如何提高esp_ble_get_cur_sendable_packets_num返回数

[qiuyonggang]

我们使用的芯片是esp32-C3
IDF版本版本：2.8.1
Build id：20230207-1119
我们的产品使用的是BLE Mesh的组网方式，两块板子之间通过通过gatt做ota功能测试的时候，如果板子进行了fast ble mesh prov的初始化，那么ota的过程中esp_ble_get_cur_sendable_packets_num返回的结果中，36次只有3次返回数据1，其他都是返回的数据0，而如果不进行fast ble mesh prov的初始化，那么esp_ble_get_cur_sendable_packets_num返回的结果中，36次只有9次返回的结果是0，其他是1~3的数，这两者的传输速率也是相差了十几倍。
想请教一下，通过什么方式或者配置，能够增加esp_ble_get_cur_sendable_packets_num？

[qiuyonggang]

经过进一步测试发现，esp_ble_get_cur_sendable_packets_num的值在刚开始的时候是一样的，只是进行了fast ble mesh prov的初始化的程序在开始调用了esp_ble_gattc_write_char的方法发送数据后，esp_ble_get_cur_sendable_packets_num恢复的慢，应该就是发送的慢，两者对比的打印日志如下：
进行了fast ble mesh prov的初始化的程序的OTA打印：
I (27839) hyz_gattc.c: [106] gattc_profile_event_handler event 9
I (27849) hyz_gattc.c: [288] write descr success
E (27929) hyz_ble_ota_svr.c: [87] free_buff_num 10
E (27929) hyz_ble_ota_svr.c: [87] free_buff_num 4
E (27939) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27949) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27959) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (27959) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27969) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27979) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27989) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (27999) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28009) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28019) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28029) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28039) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (28039) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28049) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28059) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28069) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28079) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28089) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28099) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28109) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (28119) hyz_ble_ota_svr.c: [87] free_buff_num 1

未进行fast ble mesh prov的初始化的程序的OTA打印：
I (5600) hyz_gattc.c: [288] write descr success
E (5970) hyz_ble_ota_svr.c: [87] free_buff_num 10
E (5970) hyz_ble_ota_svr.c: [87] free_buff_num 4
E (5980) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (5990) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (5990) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (6000) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6000) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6000) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (6010) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6010) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6010) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6020) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6020) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (6040) hyz_ble_ota_svr.c: [87] free_buff_num 2
E (6040) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6040) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (6050) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6050) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6060) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6060) hyz_ble_ota_svr.c: [87] free_buff_num 1
E (6070) hyz_ble_ota_svr.c: [87] free_buff_num 0
E (6080) hyz_ble_ota_svr.c: [87] free_buff_num 2

发送部分代码

send.png (58.38 KiB) Viewed 2700 times

[wmswms]

你好，使用fast mesh prov之后，会占用一定底层的资源，所以空闲buffer的数量会恢复得比较慢。

[lxlxlx]

你好，如wmswms回复的那样，使能fast mesh prov后，会占用底层的资源，因此esp_ble_cur_sendable_packets_nums返回的数据会比较小。当前底层buffer的数量个数是不可更改的，因此无法增加剩余buffer个数，但我注意到你目的是提高OTA的速度，那么建议你参考 examples/bluetooth/bluedroid/ble/ble_throughput，将MTU Size设置成ESP_GATT_MAX_MTU_SIZE，然后每次下发的数据包大小尽量为MTU Size，以最大化地利用每个buffer。