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Xinyuan-LilyGO / LilyGo-EPD47

GNU General Public License v3.0
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SCHEMATIC #18

Closed Kabron287 closed 2 years ago

Kabron287 commented 3 years ago

When you launch new product, the FIRST and MANDATORY thing that must be done is the SCHEMATIC of the product! That is why you lose the competition with M5Stack products.

vke commented 3 years ago

https://github.com/Xinyuan-LilyGO/LilyGo-EPD47/issues/2#issuecomment-757875009

Kabron287 commented 3 years ago

Thanks! I guess it have to be placed in hardware folder of this repo.

vke commented 3 years ago

Yes, with 3D model of PCB exported from Altium.

Kabron287 commented 3 years ago

I noticed that dual DC/DC converter U2 could not be shutdown. Are there free MCU pins to route to SHDN1/SHDN2 pins of U2?

fdufnews commented 3 years ago

I was expecting POS_CTRL and NEG_CTRL from the shift register U3 were used to do that. They are set or reset in epd_poweron and epd_poweroff in the software of the epd driver. Seems they are here just for nothing. Maybe there is a reason they provide the signals but didn't route them. We'd like to hear about this from the designers

Edit: PWR_EN is switching off 3V3 that is powering the dual DC/DC, when working on the battery.

lewisxhe commented 3 years ago

The schematic has been added.

vke commented 3 years ago

The schematic has been added.

Please add also PCB 3D model file (STEP?) exported from Altium where PCB was designed

Kabron287 commented 3 years ago

It seems to me that correct naming for this position should be VBAT. Am I right? VBAT

fdufnews commented 3 years ago

I think your wrong VBAT is coming throught Q5 and is applied to the "5V" net, when there is no power on USB plug otherwise VBUS is present on "5V' net. From "5V" net, VBAT (or VBUS) is applied to the BAT net when Q3 is on. And Q3 is on when VBUS is present or PWR_EN is active.

Kabron287 commented 3 years ago

OK, but net BAT on Q3 drain is connected only to R29 and nothing else. Maybe some nets are not named or some another mistake?

Kabron287 commented 3 years ago

So, the only purpose of the Q3 is to connect battery to ADC divider R29/R32 in order to reduce leak current while device is in deep sleep. But, look at R35. It is permanently connected to battery and consumes ~40uA. It'll be better to change R35 to ADC divider which lower consumption at least twice.

lewisxhe commented 3 years ago

I have updated the explanation, the voltage divider is not always enabled, only when the operation screen is turned on.

https://github.com/Xinyuan-LilyGO/LilyGo-EPD47/blob/b0d619d5fc610bb522ccb7fcf263670c6f8f999a/examples/demo/demo.ino#L113