is multi touch HID possible with nrf51822 chip?

[akash naidu]

Hi All,

       Currently i am working on nrf51822 for multi touch HID.For that i have chosen mouse HID example as a reference, in which i have changed HID descriptor(single touch) and some other things.So, that single touch has been working.

And, if i changed the HID descriptor for multi touch, touch devices(touch laptop) were showing "Bluetooth driver error".

is it possible multi touch HID over nrf51822 as a reference of mouse HID example?

if possible, what all changes are to be required to work for multi touch.

so, please guide me how to implement multi touch HID over nrf51822.

regards

akash.

[ovrebekk]

Hi Akash

Multi touch should definitely be possible with the nRF51 series. 

Microsoft have some good articles on how to use multi touch with windows, such as this one. Have you had a look at that?

If you still can't make it work, are you able to attach your HID descriptor so I can have a look at it?

Best regards
Torbjørn

[akash naidu]

Thanks for your precious reply.

yes, i have gone through windows multi touch HID, but didn't work for me.

so, i have taken one more multi touch HID, which has been working over USB.

if i emulated same HID into Bluetooth stack, it was not working.

here, i am attaching my HID

0x05, 0x0D, // Usage Page (Digitizer)
0x09, 0x04, // Usage (Touch Screen)
0xA1, 0x01, // Collection (Application)
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,No Wrap,Linear,Preferred State,No Null Position)
0x09, 0x30, // Usage (Tip Pressure)
0x25, 0x7F, // Logical Maximum (127)
0x75, 0x07, // Report Size (7)
0x95, 0x01, // Report Count (1)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x09, 0x51, // Usage (0x51)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x75, 0x08, // Report Size (8)
0x95, 0x01, // Report Count (1)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x01, // Usage Page (Generic Desktop Ctrls)
0x09, 0x30, // Usage (X)
0x09, 0x31, // Usage (Y)
0x26, 0xFF, 0x7F, // Logical Maximum (32767)
0x65, 0x00, // Unit (None)
0x75, 0x10, // Report Size (16)
0x95, 0x02, // Report Count (2)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0xC0, // End Collection
0x05, 0x0D, // Usage Page (Digitizer)
0x27, 0xFF, 0xFF, 0x00, 0x00, // Logical Maximum (65534)
0x75, 0x10, // Report Size (16)
0x95, 0x01, // Report Count (1)
0x09, 0x56, // Usage (0x56)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x09, 0x54, // Usage (0x54)
0x25, 0x05, // Logical Maximum (12)
0x75, 0x08, // Report Size (8)
0x95, 0x01, // Report Count (1)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x0D, // Usage Page (Digitizer)
0x09, 0x55, // Usage (0x55)
0x25, 0x0A, // Logical Maximum (12)
0x75, 0x08, // Report Size (8)
0x95, 0x01, // Report Count (1)
0xB1, 0x02, // Feature (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
0xC0, // End Collection

is there any changes are to be required in code(like feature report, input report,output report)?

because, single touch has been working without adding any feature reports and output reports.

regards,

akash.

[ovrebekk]

Hi 

What are you actually trying to implement? 

This example is quite old and outdated by now, and is not really suitable for new designs. 

These days we have moved development over to the nRF Connect SDK, and at some point it will be mandatory to use this software platform if you want to qualify new Bluetooth products. 

Best regards
Torbjørn

[Leon]

Hi Torbjørn

I am going to make a bluetooth controller. When watching videos with a mobile app, I can control the video to slide up and down (similar to sliding a finger up and down the screen to switch videos).
I can only use the HID mouse example now to achieve this function (similar to the bluetooth mouse to control the video up and down), but for how to position the mouse pointer to the specified position of the phone screen (for example, to the center of the screen), and I found the position of Android phone is different from that of Apple's location.

Attached is my code.8171.main.c

Best regards

Leon

[ovrebekk]

Hi Leon

As far as I know there is no way for a HID mouse to know the screen size of the device that it is connected to, and an implementation that require you to find a specific point of the screen is bound to be unreliable across different types of phones. 

Have you investigated if there is some other way to control the video that doesn't require you to simulate a touch, such as sending a vertical or horisontal scroll command?

Best regards
Torbjørn

[Leon]

Hi Torbjørn

Thanks for the guide, I used two methods to control the video.
1. Use hid devices that simulate touch, but cannot be used on ios and windows.
2. Use the hid device that simulates mouse sliding and left button, but encountered the problems you mentioned.
Now I haven't thought of any other way to do it.

Best regards

Leon

[ovrebekk]

Hi Leon

Have you tried to connect a high end mouse and keyboard that supports Bluetooth to the devices, such as the Logitech MX Master mouse and MX Keys keyboard?

Then you can see if there are any of the standard mouse and keyboard controls that will work across all the platforms, and do what you need it to do. 

Best regards
Torbjørn