【AT-START-F405测评】B1.主题帖：基于USB HID的触摸屏设计
### 功能简介[*]基于USB HID协议，制作触摸屏驱动板
[*]触摸芯片为FT5406，支持最多5点触摸
### 开发简介
1. 创建 workbench 工程
基于VSCODE和EIDE在linux等跨平台上开发的操作详见上一篇帖子：
【AT-START-F405测评】A1.workbench + ATIDE / 纯VSOCDE+EIDE 开发环境搭建 点灯
- 在上一篇的帖子的基础上增加 USB 驱动、ACC 驱动、IIC驱动、USART驱动
- 其中IIC驱动需要将引脚重映射
2. 按照上一篇帖子的方法，倒入工程到EIDE环境中。
- 加入工程所需的库文件、USB驱动库、开发板驱动文件
- 加入EIDE倒入时缺失的.s文件
3. I2C驱动介绍
- FT5406的IIC 7位地址为0x38
- 由于SDK库是使用8位地址操作，并且无需考虑读写位，在底层会自动值位
- 初始化 FT5406 ：对0地址写0
int32_t FT5406_Init(i2c_handle_type *hi2cx)
{
uint8_t tx_buf = {0x0, 0x0};
i2c_status_type i2c_status;
if ((i2c_status = i2c_master_transmit(hi2cx, (FT5406_I2C_ADDR << 1), tx_buf, 2, 0xFFFFFFF)) != I2C_OK)
{
printf("err send\n");
}
return 0;
}
- 读取触摸信息
int32_t FT5406_GetSingleTouch(i2c_handle_type *hi2cx, int *touch_count, touch_point_t touch_array)
{
int32_t ret = 1;
uint8_t touch_buf = {0};
uint8_t tx_buf = {0x1, 0x20};
i2c_status_type i2c_status;
if ((i2c_status = i2c_master_transmit(hi2cx, (FT5406_I2C_ADDR << 1), tx_buf, 1, 0xFFFFFFF)) != I2C_OK)
{
ret = 0;
printf("err send\n");
}
if ((i2c_status = i2c_master_receive(hi2cx, FT5406_I2C_ADDR << 1, touch_buf, FT5406_TOUCH_DATA_LEN, 0xFFFFFFF)) != I2C_OK)
{
ret = 0;
printf("err read\n");
}
if (ret == 1)
{
ft5406_touch_data_t *touch_data = (ft5406_touch_data_t *)(void *)(touch_buf);
int i;
/* Decode number of touches */
if (touch_count)
{
*touch_count = touch_data->TD_STATUS < 5 ? touch_data->TD_STATUS : 0;
}
/* Decode valid touch points */
for (i = 0; i < *touch_count; i++)
{
touch_array.TOUCH_ID = TOUCH_POINT_GET_ID(touch_data->TOUCH);
touch_array.TOUCH_EVENT = TOUCH_POINT_GET_EVENT(touch_data->TOUCH);
touch_array.TOUCH_X = TOUCH_POINT_GET_X(touch_data->TOUCH);
touch_array.TOUCH_Y = TOUCH_POINT_GET_Y(touch_data->TOUCH);
}
/* Clear vacant elements of touch_array */
for (; i < FT5406_MAX_TOUCHES; i++)
{
touch_array.TOUCH_ID = 0;
touch_array.TOUCH_EVENT = kTouch_Reserved;
touch_array.TOUCH_X = 0;
touch_array.TOUCH_Y = 0;
}
}
return 0;
}
4. USB HID驱动介绍
[*] 由于FT5406支持最多5点触摸，因此HID协议的报告描述符也设置为5点。
[*] 基于例程库里面的 CUSTOM HID 例程，创建一个 hid_print 驱动文件
[*] 加入如下的 设备描述符、设备配置符、报告描述符
[*] 设备描述符
ALIGNED_HEAD static uint8_t g_usbd_descriptor ALIGNED_TAIL =
{
USB_DEVICE_DESC_LEN, /* bLength */
USB_DESCIPTOR_TYPE_DEVICE, /* bDescriptorType */
0x10, /* bcdUSB */
0x01,
0x00, /* bDeviceClass */
0x00, /* bDeviceSubClass */
0x00, /* bDeviceProtocol */
USB_MAX_EP0_SIZE, /* bMaxPacketSize */
LBYTE(USBD_CUSHID_VENDOR_ID), /* idVendor */
HBYTE(USBD_CUSHID_VENDOR_ID), /* idVendor */
LBYTE(USBD_CUSHID_PRODUCT_ID), /* idProduct */
HBYTE(USBD_CUSHID_PRODUCT_ID), /* idProduct */
0x00, /* bcdDevice rel. 2.00 */
0x00,
USB_MFC_STRING, /* Index of manufacturer string */
USB_PRODUCT_STRING, /* Index of product string */
USB_LANGID_STRING, /* Index of serial number string */
1 /* bNumConfigurations */
};
[*]设备配置符
ALIGNED_HEAD static uint8_t g_usbd_configuration ALIGNED_TAIL =
{
// 配置描述符
USB_DEVICE_CFG_DESC_LEN, /* bLength: configuration descriptor size */
USB_DESCIPTOR_TYPE_CONFIGURATION, /* bDescriptorType: configuration */
LBYTE(USBD_CUSHID_CONFIG_DESC_SIZE), /* wTotalLength: bytes returned */
HBYTE(USBD_CUSHID_CONFIG_DESC_SIZE), /* wTotalLength: bytes returned */
0x01, /* bNumInterfaces: 1 interface */
0x01, /* bConfigurationValue: configuration value */
0x00, /* iConfiguration: index of string descriptor describing
the configuration */
0xA0, /* bmAttributes: self powered and support remote wakeup */
0x32, /* MaxPower 100 mA: this current is used for detecting vbus */
// 接口描述符
USB_DEVICE_IF_DESC_LEN, /* bLength: interface descriptor size */
USB_DESCIPTOR_TYPE_INTERFACE, /* bDescriptorType: interface descriptor type */
0x00, /* bInterfaceNumber: number of interface */
0x00, /* bAlternateSetting: alternate set */
0x01, /* bNumEndpoints: number of endpoints */
USB_CLASS_CODE_HID, /* bInterfaceClass: class code hid */
0x00, /* bInterfaceSubClass: subclass code */
0x00, /* bInterfaceProtocol: protocol code */
0x00, /* iInterface: index of string descriptor */
// HID类描述符
0x09, /* bLength: size of HID descriptor in bytes */
HID_CLASS_DESC_HID, /* bDescriptorType: HID descriptor type */
LBYTE(CUSHID_BCD_NUM),
HBYTE(CUSHID_BCD_NUM), /* bcdHID: HID class specification release number */
0x00, /* bCountryCode: hardware target conutry */
0x01, /* bNumDescriptors: number of HID class descriptor to follow */
HID_CLASS_DESC_REPORT, /* bDescriptorType: report descriptor type */
0x86, 0x01, /* wDescriptorLength: total length of reprot descriptor */
// 端点描述符
0x07, 0x05, 0x81, 0x03, THIS_ENDP0_SIZE, 0x00, 0x0A,//端点描述符
};
[*]报告描述符（过长，这里省略，详见代码）
ALIGNED_HEAD uint8_t g_usbd_custom_hid_report ALIGNED_TAIL =...
[*]将读取到的FT5406数据转化为 HID 协议
hidFlagLast = hidFlagNow;
hidFlagNow = 0;
for (size_t i = 0; i < 5; i++)
{
hidOneReport = &hidReport.w;
hidOneReport->id = i;
hidOneReport->isPressed = (touch_array.TOUCH_EVENT == kTouch_Down) || (touch_array.TOUCH_EVENT == kTouch_Contact);
if (hidOneReport->isPressed)
{
hidOneReport->x = touch_array.TOUCH_X;
hidOneReport->y = touch_array.TOUCH_Y;
hidOneReport->w = 30;
hidFlagNow++;
}
printf("%x,%x,%x,%x,%x\t", i, touch_array.TOUCH_EVENT,
touch_array.TOUCH_ID, touch_array.TOUCH_X, touch_array.TOUCH_Y);
}
printf("\n");
hidReport.num = hidFlagNow;
5. 驱动演示
- 目前仅能在linux系统下驱动成功，可能是windows下需要打驱动和配置特殊的 product id 到设备描述符。
- 演示：
- 代码：mcu_at32f405_hid_touch_screen
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