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10 years, 6 months ago.
Should I need to pull up the D- & D+ pins.
I have made a program which displays data (text) through LCD.The program also supports RS232(serial) & USB interfaces.But now when I switch on the system the program displays data only while USB is connected later(after power on).How can I rectify that ? Should I need to pull up D- (p32) & D+ (p31) pins of the USB ? Thanks for the reply in advance.
1 Answer
10 years, 6 months ago.
How are you powering your circuit?
If you are using 5v from VU to power the LCD then it will only work when the USB is connected as VU is the USB 5v line and isn't powered from Vin.