esp-idf/examples/bluetooth/nimble/throughput_app/bleprph_throughput/README.md

Throughput bleprph Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

bleprph_throughput demonstrates server side implementation required for NimBLE throughput example. It has characteristics supporting READ, WRITE and NOTIFY (PTS_LONG_CHR_READ_WRITE,PTS_CHR_READ_WRITE,PTS_CHR_NOTIFY). The data of 500 Bytes (READ_THROUGHPUT_PAYLOAD) and 400 Bytes (WRITE_THROUGHPUT_PAYLOAD) is transferred for throughput GATT read and write operations respectively.

bleprph_throughput uses the nimble component as BLE host.

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

I (573) BTDM_INIT: BT controller compile version [b73c48e]
I (573) system_api: Base MAC address is not set
I (573) system_api: read default base MAC address from EFUSE
I (663) phy: phy_version: 4500, 0cd6843, Sep 17 2020, 15:37:07, 0, 0
I (903) bleprph_throughput: BLE Host Task Started
I (933) bleprph_throughput: Device Address:
I (933) bleprph_throughput: 3c:71:bf:99:38:7a
GAP procedure initiated: advertise; disc_mode=2 adv_channel_map=0 own_addr_type=0 adv_filter_policy=0 adv_itvl_min=0 adv_itvl_max=0
I (1403) bleprph_throughput: connection established; status = 0
I (1433) bleprph_throughput: mtu update event; conn_handle = 0 mtu = 512

In a separate terminal flash and run corresponding blecent_throughput for full fledged throughput demo.

If at the blecent_throughput side notify is selected as GATT operation, then below console output can be observed:

I (23853) bleprph_throughput: subscribe event; cur_notify=1; value handle; val_handle = 14
GATT procedure initiated: notify; att_handle=14
GATT procedure initiated: notify; att_handle=14
GATT procedure initiated: notify; att_handle=14
GATT procedure initiated: notify; att_handle=14
.
.
.

*********************************
I (83943) bleprph_throughput: Notify throughput = 160466 bps, count = 2407

*********************************
I (83943) bleprph_throughput:  Notification test completed for stipulated time of 60 sec

Here, bps is bits per second; count is number of Notifications successfully sent.

Example scope

This demo example along with blecent_throughput tries to demonstrate stable implementation of GATT operations like read/write and notify. For bleprph_throughput app, notifications are sent almost continuously for stipulated period of time. The almost part is because we use counting semaphore (~100) to mimic continuous notifications. Here one needs to understand that notifications are sent in os_mbufs packets and there can always be chance of them getting full because of continuous operation, so one may need to allocate higher number of mbufs through menuconfig, whenever there is os_mbuf memory exhaustion, app provides delay so NimBLE host stack can breathe and free mbuf chains.