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,

Thanks the quickly response, I read some post and it seems the issue still on going ? no final example code available ? you mentioned that you have some improvement in it what's the final result/conclusion ? In my case I just repeated transfer 20 bytes every one seconds , it should be enough time and should not get BLE_ERROR_NO_TX_PACKETS result in theory, but it happened which means has problem, skip put new data into stack if not success seems to avoid the problem not fix the problem in deep inside. Could help provide new "uart_app_uart" sample files (I use SD110 8.0 ) so I can test here to check if it ok for such simple testing case.

Another question is about increase throughput by using the BLE 4.2 large data package (> 20 bytes) , do you know can use on nRF51 device just update FW/SW to support BLE 4.2 is ok or need use new chip such as NRF52 ? any document, post to teach user how to upgrade to BLE 4.2 ?

Thanks