I was so excited when I saw in the pinout diagram that Tx and Rx LEDs are on PD5 and PD4, which implies that I could control them using D5 and D4. Similar to how D13 controls the built-in LED and yet we still could use D13. Alas, that is not the case with the Rx Tx LEDs.
Looking at the schematic, it becomes clear that the PD5 and PD4 controlling the Tx and Rx LEDs are on the ATMEGA16U2 that handles the USB port. Completely separate from PD5 and PD4 on the ATMEGA328P-MUR that are within our control.
You can see the confusing pinout diagram and the clear schematic here
I hope someone with privilege would remove the PD5 and PD4 from the Rx Led and Tx Led in the pinout diagram. It is irrelevant what port those LEDs are since normal users cannot control those ports.
[sterretje edit]
fixed url
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