BLE shield write string

if you do not want anything more with BLE shield and print strings

void WriteBLE(String message)
{
if ( ble_connected() )
{
byte bericht[message.length()+1];
message.getBytes(bericht, message.length()+1);
ble_write_bytes(bericht, sizeof(bericht));
}
ble_do_events();
delay(10);
}

There is no reason why the function should take a String as an argument. Write the code properly, so it does not need to extract the data wrapped in a String.