What happened to the M8RXD and M8TXD tracks (circled in yellow) on arduino uno pcb ? If this is a timing issue, can anyone with arduino uno board hardware design experience explain to me in details ? It looks to me that M8TXD track is longer than M8RXD track in actual board layout.
Besides, what are the purposes of 1K resistors connected in series along the M8RXD and M8TXD signal lines ?
the funny thing is that on the board there are 2 via holes that are not shown on the screenshot. See here: Can anyone help to confirm the difference?