Revised-1 Schematic Diagram of ArduinoMEGA

The underlying statements refer to the schematic of the attached file:

  1. I have given connector(s) numbers as CON1, CON2, ... as a matter of convenience on the MEGA board.

  2. CON2-2X and CON2-2Y appear as having PCB connections inside the board. Physical measurement
    using DVM shows 5V at both points.

  3. CON7-7X pin appears to be 'a not connected pin' like UNO.

  4. IOREF is connected too 5V.

  5. MEGA board shows a symbol: RESET-EN. It is not found in 'Arduino Mega 2560 Reference Design'

  6. Hope the circuit will be useful!

ArduinoMEGASchematicdoc.pdf (108 KB)

RESET_EN - there's a trace marked there that you can cut to disable autoreset, and pads that you can bridge with solder to re-enable it.

What is wrong with the official schematic?

Why have you started another topic for this post? I'd merge it with your other if my browser would let me.

I'd put the SCL/SDA marking back on the pin pairs that had it - top 2 on the upper right and D20/21. They measure 5V because they have a pullup resistor on them.

IC1/IC2, why not show the 5V regulator and the auto-switching that goes with it?
Same with the LEDs - why not used a regular LED symbol? You use regular diode, resistor, capacitor symbols elsewhere.

It's a pretty good attempt to show the Mega schematic as more of a block diagram, maybe use for those not comfortable reading a schematic.

DrAzzy:
RESET_EN - there's a trace marked there that you can cut to disable autoreset, and pads that you can bridge with solder to re-enable it.

What is wrong with the official schematic?

Nothing wrong with official Reference Design; simply, it has not included what we have on the physical MEGA
board.

CrossRoads:
Why have you started another topic for this post? I'd merge it with your other if my browser would let me.

I'd put the SCL/SDA marking back on the pin pairs that had it - top 2 on the upper right and D20/21. They measure 5V because they have a pullup resistor on them.

IC1/IC2, why not show the 5V regulator and the auto-switching that goes with it?
Same with the LEDs - why not used a regular LED symbol? You use regular diode, resistor, capacitor symbols elsewhere.

It's a pretty good attempt to show the Mega schematic as more of a block diagram, maybe use for those not comfortable reading a schematic.

https://www.arduino.cc/en/uploads/Main/arduino-mega2560_R3-sch.pdf

  1. I tried to edit my original post with the Revised Schematic; but, as I could not do that I opened a
    new post.

  2. OK! I will put signal names against all pins.

  3. I will revise my schematic.

Thanks for the encouraging comment!

"Nothing wrong with official Reference Design; simply, it has not included what we have on the physical MEGA
board. "
The official schematic has the Reset Enable solder jumper shown on the far right side of the page.
It looks to be shorted out as that is the defaul state unless one cuts the trace running between the two pads.