Reset during UART send/receive

RE: Reset during UART send/receive

Jared — Tue, 20 Aug 2019 14:22:48 GMT

Hi,

I've reproduce the issue and see that a APP_UART_COMMUNICATION_ERROR is raised, more specifically an OVERRUN error due to the CPU not being able to process what's in the buffer before new data is sent during a reset.This causes the application to hard fault. You could try enabling Hardware Flow Control and see if the issue persists.

Jared

RE: Reset during UART send/receive

toruish — Fri, 16 Aug 2019 00:32:03 GMT

It reproduced on ble_app_uart_c_pca10056_s140 sample.

During writing to serial port, nRF52840-DK does not boot by Reset button.

Steps

1) Build and run ble_app_uart_c_pca10056_s140 sample on nRF5_SDK_15.3.0_59ac345

2) nRF52840-DK LED1 blinks every 5sec.

3) Run python script to keep writing to Serial port

4) Press "IF BOOT/RESET" button on DK.

5) Boot failed, LED1 does not blink.

If I remove uart_init() and printf() on sample main function. That test case is success, I can see LED1 blinks on step 5.

I run this python script on iMac for step3.

import serial

def testSerial(tty):
  ser = serial.Serial(tty, 115200, timeout = 1)
  while True:
    ser.write(b'hello\r')
    print("w");

testSerial('/dev/cu.usbmodem0006833998061')

RE: Reset during UART send/receive

Jared — Wed, 31 Jul 2019 13:31:23 GMT

Hi,

It should be fixed in the newest SDK. Do you experience the same issue with the unmodified example from the SDK?

regards

Jared

RE: Reset during UART send/receive

toruish — Wed, 24 Jul 2019 17:14:43 GMT

I use SDK 15.3.

Do you know nrf_drv_usbd_errata.h::nrf_drv_usbd_errata_type_52840_fp1 issue is fixed on 15.3?

RE: Reset during UART send/receive

Jared — Wed, 24 Jul 2019 08:36:57 GMT

Hi,

Which SDK version are you using? Could you try the suggestion in this thread and see if the issue is still persistent.

regards

Jared