Nrf51 UART example code has problem!

[chtsai]

Dear Sir,

Here I test the ble_peripheral example "ble_app_uart" (Softdevice 8.0) with Kail MDK ARM 5.20 environemt on the PAC10028A board.

I found it's not stable and alwasy will happen error (auto disoccnect) after continue notification a while.

Here I use the nRF Connect/MCP APP in my android phone. the UART I/F is connected to PC(Win10) and run a uart tool (Serial port utility) I use it to send 20 bytes message ex. "0123456789001234567890" to the PCA10028 and it will notify to MCP the received message. It works for trying serveral time but always fail (auto disconnect) after send many times. I set the 1 second repeat action(send 20 bytes) in the tool still has same problem no need wait too long(within 30 seconds) will see the situation. I chang the repeat sending period to 5 seconds and modify default baud rate to 9600 bps(FW) still has same problem.

1. Here we have BLE UART bridge applications, and need good and stable solution. It is easy to duplicate the situation, could help try, find and fix the root casue of the example code.

2. Our application should need higher throughput by UART, I know the BLE 4.0 ,4.1 has limitation (20 bytes, package delay time etc.) but Is it possiable to achieve higher if upgradte to BLE 4.2 , and Nordic is ready to provide BLE 4.2 more data bytes package to help our applcaition ?

Thanks your help!

[Stefan Birnir Sverrisson]

Hi

You are correct, the ble_app_uart example code has a problem. When throughput gets high, the application will assert. There is a preliminary solution described in my answer here, which contains an improved ble_app_uart code.

[chtsai]

Dear Stefan,

1. Here I clearified my case it's different , no error code just restart but I found the reason, my uart adapater(usb2uart) connect to PC has problem, after change another one (different brand) not exist the situation, I don't want wast time to check why this usb2uart adapater has problem.

2. I used the BLE_EVT_TX_COMPLETE event to send arrived UART RX data should be no BLE_ERROR_NO_TX_PACKETS error. Is it still exist problem with higher throught according your experience ? (115200bps ok ?) in your experiment ( can up to 128Kbps).

3. BLE4.2 can also update in nRF51 , no need to change chip to nR52 right ?

Thanks