Pages: [1]   Go Down
Author Topic: TX diode don't get fired with unplugged USB  (Read 317 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 1
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi All.


I compiled standard sketch. It prints a message to the serial port.
If I power arduino with USB TX diode fires when message is transmitted.

TX doesn't work if arduino is powered through pins (5v and gnd).

Diode of 13 port blinks regularly (it's my check) in any case.

I tried to connect 2 arduinos tx -> rx and rx -> tx
but diodes still not fires.

Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 618
Posts: 33959
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

The TX diode is controlled from your computer not from the arduino. So it will not light up if it is not connected to a computer.
Logged

Dallas, TX USA
Offline Offline
Faraday Member
**
Karma: 67
Posts: 2688
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

The TX & RX LEDs are controlled by the USB to serial chip
not by circuitry that monitors the TX and RX lines connected to the AVR chip.
Logged

Pages: [1]   Go Up
Jump to: