Arduino Forum

Development => Suggestions for the Arduino Project => Topic started by: tigger on Nov 12, 2019, 03:54 pm

Title: Uno Rev 3 schematic
Post by: tigger on Nov 12, 2019, 03:54 pm
I was looking at this forum item https://forum.arduino.cc/index.php?topic=256096.0 (https://forum.arduino.cc/index.php?topic=256096.0) trying to work out where the solder pads for RESET ENABLE went.
Bilcat - I think that was his name - is absolutely right. The schematic is wrong and I am surprised it is still uncorrected.
The official schematic shows two parallel paths from the 328P reset line to the 0.1uF capacitor.
You have one path which looks like a solid trace and another shown as the solder blobs on the PCB.
Cutting the link in the blobs or re-soldering it makes no difference as the solid path maintains the connection.
I haven't buzzed it all out yet, but I suspect the solid path does not exist.
There is also a solder link shown on the 16U part of the schematic, but unless that is well hidden, doesn't exist on my board (official Uno Rev 3).
Throw in some untidy text (component values) in the RESET ENABLE region and maybe it's time to do a little tidying up.
This item gives a bit more information https://rheingoldheavy.com/arduino-from-scratch-part-11-atmega328p-dtr-and-reset/ (https://rheingoldheavy.com/arduino-from-scratch-part-11-atmega328p-dtr-and-reset/)
Title: Re: Uno Rev 3 schematic
Post by: westfw on Nov 14, 2019, 12:23 pm
The schematic is fine.  The solid wire and the two pads overlap on the pcb (which is intended.)