queue
*
* This event is used for delivering the HID Host event from callback to a task.
*/
typedef struct {
app_event_group_t event_group;
/* HID Host - Device related info */
struct {
hid_host_device_handle_t handle;
hid_host_driver_event_t event;
void *arg;
} hid_host_device;
} app_event_queue_t;
/**
* @brief HID Protocol string names
*/
static const char *hid_proto_name_str[] = {
"NONE",
"KEYBOARD",
"MOUSE"
};
/**
* @brief Key event
*/
typedef struct {
enum key_state {
KEY_STATE_PRESSED = 0x00,
KEY_STATE_RELEASED = 0x01
} state;
uint8_t modifier;
uint8_t key_code;
} key_event_t;
/* Main char symbol for ENTER key */
#define KEYBOARD_ENTER_MAIN_CHAR '\r'
/* When set to 1 pressing ENTER will be extending with LineFeed during serial debug output */
#define KEYBOARD_ENTER_LF_EXTEND 1
/**
* @brief Scancode to ascii table
*/
const uint8_t keycode2ascii [57][2] = {
{0, 0}, /* HID_KEY_NO_PRESS */
{0, 0}, /* HID_KEY_ROLLOVER */
{0, 0}, /* HID_KEY_POST_FAIL */
{0, 0}, /* HID_KEY_ERROR_UNDEFINED */
{'a', 'A'}, /* HID_KEY_A */
{'b', 'B'}, /* HID_KEY_B */
{'c', 'C'}, /* HID_KEY_C */
{'d', 'D'}, /* HID_KEY_D */
{'e', 'E'}, /* HID_KEY_E */
{'f', 'F'}, /* HID_KEY_F */
{'g', 'G'}, /* HID_KEY_G */
{'h', 'H'}, /* HID_KEY_H */
{'i', 'I'}, /* HID_KEY_I */
{'j', 'J'}, /* HID_KEY_J */
{'k', 'K'}, /* HID_KEY_K */
{'l', 'L'}, /* HID_KEY_L */
{'m', 'M'}, /* HID_KEY_M */
{'n', 'N'}, /* HID_KEY_N */
{'o', 'O'}, /* HID_KEY_O */
{'p', 'P'}, /* HID_KEY_P */
{'q', 'Q'}, /* HID_KEY_Q */
{'r', 'R'}, /* HID_KEY_R */
{'s', 'S'}, /* HID_KEY_S */
{'t', 'T'}, /* HID_KEY_T */
{'u', 'U'}, /* HID_KEY_U */
{'v', 'V'}, /* HID_KEY_V */
{'w', 'W'}, /* HID_KEY_W */
{'x', 'X'}, /* HID_KEY_X */
{'y', 'Y'}, /* HID_KEY_Y */
{'z', 'Z'}, /* HID_KEY_Z */
{'1', '!'}, /* HID_KEY_1 */
{'2', '@'}, /* HID_KEY_2 */
{'3', '#'}, /* HID_KEY_3 */
{'4', '$'}, /* HID_KEY_4 */
{'5', '%'}, /* HID_KEY_5 */
{'6', '^'}, /* HID_KEY_6 */
{'7', '&'}, /* HID_KEY_7 */
{'8', '*'}, /* HID_KEY_8 */
{'9', '('}, /* HID_KEY_9 */
{'0', ')'}, /* HID_KEY_0 */
{KEYBOARD_ENTER_MAIN_CHAR, KEYBOARD_ENTER_MAIN_CHAR}, /* HID_KEY_ENTER */
{0, 0}, /* HID_KEY_ESC */
{'\b', 0}, /* HID_KEY_DEL */
{0, 0}, /* HID_KEY_TAB */
{' ', ' '}, /* HID_KEY_SPACE */
{'-', '_'}, /* HID_KEY_MINUS */
{'=', '+'}, /* HID_KEY_EQUAL */
{'[', '{'}, /* HID_KEY_OPEN_BRACKET */
{']', '}'}, /* HID_KEY_CLOSE_BRACKET */
{'\\', '|'}, /* HID_KEY_BACK_SLASH */
{'\\', '|'}, /* HID_KEY_SHARP */ // HOTFIX: for NonUS Keyboards repeat HID_KEY_BACK_SLASH
{';', ':'}, /* HID_KEY_COLON */
{'\'', '"'}, /* HID_KEY_QUOTE */
{'`', '~'}, /* HID_KEY_TILDE */
{',', '<'}, /* HID_KEY_LESS */
{'.', '>'}, /* HID_KEY_GREATER */
{'/', '?'} /* HID_KEY_SLASH */
};
/**
* @brief Makes new line depending on report output protocol type
*
* @param[in] proto Current protocol to output
*/
static void hid_print_new_device_report_header(hid_protocol_t proto)
{
static hid_protocol_t prev_proto_output = -1;
if (prev_proto_output != proto) {
prev_proto_output = proto;
printf("\r\n");
if (proto == HID_PROTOCOL_MOUSE) {
printf("Mouse\r\n");
} else if (proto == HID_PROTOCOL_KEYBOARD) {
printf("Keyboard\r\n");
} else {
printf("Generic\r\n");
}
fflush(stdout);
}
}
/**
* @brief HID Keyboard modifier verification for capitalization application (right or left shift)
*
* @param[in] modifier
* @return true Modifier was pressed (left or right shift)
* @return false Modifier was not pressed (left or right shift)
*
*/
static inline bool hid_keyboard_is_modifier_shift(uint8_t modifier)
{
if (((modifier & HID_LEFT_SHIFT) == HID_LEFT_SHIFT) ||
((modifier & HID_RIGHT_SHIFT) == HID_RIGHT_SHIFT)) {
return true;
}
return false;
}
/**
* @brief HID Keyboard get char symbol from key code
*
* @param[in] modifier Keyboard modifier data
* @param[in] key_code Keyboard key code
* @param[in] key_char Pointer to key char data
*
* @return true Key scancode converted successfully
* @return false Key scancode unknown
*/
static inline bool hid_keyboard_get_char(uint8_t modifier,
uint8_t key_code,
unsigned char *key_char)
{
uint8_t mod = (hid_keyboard_is_modifier_shift(modifier)) ? 1 : 0;
if ((key_code >= HID_KEY_A) && (key_code <= HID_KEY_SLASH)) {
*key_char = keycode2ascii[key_code][mod];
} else {
// All other key pressed
return false;
}
return true;
}
/**
* @brief HID Keyboard print char symbol
*
* @param[in] key_char Keyboard char to stdout
*/
static inline void hid_keyboard_print_char(unsigned int key_char)
{
if (!!key_char) {
putchar(key_char);
#if (KEYBOARD_ENTER_LF_EXTEND)
if (KEYBOARD_ENTER_MAIN_CHAR == key_char) {
putchar('\n');
}
#endif // KEYBOARD_ENTER_LF_EXTEND
fflush(stdout);
}
}
/**
* @brief Key Event. Key event with the key code, state and modifier.
*
* @param[in] key_event Pointer to Key Event structure
*
*/
static void key_event_callback(key_event_t *key_event)
{
unsigned char key_char;
hid_print_new_device_report_header(HID_PROTOCOL_KEYBOARD);
if (KEY_STATE_PRESSED == key_event->state) {
if (hid_keyboard_get_char(key_event->modifier,
key_event->key_code, &key_char)) {
hid_keyboard_print_char(key_char);
}
}
}
/**
* @brief Key buffer scan code search.
*
* @param[in] src Pointer to source buffer where to search
* @param[in] key Key scancode to search
* @param[in] length Size of the source buffer
*/
static inline bool key_found(const uint8_t *const src,
uint8_t key,
unsigned int length)
{
for (unsigned int i = 0; i < length; i++) {
if (src[i] == key) {
return true;
}
}
return false;
}
/**
* @brief USB HID Host Keyboard Interface report callback handler
*
* @param[in] data Pointer to input report data buffer
* @param[in] length Length of input report data buffer
*/
static void hid_host_keyboard_report_callback(const uint8_t *const data, const int length)
{
hid_keyboard_input_report_boot_t *kb_report = (hid_keyboard_input_report_boot_t *)data;
if (length < sizeof(hid_keyboard_input_report_boot_t)) {
return;
}
static uint8_t prev_keys[HID_KEYBOARD_KEY_MAX] = { 0 };
key_event_t key_event;
for (int i = 0; i < HID_KEYBOARD_KEY_MAX; i++) {
// key has been released verification
if (prev_keys[i] > HID_KEY_ERROR_UNDEFINED &&
!key_found(kb_report->key, prev_keys[i], HID_KEYBOARD_KEY_MAX)) {
key_event.key_code = prev_keys[i];
key_event.modifier = 0;
key_event.state = KEY_STATE_RELEASED;
key_event_callback(&key_event);
}
// key has been pressed verification
if (kb_report->key[i] > HID_KEY_ERROR_UNDEFINED &&
!key_found(prev_keys, kb_report->key[i], HID_KEYBOARD_KEY_MAX)) {
key_event.key_code = kb_report->key[i];
key_event.modifier = kb_report->modifier.val;
key_event.state = KEY_STATE_PRESSED;
key_event_callback(&key_event);
}
}
memcpy(prev_keys, &kb_report->key, HID_KEYBOARD_KEY_MAX);
}
/**
* @brief USB HID Host Mouse Interface report callback handler
*
* @param[in] data Pointer to input report data buffer
* @param[in] length Length of input report data buffer
*/
static void hid_host_mouse_report_callback(const uint8_t *const data, const int length)
{
hid_mouse_input_report_boot_t *mouse_report = (hid_mouse_input_report_boot_t *)data;
if (length < sizeof(hid_mouse_input_report_boot_t)) {
return;
}
static int x_pos = 0;
static int y_pos = 0;
// Calculate absolute position from displacement
x_pos += mouse_report->x_displacement;
y_pos += mouse_report->y_displacement;
hid_print_new_device_report_header(HID_PROTOCOL_MOUSE);
printf("X: %06d\tY: %06d\t|%c|%c|\r",
x_pos, y_pos,
(mouse_report->buttons.button1 ? 'o' : ' '),
(mouse_report->buttons.button2 ? 'o' : ' '));
fflush(stdout);
}
/**
* @brief USB HID Host Generic Interface report callback handler
*
* 'generic' means anything else than mouse or keyboard
*
* @param[in] data Pointer to input report data buffer
* @param[in] length Length of input report data buffer
*/
static void hid_host_generic_report_callback(const uint8_t *const data, const int length)
{
hid_print_new_device_report_header(HID_PROTOCOL_NONE);
for (int i = 0; i < length; i++) {
printf("%02X", data[i]);
}
putchar('\r');
}
/**
* @brief USB HID Host interface callback
*
* @param[in] hid_device_handle HID Device handle
* @param[in] event HID Host interface event
* @param[in] arg Pointer to arguments, does not used
*/
void hid_host_interface_callback(hid_host_device_handle_t hid_device_handle,
const hid_host_interface_event_t event,
void *arg)
{
uint8_t data[64] = { 0 };
size_t data_length = 0;
hid_host_dev_params_t dev_params;
ESP_ERROR_CHECK(hid_host_device_get_params(hid_device_handle, &dev_params));
switch (event) {
case HID_HOST_INTERFACE_EVENT_INPUT_REPORT:
ESP_ERROR_CHECK(hid_host_device_get_raw_input_report_data(hid_device_handle,
data,
64,
&data_length));
if (HID_SUBCLASS_BOOT_INTERFACE == dev_params.sub_class) {
if (HID_PROTOCOL_KEYBOARD == dev_params.proto) {
hid_host_keyboard_report_callback(data, data_length);
} else if (HID_PROTOCOL_MOUSE == dev_params.proto) {
hid_host_mouse_report_callback(data, data_length);
}
} else {
hid_host_generic_report_callback(data, data_length);
}
break;
case HID_HOST_INTERFACE_EVENT_DISCONNECTED:
ESP_LOGI(TAG, "HID Device, protocol '%s' DISCONNECTED",
hid_proto_name_str[dev_params.proto]);
ESP_ERROR_CHECK(hid_host_device_close(hid_device_handle));
break;
case HID_HOST_INTERFACE_EVENT_TRANSFER_ERROR:
ESP_LOGI(TAG, "HID Device, protocol '%s' TRANSFER_ERROR",
hid_proto_name_str[dev_params.proto]);
break;
default:
ESP_LOGE(TAG, "HID Device, protocol '%s' Unhandled event",
hid_proto_name_str[dev_params.proto]);
break;
}
}
/**
* @brief USB HID Host Device event
*
* @param[in] hid_device_handle HID Device handle
* @param[in] event HID Host Device event
* @param[in] arg Pointer to arguments, does not used
*/
void hid_host_device_event(hid_host_device_handle_t hid_device_handle,
const hid_host_driver_event_t event,
void *arg)
{
hid_host_dev_params_t dev_params;
ESP_ERROR_CHECK(hid_host_device_get_params(hid_device_handle, &dev_params));
switch (event) {
case HID_HOST_DRIVER_EVENT_CONNECTED:
ESP_LOGI(TAG, "HID Device, protocol '%s' CONNECTED",
hid_proto_name_str[dev_params.proto]);
const hid_host_device_config_t dev_config = {
.callback = hid_host_interface_callback,
.callback_arg = NULL
};
ESP_ERROR_CHECK(hid_host_device_open(hid_device_handle, &dev_config));
if (HID_SUBCLASS_BOOT_INTERFACE == dev_params.sub_class) {
ESP_ERROR_CHECK(hid_class_request_set_protocol(hid_device_handle, HID_REPORT_PROTOCOL_BOOT));
if (HID_PROTOCOL_KEYBOARD == dev_params.proto) {
ESP_ERROR_CHECK(hid_class_request_set_idle(hid_device_handle, 0, 0));
}
}
ESP_ERROR_CHECK(hid_host_device_start(hid_device_handle));
break;
default:
break;
}
}
/**
* @brief Start USB Host install and handle common USB host library events while app pin not low
*
* @param[in] arg Not used
*/
static void usb_lib_task(void *arg)
{
const usb_host_config_t host_config = {
.skip_phy_setup = false,
.intr_flags = ESP_INTR_FLAG_LEVEL1,
};
ESP_ERROR_CHECK(usb_host_install(&host_config));
xTaskNotifyGive(arg);
while (true) {
uint32_t event_flags;
usb_host_lib_handle_events(portMAX_DELAY, &event_flags);
// In this example, there is only one client registered
// So, once we deregister the client, this call must succeed with ESP_OK
if (event_flags & USB_HOST_LIB_EVENT_FLAGS_NO_CLIENTS) {
ESP_ERROR_CHECK(usb_host_device_free_all());
break;
}
}
ESP_LOGI(TAG, "USB shutdown");
// Clean up USB Host
vTaskDelay(10); // Short delay to allow clients clean-up
ESP_ERROR_CHECK(usb_host_uninstall());
vTaskDelete(NULL);
}
/**
* @brief BOOT button pressed callback
*
* Signal application to exit the HID Host task
*
* @param[in] arg Unused
*/
static void gpio_isr_cb(void *arg)
{
BaseType_t xTaskWoken = pdFALSE;
const app_event_queue_t evt_queue = {
.event_group = APP_EVENT,
};
if (app_event_queue) {
xQueueSendFromISR(app_event_queue, &evt_queue, &xTaskWoken);
}
if (xTaskWoken == pdTRUE) {
portYIELD_FROM_ISR();
}
}
/**
* @brief HID Host Device callback
*
* Puts new HID Device event to the queue
*
* @param[in] hid_device_handle HID Device handle
* @param[in] event HID Device event
* @param[in] arg Not used
*/
void hid_host_device_callback(hid_host_device_handle_t hid_device_handle,
const hid_host_driver_event_t event,
void *arg)
{
const app_event_queue_t evt_queue = {
.event_group = APP_EVENT_HID_HOST,
// HID Host Device related info
.hid_host_device.handle = hid_device_handle,
.hid_host_device.event = event,
.hid_host_device.arg = arg
};
if (app_event_queue) {
xQueueSend(app_event_queue, &evt_queue, 0);
}
}
void app_main(void)
{
BaseType_t task_created;
app_event_queue_t evt_queue;
ESP_LOGI(TAG, "HID Host example");
// Init BOOT button: Pressing the button simulates app request to exit
// It will disconnect the USB device and uninstall the HID driver and USB Host Lib
const gpio_config_t input_pin = {
.pin_bit_mask = BIT64(APP_QUIT_PIN),
.mode = GPIO_MODE_INPUT,
.pull_up_en = GPIO_PULLUP_ENABLE,
.intr_type = GPIO_INTR_NEGEDGE,
};
ESP_ERROR_CHECK(gpio_config(&input_pin));
ESP_ERROR_CHECK(gpio_install_isr_service(ESP_INTR_FLAG_LEVEL1));
ESP_ERROR_CHECK(gpio_isr_handler_add(APP_QUIT_PIN, gpio_isr_cb, NULL));
/*
* Create usb_lib_task to:
* - initialize USB Host library
* - Handle USB Host events while APP pin in in HIGH state
*/
task_created = xTaskCreatePinnedToCore(usb_lib_task,
"usb_events",
4096,
xTaskGetCurrentTaskHandle(),
2, NULL, 0);
assert(task_created == pdTRUE);
// Wait for notification from usb_lib_task to proceed
ulTaskNotifyTake(false, 1000);
/*
* HID host driver configuration
* - create background task for handling low level event inside the HID driver
* - provide the device callback to get new HID Device connection event
*/
const hid_host_driver_config_t hid_host_driver_config = {
.create_background_task = true,
.task_priority = 5,
.stack_size = 4096,
.core_id = 0,
.callback = hid_host_device_callback,
.callback_arg = NULL
};
ESP_ERROR_CHECK(hid_host_install(&hid_host_driver_config));
// Create queue
app_event_queue = xQueueCreate(10, sizeof(app_event_queue_t));
ESP_LOGI(TAG, "Waiting for HID Device to be connected");
while (1) {
// Wait queue
if (xQueueReceive(app_event_queue, &evt_queue, portMAX_DELAY)) {
if (APP_EVENT == evt_queue.event_group) {
// User pressed button
usb_host_lib_info_t lib_info;
ESP_ERROR_CHECK(usb_host_lib_info(&lib_info));
if (lib_info.num_devices == 0) {
// End while cycle
break;
} else {
ESP_LOGW(TAG, "To shutdown example, remove all USB devices and press button again.");
// Keep polling
}
}
if (APP_EVENT_HID_HOST == evt_queue.event_group) {
hid_host_device_event(evt_queue.hid_host_device.handle,
evt_queue.hid_host_device.event,
evt_queue.hid_host_device.arg);
}
}
}
ESP_LOGI(TAG, "HID Driver uninstall");
ESP_ERROR_CHECK(hid_host_uninstall());
gpio_isr_handler_remove(APP_QUIT_PIN);
xQueueReset(app_event_queue);
vQueueDelete(app_event_queue);
}
- 编译&烧录
alias esp-idf='docker run --rm --privileged -v $PWD:/project -w /project -it espressif/idf:release-v5.2 bash -c'
esp-idf "cd /project && idf.py set-target esp32s3"
esp-idf "cd /project && idf.py build"
/opt/homebrew/bin/esptool.py --chip esp32s3 -b 921600 --before default_reset --after hard_reset write_flash --flash_mode dio --flash_size 2MB --flash_freq 80m 0x0 build/bootloader/bootloader.bin 0x8000 build/partition_table/partition-table.bin 0x10000 build/project.bin
效果
键盘输入后需要按下回车键才会在串口打印按键。
| esp32s3连接键盘 | 串口输出 |
|---|---|
 |
 |
