Hi,
My Arduino UNO was working ok. One sketch was running I tried to upload another sketch while battery was connected. The sketch didn't upload showing the following message.
"stk500_recv(): programmer is not responding". Please HELP
I forgot to mention my desktop is Mac. Other settings are ok.
tx/rx leds dont flicker
pin13 led flashes when manual reset is pressed
previously uploaded sketch is running with sensors and TFT display.