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LilyGO / T-Koala

GNU General Public License v3.0
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Detailed schematic? #2

Open davidjade opened 4 years ago

davidjade commented 4 years ago

I would like to see a more detailed schematic. I have several questions:

  1. What is the blue LED for? (I think it is a LIPO charging status of some sort)
  2. I found a limited schematic that shows IO25 connected to a MOSFET between VCC3V and +3V3. What does it do? It seems it might control the VCC3V on the U11/U12 headers?
  3. There seems to be a place for a switch. What is its purpose and what are the connections?

A more detailed schematic would answer these questions and more.

viappidu commented 3 years ago

Possibly? https://myosuploads3.banggood.com/products/20190611/20190611221357TTGO32TYPE-C.pdf Doesn't look like to me

lechndo commented 7 months ago

Hi,

I got the same board and have some troubles with switching the 3V3 enable MOSFET via IO25 and I'm not sure if I'm doing something wrong or if the circuit has some issues.

During normal operation the pin is currently low and I have proper 3V3 supply, but in low power mode I want to shut 3V3 off to disable some peripherals.

The problem is, that the pin doesn't come higher than around 0.2V. From what I can see, the pin is correctly defined as output and set high during shutdown.

Does this work for you? Any ideas what could be wrong?

EDIT: I found a working solution for my issue. In RUN the pin gets configured as output and is set to low. For the shutdown I simply reconfigure the pin to mode pullup.