Hi,
I have some questions concerning the scan parameters for device discovery.
In fact, in my project there are two devices : a central and a peripheral device. The peripheral device send during 4 seconds advertissements in limited mode after a key press. The central is continiously 'sniffing' for advertissements every 4 seconds with short shot. I search to set the minimal time for a scan shot.
However, if the scan shot time is too short, sometimes it detetect advertissements, sometimes not.
So today, the best configuration I found is (I want shorter time for the central, 1 or 2 ms) :
For the peripheral :
GAP_SetParamValue(TGAP_LIM_DISC_ADV_INT_MIN,32); // 20ms
GAP_SetParamValue(TGAP_LIM_DISC_ADV_INT_MAX,32);
GAPRole_SetParameter( GAPROLE_ADVERT_OFF_TIME, sizeof( uint16 ), 4000 ); //4 seconds
For the central :
GAP_SetParamValue( TGAP_LIM_DISC_SCAN, 60); // 60ms
The scan is called by an OSAL Timer every 4 seconds.
Schema :
A is GAPROLE_ADVERT_OFF_TIME = 4000 (4s)
B is TGAP_LIM_DISC_ADV_INT_X = 32 (20ms)
C is TGAP_LIM_DISC_SCAN = 60 (60ms)
D is the OSAL Timer delay (4s)
Now, some questions :
1) Have I understood the parameters meaning ?
2) What's mean the scan window ?
3) When I a set value lower than 32 for TGAP_LIM_DISC_ADV_INT_X, packets are not sent. Why ?
4) Maybe there are specials parameters for this type of scan ?
I feel lost with the scanning procedure...
Thank a lot for your answers, and sorry for my poor english (it isn't my mother tongue)...
Antoine.
