Hello, I wonder if I could connect BT (bluetooth) by pressing a key to sand a command on Arduino board and turn it off to upload a sketch. At first glance it worked well. I could upload a sketch and when switch serial port to establish communication with bluetooth. I could receive signals from bluetooth, but when I tried to sand a command, everything freezes. I guess it’s a problem with synchronization of signals. for details, I added a transistor on VCC pin of bluetooth. Maybe I should try to connect a transistor on RX pin? I know I could use SPDT witch… but am interested in writing a sketch to make a digital switch for bluetooth.