int ring_buffer_append(struct RingBuffer *ring_buffer, char value) {
if (ring_buffer_full(ring_buffer)) {
return -1;
}
ring_buffer->buffer[ring_buffer->tail++] = value;
ring_buffer->tail %= ring_buffer->size;
return 0;
}
SEXP R_ring_buffer_full(SEXP extPtr) {
return ScalarLogical(ring_buffer_full(ring_buffer_get(extPtr, 1)));
}
bool_t usart0_tx_buffer_full(void)
{
return ring_buffer_full(&usart0_tx_ring_buffer);
}