This is the quick start guide for the USB Device Keyboard Module (UDI Keyboard) with step-by-step instructions on how to configure and use the modules in a selection of use cases.

The use cases contain several code fragments. The code fragments in the steps for setup can be copied into a custom initialization function, while the steps for usage can be copied into, e.g., the main application function.

Basic Use Case

In this basic use case, the "USB HID keyboard (Single Interface Device)" module is used. The "USB HID keyboard (Composite Device)" module usage is described in Advanced Use Cases.

Setup Steps

As a USB device, it follows common USB device setup steps. Refer to USB Device Basic Setup.

Usage Steps

Example Code

Content of conf_usb.h:

#define UDI_HID_KBD_ENABLE_EXT() my_callback_keyboard_enable()
extern bool my_callback_keyboard_enable(void);
#define UDI_HID_KBD_DISABLE_EXT() my_callback_keyboard_disable()
extern void my_callback_keyboard_disable(void);
#include "udi_hid_keyboard_conf.h" // At the end of conf_usb.h file

Add to application C-file:

static bool my_flag_autorize_keyboard_events = false;
bool my_callback_keyboard_enable(void)
{
   my_flag_autorize_keyboard_events = true;
   return true;
}
void my_callback_keyboard_disable(void)
{
   my_flag_autorize_keyboard_events = false;
}
void my_key_A_press_event(void)
{
   if (!my_flag_autorize_keyboard_events) {
      return;
   }
   udi_hid_kbd_up(HID_A);
}

Workflow

Ensure that conf_usb.h is available and contains the following configuration which is the USB device keyboard configuration:
#define UDI_HID_KBD_ENABLE_EXT() my_callback_keyboard_enable()

extern bool my_callback_keyboard_enable(void);

Note
After the device enumeration (detecting and identifying USB devices), the USB host starts the device configuration. When the USB keyboard interface from the device is accepted by the host, the USB host enables this interface and the UDI_HID_KBD_ENABLE_EXT() callback function is called and return true. Thus, it is recommended to enable sensors used by the keyboard in this function.

#define UDI_HID_KBD_DISABLE_EXT() my_callback_keyboard_disable()

extern void my_callback_keyboard_disable(void);

Note
When the USB device is unplugged or is reset by the USB host, the USB interface is disabled and the UDI_HID_KBD_DISABLE_EXT() callback function is called. Thus, it is recommended to disable sensors used by the keyboard in this function.
Send keyboard events:
// Send events key modifier released

udi_hid_kbd_modifier_up(uint8_t modifier_id);

// Send events key modifier pressed

udi_hid_kbd_modifier_down(uint8_t modifier_id);

// Send events key released

udi_hid_kbd_up(uint8_t key_id);

// Send events key pressed

udi_hid_kbd_down(uint8_t key_id);

Advanced Use Cases

For more advanced use of the UHI HID keyboard module, see the following use cases: