want to achieve 1-2 Mbps through BLE.

[Mohsin khan]

I am working on project in which i want to read data from sd card and send it to mobile through BLE , I am using ble_nus_send to send data but when i decrease the delay then its giving me error 19 and when i increase delay then it is running smoothly .

Can i achieve something between 1-2 Mbps through ble_nus_Send or have to do with some other approach . 

[Mohsin khan]

I have encountered the issue 
i did 4 things to increase my throughput 

I changed min and max interval to 50ms

I have removed scan from my code now it just advertises 

void conn_evt_len_ext_set(void)
{
    ret_code_t err_code;
    ble_opt_t  opt;

    memset(&opt, 0x00, sizeof(opt));
    opt.common_opt.conn_evt_ext.enable = 1;

    err_code = sd_ble_opt_set(BLE_COMMON_OPT_CONN_EVT_EXT, &opt);
    APP_ERROR_CHECK(err_code);
}

added this function after ble_scan_init()

and increasing NRF_SDH_BLE_GAP_EVENT_LENGTH in my sdk 

It was giving me throughput of 90kBps and i am satisfied with it . Thanks karl for help . 

[Karl Ylvisaker]

Thank you for the update - I am glad to hear that you have achieved a transfer rate you are satisfied with. It is still not quite the maximal rate, but if this suffices for your application then we may stop the debugging of this issue here.
If you should want to look into this again in the future we will require a sniffer trace to effectively debug any bottlenecks.

Mohsin khan said:

Thanks karl for help . 

It is no problem at all, moshin-khan!

Please do not hesitate to open another ticket if you should encounter any issues or questions in the future.

Good luck with your development!

Best regards,
Karl