Leonardo RX and TX LEDs are always on!

I got an Olimex Leonardo (Olimexino 32u4), which is based in the arduino Leonardo design.
I’ve installed the newest bootloader, so that case is OK.
The “problem” is that the RX and TX leds are always turned on, even though im not using the serial monitor or communicating with a computer. This doesn’t affect the programming, but is really annoying, since these leds are really bright. Whe are these leds always turned on?
The green LED is TX, and yellow is RX. The small, red led is the power led.

Pic is attached

I've tried to reinstall the newest Leonardo bootloader, but no luck. However. There was no diffrence when I burned the Esplora bootloader, but when I burned the Micro Bootloader into the leonardo, the leds acted normal. Have this happend to any of you?

  • I had an old version of this board lying around for some time. Never got it to work nicely with the old Arduino IDEs...

As it was one of the first boards, it still had an outdated bootloader on board. Flashed now with the 1.5.2-IDE the new Leonardo-bootloader and encountered the same problem you are describing here: TX and RX pins are always "on". As these guys are quite bright on that board, that's kind of annoying...

Well, the solution turned out to be simple: change the board type in the Arduino IDE to "Micro" (just below the Leonardo-listing). The first time you upload code, the board will reconnect again, your OS (I have done this under WinXP) will detect a "Micro", requesting to install new drivers. Do this. This will get the TX and RX leds into the right mode, i.e. only signalling traffic, not constantly "On".

Note that the serial port the device is attached to will change during this procedure. Check your device manager for the new port and set it correctly for further uploads.

So in summary: seems that the IDE has some issues here - when the IDE thinks it talks to a "Micro", everything is ok. When it thinks it talks to a "Leonardo", the TX and RX LEDs of the Olimexino stay always on.

I have not checked whether the Leonardo bootloader is different from the Micro bootloader and what the IDE is doing differently. But with my board has still having the Leonardo bootloader "on board", selecting "Micro" as board works fine.

Best, cpixip.