My nrf51 SDK version is like this,
nrf51 9.0
softdevice 130
chip:nrf51822_xxAArun ble_central_and_peripheral connectivity example,
The nrf51 board is controlled by host MCU though UART.
When my Host MCU get the connected event,
Call API "sd_ble_gap_rssi_start(m_conn_handle, 10, 0);"
When get the rssi changed event,
Call API "sd_ble_gap_rssi_get(m_conn_handle, &rssi);"
Then I found API "sb_ble_gap_rssi_get" didn't return.
The NRf51 chip seems was frozen.
If I call these two APIs just in the nrf51 chip, such as running ble_peripheral/ble_app_template example.
It works properly.
For resolving this issue, I update the SDK from 9.0 to 11.00,
The freeze issue still exist.
So I think there are problems about the UART comunicate between Host MCU and NRF51.
NRF51 can't handle the "get rssi" command which is from hos MCU.
So it may be a problem of NRF5 SDK.
Could you reproduce this issue between host MCU and NRF51?
Thanks