How to create a nRF8001 configuration for touch device with nRFgo

[Quark]

According to Microsoft's instruction on HID touch device, msdn.microsoft.com/.../dn672271(v=vs.85).aspx, a HID touch device should create a report (descriptor) as below,

0x05, 0x0d,                         // USAGE_PAGE (Digitizers)          
0x09, 0x04,                         // USAGE (Touch Screen)             
0xa1, 0x01,                         // COLLECTION (Application)         
0x85, 0x01,                        //   REPORT_ID (Touch)              
0x09, 0x22,                         //   USAGE (Finger)                 
0xa1, 0x02,                         //     COLLECTION (Logical)  
0x09, 0x42,                         //       USAGE (Tip Switch)           
0x15, 0x00,                         //       LOGICAL_MINIMUM (0)          
0x25, 0x01,                         //       LOGICAL_MAXIMUM (1)          
0x75, 0x01,                         //       REPORT_SIZE (1)              
0x95, 0x01,                         //       REPORT_COUNT (1)             
0x81, 0x02,                         //       INPUT (Data,Var,Abs) 
0x95, 0x07,                         //       REPORT_COUNT (7)  
0x81, 0x03,                         //       INPUT (Cnst,Ary,Abs)
0x75, 0x08,                         //       REPORT_SIZE (8)
0x09, 0x51,                         //       USAGE (Contact Identifier)
0x95, 0x01,                         //       REPORT_COUNT (1)             
0x81, 0x02,                         //       INPUT (Data,Var,Abs) 
0x05, 0x01,                         //       USAGE_PAGE (Generic Desk..
0x26, 0xff, 0x0f,                   //       LOGICAL_MAXIMUM (4095)         
0x75, 0x10,                         //       REPORT_SIZE (16)             
0x55, 0x0e,                         //       UNIT_EXPONENT (-2)           
0x65, 0x13,                         //       UNIT(Inch,EngLinear)                  
0x09, 0x30,                         //       USAGE (X)                    
0x35, 0x00,                         //       PHYSICAL_MINIMUM (0)         
0x46, 0xb5, 0x04,                   //       PHYSICAL_MAXIMUM (1205)
0x95, 0x02,                         //       REPORT_COUNT (2)         
0x81, 0x02,                         //       INPUT (Data,Var,Abs)         
0x46, 0x8a, 0x03,                   //       PHYSICAL_MAXIMUM (906)
0x09, 0x31,                         //       USAGE (Y)                    
0x81, 0x02,                         //       INPUT (Data,Var,Abs)
0x05, 0x0d,                         //       USAGE_PAGE (Digitizers)
0x09, 0x48,                         //       USAGE (Width)                
0x09, 0x49,                         //       USAGE (Height)               
0x81, 0x02,                         //       INPUT (Data,Var,Abs)
0x95, 0x01,                         //       REPORT_COUNT (1)
0x55, 0x0C,                         //       UNIT_EXPONENT (-4)           
0x65, 0x12,                         //       UNIT (Radians,SIROtation)        
0x35, 0x00,                         //       PHYSICAL_MINIMUM (0)         
0x47, 0x6f, 0xf5, 0x00, 0x00,        //      PHYSICAL_MAXIMUM (62831)      
0x15, 0x00,                         //       LOGICAL_MINIMUM (0)      
0x27, 0x6f, 0xf5, 0x00, 0x00,       //       LOGICAL_MAXIMUM (62831)        
0x09, 0x3f,                         //       USAGE (Azimuth[Orientation]) 
0x81, 0x02,                         //       INPUT (Data,Var,Abs)  
0xc0,                               //    END_COLLECTION
0x09, 0x22,                         //   USAGE (Finger)                 
0xa1, 0x02,                         //     COLLECTION (Logical)  
0x09, 0x42,                         //       USAGE (Tip Switch)           
0x15, 0x00,                         //       LOGICAL_MINIMUM (0)          
0x25, 0x01,                         //       LOGICAL_MAXIMUM (1)          
0x75, 0x01,                         //       REPORT_SIZE (1)              
0x95, 0x01,                         //       REPORT_COUNT (1)             
0x81, 0x02,                         //       INPUT (Data,Var,Abs) 
0x95, 0x07,                         //       REPORT_COUNT (7)  
0x81, 0x03,                         //       INPUT (Cnst,Ary,Abs)
0x75, 0x08,                         //       REPORT_SIZE (8)
0x09, 0x51,                         //       USAGE (Contact Identifier)
0x95, 0x01,                         //       REPORT_COUNT (1)             
0x81, 0x02,                         //       INPUT (Data,Var,Abs) 
0x05, 0x01,                         //       USAGE_PAGE (Generic Desk..
0x26, 0xff, 0x0f,                   //       LOGICAL_MAXIMUM (4095)         
0x75, 0x10,                         //       REPORT_SIZE (16)             
0x55, 0x0e,                         //       UNIT_EXPONENT (-2)           
0x65, 0x13,                         //       UNIT(Inch,EngLinear)                  
0x09, 0x30,                         //       USAGE (X)                    
0x35, 0x00,                         //       PHYSICAL_MINIMUM (0)         
0x46, 0xb5, 0x04,                   //       PHYSICAL_MAXIMUM (1205)
0x95, 0x02,                         //       REPORT_COUNT (2)         
0x81, 0x02,                         //       INPUT (Data,Var,Abs)         
0x46, 0x8a, 0x03,                   //       PHYSICAL_MAXIMUM (906)
0x09, 0x31,                         //       USAGE (Y)                    
0x81, 0x02,                         //       INPUT (Data,Var,Abs)
0x05, 0x0d,                         //       USAGE_PAGE (Digitizers)
0x09, 0x48,                         //       USAGE (Width)                
0x09, 0x49,                         //       USAGE (Height)               
0x81, 0x02,                         //       INPUT (Data,Var,Abs)
0x95, 0x01,                         //       REPORT_COUNT (1)
0x55, 0x0C,                         //       UNIT_EXPONENT (-4)           
0x65, 0x12,                         //       UNIT (Radians,SIROtation)        
0x35, 0x00,                         //       PHYSICAL_MINIMUM (0)         
0x47, 0x6f, 0xf5, 0x00, 0x00,        //      PHYSICAL_MAXIMUM (62831)      
0x15, 0x00,                         //       LOGICAL_MINIMUM (0)      
0x27, 0x6f, 0xf5, 0x00, 0x00,       //       LOGICAL_MAXIMUM (62831)        
0x09, 0x3f,                         //       USAGE (Azimuth[Orientation]) 
0x81, 0x02,                         //       INPUT (Data,Var,Abs)  
0xc0,                               //    END_COLLECTION
0x05, 0x0d,                         //    USAGE_PAGE (Digitizers)
0x55, 0x0C,                         //     UNIT_EXPONENT (-4)           
0x66, 0x01, 0x10,                   //     UNIT (Seconds)        
0x47, 0xff, 0xff, 0x00, 0x00,      //       PHYSICAL_MAXIMUM (65535)
0x27, 0xff, 0xff, 0x00, 0x00,         //   LOGICAL_MAXIMUM (65535) 
0x75, 0x10,                           //   REPORT_SIZE (16)             
0x95, 0x01,                           //   REPORT_COUNT (1) 
0x09, 0x56,                         //   USAGE (Scan Time)    
0x81, 0x02,                           //   INPUT (Data,Var,Abs)         
0x09, 0x54,                         //   USAGE (Contact count)
0x25, 0x7f,                           //   LOGICAL_MAXIMUM (127) 
0x95, 0x01,                         //   REPORT_COUNT (1)
0x75, 0x08,                         //   REPORT_SIZE (8)    
0x81, 0x02,                         //   INPUT (Data,Var,Abs)
0x85, REPORTID_MAX_COUNT,            //   REPORT_ID (Feature)              
0x09, 0x55,                         //   USAGE(Contact Count Maximum)
0x95, 0x01,                         //   REPORT_COUNT (1)
0x25, 0x02,                         //   LOGICAL_MAXIMUM (2)
0xb1, 0x02,                         //   FEATURE (Data,Var,Abs)
0x85, 0x44,                      //   REPORT_ID (Feature)
0x06, 0x00, 0xff,                   //   USAGE_PAGE (Vendor Defined)  
0x09, 0xC5,                         //   USAGE (Vendor Usage 0xC5)    
0x15, 0x00,                         //   LOGICAL_MINIMUM (0)          
0x26, 0xff, 0x00,                   //   LOGICAL_MAXIMUM (0xff) 
0x75, 0x08,                         //   REPORT_SIZE (8)             
0x96, 0x00,  0x01,                  //   REPORT_COUNT (0x100 (256))             
0xb1, 0x02,                         //   FEATURE (Data,Var,Abs) 
0xc0,                               // END_COLLECTIONÂ  Â Â 

How can I create a nRF8001 configuration with nRFgo which meets the above requirements? I tried days but still could not get it right. Please help! Thanks!

[Hung Bui]

Hi Quark,

Have you had a look at the nRF8001 SDK for Arduino? You can find this tutorial video here explaining how to do HID report with nRFGo Studio: https://github.com/NordicSemiconductor/ble-sdk-arduino/tree/master/documentation/libraries/BLE/examples/ble_HID_template

[Quark]

Hi, Hung,

I have read nRF8001 SDK for Arduino and read all the documents, but it did not tell enough information of how to create a different configuration other than the examples. For example, I have no idea how the initial Value, 05010906A101050719e029e715002501750195088102950175088101950575010508190129059102950175039101950675081500256505071900296581000905150026FF0075089502B102C0, in Report Descriptor of HID_Keyboard_template comes from? Or in another word, how to create configuration according to the descriptor? I guess the Initial value in the Report Descriptor is the same stuff as I listed in the question which is required by Windows Digitizer, so should this value be created manually and added into the Report Map? If so, how do I create a HID service matching the descriptor? There are a lot of Usage Pages/Usages, and Report Values. I think a guide of Usage Pages/Usages/Report Value to configuration mapping table would be helpful. Thank you!

[Hung Bui]

Have you watched the .mp4 video ? It shows you how to create that configuration code from the descriptor. Simply remove the 0x hex prefix and put them together.

[Quark]

Hi, Hung, thank you for following up. Yes, I did and I did create the descriptor by removing 0x and kept only the hex, but I do not know how to create corresponding characteristics in nRFgo to match the report descriptor and I cannot tell the relationship between nRFgo Report and Descrptor hex.

For example, in hid_keyboard_template, there is a generated file, USB HID Report Descriptor - Keyboard.txt, which interpret the hex code to the Usage Pages/Usage/Report - just like the above descriptor. I can see there are many report in this example, but why and how should the HID_Report field (ACI: PIPE_HID_SERVICE_HID_REPORT_TX) corresponded to them?

[Quark]

Hi, Hung, after read again HID over GATT maps USB HID to the Bluetooth Generic Attribute Profile.doc, I kind of get the idea. The Initial Value in Report Reference is the reference ID to Report ID. In hid_keyboard_template, there is no Report ID field in descriptor, so I kind of confused. But then I learned the Input Report reference ID is 0001 which refers to the only one report in the descriptor. I hope I am understanding this correctly.