User's Manual

HF-BL100-CU Low Energy Bluetooh（BLE 4.0）Module User Manual
Shanghai High Flying Electronics Technology Co., Ltd www.hi-flying.com - 20
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Table 8 Module connect interval 20ms communication mode example
Remark： user can set particular communication mode according to actual application, packet
length can be set between 80byte < L < 200byte ，the relationship as below as per BLE
protocol:
If L<80 ，TS >= T ；
If 80<L<160 ，TS >= T*2 ；
If 160<L<200 ，TS >= T*3 ；
All transmit mode is safe as long as meet above conditions, TS=T is recommended,
TS=T*2，TS=T*3 is ok but the packet lost ratio is high, must add verification and re-transmit
mechanism. In another words, if apply 80byte < L < 200byte ,serial data can transmit to module
in one time, but need to reserve time for sending data from module to Bluetooth, or there will
occur rear-end. E.g. Set connect interval T=20ms, if data length is L=200, TS must over T*3 =
60ms , TS=70ms is a reasonable choice.
Serial data length can be any value under 200 byte. In order to achieve the best efficiency
and avoid full load operation , it is recommended to use 20,40,60 byte serial data packet, set
packet interval over 20ms.
Remark：in IOS, the function used to call Characteristic is:
BCharacteristicWriteWithRespons
e parameter, “write with response” mode would lower transmit efficiency to ensure the
accuracy of each packet, use “ CBCharacteristicWriteWithoutResponse” ; “write without
response” mode would promote transmit efficiency , but the accuracy of packet need to be
verified by APP up level.