ble_uart demo throughput is very slow

[Nomados]

Hello Nordic,

I am using the BL600 third-party module and SDK 10. I was able to modify and compile project with GCC at examples\ble_peripheral\ble_app_uart\ for s110. It works nice, but the transfer speed is very low (around 500 Bytes/s). When I send a big chunk of data via UART, the module sometimes just hangs up. Definitely this example is not suitable for production. I have read all topics with descriptions about increasing the speed, but w/o success. Maybe Nordic can provide some good example for handling big amounts of data via BLE UART? Maybe with results of transfer speed for some evaluation board...

[Petter Myhre]

Ok. It is in 1.25 ms units, so when you connect you have a connection interval of 48.75 ms. You can try to decrease the connection interval by sending a connection parameter update(CPU) request, but the central can reject it. I'm guessing that you already have included the connection parameter module, it will send a CPU request 5 seconds after connection is establised. It will send the CPU request with the MIN_CONN_INTERVAL and MAX_CONN_INTERVAL values defined in main.c Then you can check the BLE_GAP_EVT_CONN_PARAM_UPDATE event if the actual connection interval changed or not. See this MSC for more information. You can find the small connection interval by trying and failing.