nrf51 mouse delay

[bear_xiong]

dear :

 i used sdk 12.3 development  bt mouse.  now i  have a  question.

when one mouse link pc , its mouse x/y axis is ok.

but if two mouse( same code) link pc. oen mouse x/y axis is delay, but other mouse is ok.

and the two mouse x/y axis maybe is 1 is ok, maybe  2 is ok.

but if only use one mouse link pc, it is ok. 

i do not know why?

#define MIN_CONN_INTERVAL MSEC_TO_UNITS(7.5, UNIT_1_25_MS) /**< Minimum connection interval (7.5 ms). */
#define MAX_CONN_INTERVAL MSEC_TO_UNITS(15, UNIT_1_25_MS) /**< Maximum connection interval (15 ms). */
//#define SLAVE_LATENCY 20

i try  SLAVE_LATENCY change to 0  have same problem.

 

[Vidar Berg]

Hello,

Please verify this one more than PC if possible. Also, is this seen on Windows 10, Linux or macOS?

Thanks, 

Vidar

[bear_xiong]

hello.

we test windows 10 . i try   two  logitech mouse in the same pc  .it is ok.

[Vidar Berg]

Hello,

Are both of the Logitech ones communicating over BLE and not Bluetooth classic or through the 'unify' dongle?

[bear_xiong]

hi

logitech and my mouse are both through dongle。。

i find sdk12.3 mouse demo ， every 8ms  call mouse_movement_send()   for x/y. bud pc bushound usb time is not 8ms. it is not delay or fast.

but logitech is every 10ms at hushound.

why?

[Vidar Berg]

Hi,

Can you try to set the MIN_CONN_INTERVAL==MAX_CONN_INTERVAL==7.5ms and see if it helps. It may also be helpful to capture a sniffer trace to compare the two (nRF sniffer).

[bear_xiong]

hi. thanks very much. setting MIN_CONN_INTERVAL==MAX_CONN_INTERVAL ==7.5ms., i see bushound usb time is about 8ms most payloads.

i have some questions:

1. if MIN=MAX =7.5ms. have some problem for different system( andor or mac)?

2.  how many mouses (with same code) can be connected for one pc?  pc or mouse have  astrict?

[Vidar Berg]

Hi,

1. I don't see any problems with requesting this interval range. But keep in mind that GAP central (PC in this case) has the final say when it comes to this so that it may reject your request for 7.5 ms. For instance, the lowest interval you will get with Apple devices is 11.25 ms according to their "Accessory Design Guidelines" document: https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf.  

2. It's not a fixed limit as far as I know. It may depend on the BT chipset, OS, connection interval,.. 

[bear_xiong]

hi

oh. I know. Thanks..