Please does anybody have any idea what is going on? Step 1 Upload the AnalogReadSerial example to my uno. Step 2 I have connected pins TX - RX _GND to a 9 pin serial connector and with a null modem to my PC Step 3 I have open Hyperterminal and I read to my Hyperterminal screen the analogue values from arduino fine.
Problem If I disconnect USB cable ( power off arduino ) when arduino restart it doesn't send anything to my serial port. If I upload again the sketch through usb cable everything works fine I can understand what is going on!
If I upload another example such as blink after disconnect usb cable and connect again power off - on the arduino example blink works fine.
thanks in advance !!