I am looking at the schematic and it shows a precision voltage divider on this pin. I have been digging through the datasheet and manual for the micro and I cannot find any reason for this voltage divider.
I want to use some of the functionality of an UNO 4, and the ease of programming it through the arduino ide, but there are things I simply don't have any use for (LED matrix) and there are enhancements I need (like an external antenna option on the ESP) - so I am trying to do my own layout with/without those items.
I can find nothing about why there is this voltage setting on this pin. This pin does not go out to any external connector. The micro documentation is HEAVY. But I am not seeing anything in it related to any of the multiple functions assigned to this pin regarding why you would connect it to a voltage divider.
Can anyone shed any light on htis?
Do you understand we can't SEE anything.
Start by reading the pinned post 'How to get the most from this forum'
Then come back and tell us what you are trying to do followed by what you have done (show us the code) and what you expected plus what really happened.
This has absolutely nothing to do with code.
See the attached excerpt from the schematic. This pin goes no where user accessible on the original Arduino board, and does not go to any other IC on the board. It is not used as some sort of I/O, and I haven't found anything in the datasheet for the Renesas processor about needing to set a voltage level on this pin, but they have used very precise resistors as you can see.
Since I am not planning to use the original board, I want to understand the purpose of this voltage being set on this pin. What function is it for. I need to determine if I can let it float, or if I need this specific voltage, or some other voltage.
Educated guess. To measure the 5volt VCC rail of the board against the internal 1.5volt reference with an unused analogue input (ANalogue 016).
0.1% smd resistors are not that uncommon.
Leo..