USB Hid Keyboard - When is it ready to transfer?

[AntonHellbe]

Hi everyone,

I'm currently working on an application that uses the USBD HID Keyboard class. However for this particular application I need to know when the USBD is done with the configuration and addressing so that keypresses can be transferred. If I look at the events that passes through the USBD event handler it looks like this (with power detection enabled):

1. USBD Power Detected

2. USBD Ready

3. USBD State Change

4. USBD Started

5. USBD Suspended

6. USBD Resume

7. USBD State change (APP_USBD_STATE_Default)

8. USBD State change (APP_USBD_STATE_Addressed)

9. USBD State change (APP_USBD_STATE_Configured)

The issue is that if I try to send keys immediately after the APP_USBD_STATE_Configured event none of the keys are transfered. Are there any other flags or event handlers that can be useful to detect when the USBD is ready to transmit?

Additional Notes:

I'm SDK V15

[Sigurd]

Hi,

I assume that you are testing the usbd_hid_composite example. 

AntonHellbe said:

Are there any other flags or event handlers that can be useful to detect when the USBD is ready to transmit?

You should be able to send the key after you get the first APP_USBD_HID_USER_EVT_OUT_REPORT_READY event in the hid_kbd_user_ev_handler().

[AntonHellbe]

Hi Sigurd,

Thanks for the answer, we will try it out and see if it works.

Br,
Anton

[Sigurd]

Hi Anton,

Note that if you are using the latest revision of the nRF52840, there are some erratas that has not been properly applied in our SDK;please see this thread.

Br,

Sigurd

[nine-fox]

Hi Sigurd, thanks for your answer. However, the investigation shows that, no APP_USBD_HID_USER_EVT_OUT_REPORT_READY event under MAC OS. While Windows works well, may I ask is there any other way to test?

Thanks,

Vincent