Context : I am using a nrf52832 to communicate via UART to a STM32 on a custom board. I've based my work on the Ble nus service example. Main change from the DK is that i don't have an external 32khz so i enabled NRF_CLOCK_LF_SRC_RC
I recently updated the nrf52832 code from SDK12/s132 version 3.0 to SDK14 /s132 version 5.0 because i had issues with some Android devices.
Problem : The BLE part is doing fine now with all the devices that were causing trouble (advertisement, connection, characteristic reading/writing) but the UART part is now unstable.
Hardware flow control is enabled UART_DEFAULT_CONFIG_HWFC, baudrate is set to 115200. On the SDK14, i've tried UART_EASY_DMA_SUPPORT but it's not working, so i switched to using UART_LEGACY_SUPPORT.
At first, uart communication is good at transmitting / receiving but after a while, the connexion hang and i have to reset the whole board. The uart_event_handle doesn't seems to have a APP_UART_COMMUNICATION_ERROR or APP_UART_FIFO_ERROR event but what happen is a high state on the CTS pin of the nrf52. Also, UART_RX_BUF_SIZE value seems to change the delay/latency after which i have this problem.
After debugging i did get those two info from the uart :
EVENTS_CTS 1 EVENTS_NCTS 1 EVENTS_ERROR 0 ERRORSRC 0
Can someone give me hints on what to look after ?
(already saw devzone.nordicsemi.com/.../ and checked the pinout)
EDIT: the high state is on the RTS pin of the nrf52 not the CTS (blue line is RTS, yellow is RX)
