Reg. USB HOST HID Class Keyboard Implementation
Hello,
I have been using STM USB HOST HID class library to implement the USB keyboard on my STM32F429ZI custom board. I have been able to successfully enumerate the USB keyboard and getting the key pressed on the keyboard using the custom keyread() function in blocking mode as per mentioned below:
char keyread()
{
HID_KEYBD_Info_TypeDef *k_pinfo;
char c;
while(1){
MX_USB_HOST_Process();
if(Appli_state == APPLICATION_READY)
{
if(USBH_HID_GetDeviceType(&hUsbHostFS) == HID_KEYBOARD)
{
k_pinfo = USBH_HID_GetKeybdInfo(&hUsbHostFS);
if(k_pinfo != NULL)
{
c = USBH_HID_GetASCIICode(k_pinfo);
if(c != '\0')
return c;
}
}
}
}
return 0;
}
For my application I need to implement the RTC updating GLCD screen and if a key is pressed then it update the screen content with the custom character else it shows the RTC data continously. For this I need to detect the Keyboard key press in between but the above mentioned keyread() is a blocking function so it will not update GLCD screen data with the RTC data and will keep waiting for the key press.
Now for my application I need to implement a function which can identify if a key is pressed or not in non blocking mode. I have tried the above function without while loop but did not get any success.
char ifkeyread()
{
HID_KEYBD_Info_TypeDef *k_pinfo;
char c=0;
//while(1)
{
MX_USB_HOST_Process();
if(Appli_state == APPLICATION_READY)
{
if(USBH_HID_GetDeviceType(&hUsbHostFS) == HID_KEYBOARD)
{
k_pinfo = USBH_HID_GetKeybdInfo(&hUsbHostFS);
if(k_pinfo != NULL)
{
c = USBH_HID_GetASCIICode(k_pinfo);
//if(c != '\0')
// return c;
}
// else
// return 0;
}
// else
// return 0;
}
// else
// return 0;
}
return c;
}
This function is not working. Can anybody suggest me how to determine whether a key is pressed or not in non blocking mode.