Adjust Arduino 101 Bluetooth Package Interval

Official Hardware Retired 101
1

Hello!

I am trying to send a file from Arduino 101 to the Android phone via Bluetooth. But I notice that the package interval is around 100 ms when I enable the BLE notification while transfering the data.

Later, I tried to check the ble_client.h library to adjust the default interval parameters as below:

#define DEFAULT_MIN_CONN_INTERVAL MSEC_TO_UNITS(12, UNIT_1_25_MS)
#define DEFAULT_MAX_CONN_INTERVAL MSEC_TO_UNITS(15, UNIT_1_25_MS)

#define MIN_CONN_INTERVAL 0x0006
#define MAX_CONN_INTERVAL 0x0015

I did receive lower interval for BLE broadcasting, but when I start to transmit the data (with BLE notification enabled), it increases to 98ms. Does anyone have any idea about it?

Thanks in advance!

2

For those who comes later, after you adjust the min, max interval. you will need to adjust the resolution accordingly. Please refer the code below. And the current shortest interval I could retrieve is 30ms, whick could lead to around 666 Bytes/second.

enum {
UNIT_0_200_MS = 200, /< Number of microseconds in 0.200 milliseconds. */
UNIT_0_625_MS = 625, /< Number of microseconds in 0.625 milliseconds. */
UNIT_1_MS = 1000, /< Number of microseconds in 1 milliseconds. */
UNIT_1_25_MS = 1250, /< Number of microseconds in 1.25 milliseconds. */
UNIT_10_MS = 10000 /**< Number of microseconds in 10 milliseconds. */
};

#define MSEC_TO_UNITS(TIME, RESOLUTION) (((TIME) * 1000) / (RESOLUTION))

/* Connection parameters used for Peripheral Preferred Connection Parameterss (PPCP) and update request */
#define DEFAULT_MIN_CONN_INTERVAL MSEC_TO_UNITS(5, UNIT_0_625_MS)
#define DEFAULT_MAX_CONN_INTERVAL MSEC_TO_UNITS(10, UNIT_0_625_MS)

#define MIN_CONN_INTERVAL 0x0005
#define MAX_CONN_INTERVAL 0x000a