I am reading through the RN4870 user guide documentation to try and work out how to implement a HID GATT Service.
When I look at GATT specification viewer for the HID service, specifically at the "Report" characteristic, it appears to me I need another Characteristic Descriptor that is not the Client Characteristic Configuration Descriptor (CCCD). I need a "Report Reference Descriptor" as well. However, the CCCD cannot be created in the RN4870. According to this document:
If we take a close look at the Heart Rate Measurement characteristic, we notice that it includes a Descriptor. That descriptor is the Client Characteristic Configuration Descriptor (CCCD). From our results of the LS command, we see that we have four lines of characteristics; one of those four, specifically the second one, is the CCCD which was added by the RN4870 automatically.
So it seems that the CCCD is added by the RN4870 automatically whenever you indicate that your Characteristic will need to be Indicated or Notified over GATT.
However, I need no commands in the manual to declare any other custom Characteristic Descriptors. And, without that, I fail to see how I can create a HID over GATT service using the RN4870 module.
My questions are:
- Is there any way to implement a "Report Reference Descriptor" defined in the HIDS spec with an RN4870?
- If not, is there any other Bluetooth module provided by Microchip which does allow that?
Cheers and thanks in advance for your time!