There is a bug in the nrf_libuarte_async.c file :
PPI_CH_SETUP(m_ppi_channels[PPI_CH_RXRDY_CLEAR],
nrf_uarte_event_address_get(UART_DRV_UARTE, NRF_UARTE_EVENT_RXDRDY),
nrfx_timer_task_address_get(&m_timer, NRF_TIMER_TASK_START),
nrfx_timer_task_address_get(&m_timer, NRF_TIMER_TASK_CLEAR));
The first argument to the macro is "m_ppi_channels[PPI_CH_RXRDY_CLEAR]". The macro itself is defined as:
#define PPI_CH_SETUP(_ch, _evt, _tsk, _fork) \
ret = nrfx_ppi_channel_assign(m_ppi_channels[_ch], _evt, _tsk); \
if (ret != NRF_SUCCESS) \
{ \
return NRF_ERROR_INTERNAL; \
} \
if (_fork) \
{ \
ret = nrfx_ppi_channel_fork_assign(m_ppi_channels[_ch], _fork); \
if (ret != NRF_SUCCESS) \
{ \
return NRF_ERROR_INTERNAL; \
} \
}
As you can see, the macro uses "m_ppi_channels[_ch]" instead of just "_ch", which expands to the invalid "m_ppi_channels[m_ppi_channels[PPI_CH_RXRDY_CLEAR]]" expression
