BLE_APP_UART Locks up with high datarate

RE: BLE_APP_UART Locks up with high datarate

ovrebekk — Fri, 01 Sep 2017 07:40:50 GMT

Hi Evgeny

If you have multiple links running they will have individual buffers. In other words you will be able to send data to peripheral2 even if peripheral1 has run out of buffers.

Best regards

RE: BLE_APP_UART Locks up with high datarate

Evgeny Erlihman — Thu, 31 Aug 2017 21:12:47 GMT

Hi Torbjørn,

Thank you so much! I am now able to successfully send "large" data from Central to Peripheral. If i had multiple Peripherals connected to one Central, would it be the same TX buffer? Would i be able to send data to peripheral2 if ble_nus_c_string_send to peripheral1 returned with NRF_ERROR_RESOURCES?

RE: BLE_APP_UART Locks up with high datarate

ovrebekk — Thu, 31 Aug 2017 06:59:44 GMT

You won't use notification on the client side, notifications are sent from the server to the client, not the other way around.
Instead you will use write commands or write requests.
Have you checked if you receive the BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE event?

Best regards

RE: BLE_APP_UART Locks up with high datarate

Evgeny Erlihman — Wed, 30 Aug 2017 21:04:44 GMT

Thank you for the example. I am using the latest SDK with S132 and trying to send data from Central to Peripheral. If i send several bytes, i do see them on the peripheral side, but i do not get the BLE_GATTS_EVT_HVN_TX_COMPLETE on the central. I think i am missing something in the setup or something else. I am using the ble_app_uart_c and ble_app_uart examples with just modifications in the central to send "more" data, for now, i am sending multiple buffers of 4 bytes in a "large" loop. Can you please point me at what i might be doing wrong?

RE: BLE_APP_UART Locks up with high datarate

ovrebekk — Wed, 30 Aug 2017 08:36:35 GMT

I tried to make a variant of the ble_app_uart example that delays transmission when the NRF_ERROR_RESOURCES error is returned, but I haven't tested it extensively. If you want to have a look at it you can get it here: nrf52-ble-app-uart-flow-control.zip

Best regards

RE: BLE_APP_UART Locks up with high datarate

Evgeny Erlihman — Tue, 29 Aug 2017 20:52:41 GMT

What is the right way to send "large" amount of data? Should i retry sending in case i get the NRF_ERROR_RESOURCES?

RE: BLE_APP_UART Locks up with high datarate

Drewster — Wed, 16 Aug 2017 03:28:39 GMT

Many thanks! Happy to see this chugging along - simply added an if() statement to abandon sending the sentence and then break.

RE: BLE_APP_UART Locks up with high datarate

ovrebekk — Tue, 08 Aug 2017 10:12:52 GMT

Hi Drewster

The most common issue with ble_app_uart is if you overflow the BLE stack, since the NRF_ERROR_RESOURCES error is not handled properly in the code.

Are you able to check if you get this error at any time as a return from the ble_nus_string_send(..) function?

Best regards
Torbjørn