Long time no post - have y'all missed me?

I'm working on a new project with multiple goals in mind: 1) Have fun 2) Learn about circuit design 3) Gain proficiency with KiCad.

My Project is a Microcontroller based board of LEDs. I would like to power it from USB or Battery.

What I am trying to do is use the MOSFET to toggle the PWNEN pin on the FT232 but I'm confused now.

Here are cropped out areas in question:

and..

I've attached my full schematic below.

Thank you in advance!
doc

 

My Project is a Microcontroller based board of LEDs. I would like to power it from USB or Battery.

What I am trying to do is use the MOSFET to toggle the PWNEN pin on the FT232 but I'm confused now.

That makes two of us.
It's not clear to me what toggling the PWNEN pin with a MOSFET has to do with powering the project from a USB or Battery.

And where exactly on the schematic is the problem?

 

Also be careful with using global labels, they can be a powerful tool, but lead to problems as well.

 

not clear to me what toggling the PWNEN pin with a MOSFET has to do with powering the project from a USB or Battery.

I did not state that accurately. If I am understanding the data sheet properly for the FT232RL - the PWREN pin goes high when the FT232RL has cycled up properly. I need to better understand how the MOSFET will work as drawn. I do not think it is right yet.

And where exactly on the schematic is the problem?

at the MOSFET?

 

Also be careful with using global labels, they can be a powerful tool, but lead to problems as well.

. I had planned on multible sheets at first but it all fits pretty good on one. Could you help me understand where global labels might lead me astray? I do appreciate the help and enjoy learning!
doc

 

. I had planned on multible sheets at first but it all fits pretty good on one. Could you help me understand where global labels might lead me astray? I do appreciate the help and enjoy learning!
doc

@crutschow will answer your MOS questions, he is good at it.

When using global labels and the design becomes more complex, its easy to put a global label at the wrong place and there will be no error shown. After you produce the PCB with the "KiCad" gerber files, it becomes very hard to debug it.

Also the other reasons are here:
https://forum.kicad.info/t/local-label-with-direction-hierachical-labels-without-erc-warning/6164

 

at the MOSFET?

I don't see a MOSFET at the PWNEN pin.

 

When using global labels and the design becomes more complex, its easy to put a global label at the wrong place and there will be no error shown. After you produce the PCB with the "KiCad" gerber files, it becomes very hard to debug it.

I understand. I will reserve global labels for another day. Thanks!

I've made some finishing touches - here's the result.

@crutschow I think you may be picking on me but just in case here's the MOSFET pointed out.

If that's not legible the full PDF is attached. Thanks!

I really do appreciate y'alls input!
doc

 

@crutschow I think you may be picking on me but just in case here's the MOSFET pointed out.

Not really.
I just missed the two nodes being the same notation and connected together.
But I'm still missing the PWNEN node.

 

I goofed and the arrows I drew are on an older iteration version - the attached file is correct though. I also mistyped in the original post PWNEN node should be PWREN - sorry. It connects to the CBUS3 pin on the FT232.

Also it's renamed in the new version to USB_PWR_EN. I can crop out a close up if you don't want to download the PDF in my last post.

Sorry I mess up so much - I do appreciate your persistence.

doc

 

 

And the rest...

 

Okay, now that that's straightened out, what exactly do you want to happen as you go from battery power to USB power, and from USB power back to battery power?
What is the sequence of events?

 

I would like too be able to:
1. Power the board from USB or Battery.
2. Be able to have both applied simultaneously.
3. Switch from one to the other without resetting the MCU.
4. Overvoltage indication

 

I just noticed I left out a an electrolytic capacitor at the VIN/Barrel Jack connection.

 

Switch from one to the other without resetting the MCU.

What will control that occurrence?
Will the battery voltage always be greater than the USB voltage?

 

Switch from one to the other without resetting the MCU.

What will control that occurrence?

Now that I've thought about it that is not concern. Just one source or the other is OK.

Will the battery voltage always be greater than the USB voltage?

I'm not committed to the final physical design yet. For now the battery will be and external source via battery pack; so yes - likely 6V- 12V.

Your questions are thought provoking! I do appreciated your guidance!
doc

 

Now that I've thought about it that is not concern. Just one source or the other is OK.

If you don't care then why have two sources?
You still need something or someone to make the decision as to which is connected.
What if one source is not available?
Do you want it automatically to connect to the other?

 

If you don't care then why have two sources?

Perhaps I misunderstood your question. Let me give it a think.