Revised XIAO Round Display Schematics

The schematics and board layout files for the round display on the wiki are for the original version of the board.

Whilst the changes to the schematic for the additional KE switch are fairly trivial, the board layout has changed significantly in order to accommodate the dip switch.

Would it be possible to provide the schematic and (more importantly) board layout files for the newer version, please?

thanks,

Matthew

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I thought I’d add the reason for wanting the board layout for the revised round panel display.

pin D6 can be used to switch the LCD backlight on or off. R18 is a pull-up resistor on this output so that the backlight defaults to on when D6 floats (which makes sense).

I’m using the ESP32S3 - if you put that into deep sleep to save battery life, D6 floats, and the backlight comes on, pretty much undoing any advantage of using deep sleep mode. Unfortunately whilst the RTC can drive some of the GPIO pins in deep sleep this is limited to certain “RTC” pins - pins 1 - 21 on the S3. D6 however is connected to GPIO49 - there’s a related issue with pin D7 which had it been connected to a GPIO pin in the range 1 - 21 would allow touching the lcd display to wake the S3 from deep sleep, unfortunately D7 is connected to GPIO50.

I’m currently using light sleep mode which doesn’t have these restrictions, but would like to eek out a little more from the battery, so I’m looking at options which I suspect involves hardware hacking (although if someone knows better, please do let me know!).

From the round display schematics there is a DNP resistor R33 to ground, so simply* moving the 100K resistor from R18 to R33 looks like it will change D6 from a pull-up to a pull-down. However, I need the board layout to find the locations of R18 and R33, and I have the later KE switch version of the LCD.

Matthew

* yes, I know this involves desolding/soldering smd components with the risks involved!

Hi there,
WOW Nice breakdown , Technically. I think “Yes” to your changes to work.
Too bad no-one designing the display ever took these considerations involved into account, I think it’s a systemic situation in Seeed engineering. Over looking the main sale points about battery power and being suitable for wearables. Things like battery monitoring(esp32c3) and the Libraries to go with their hardware and changes are left to the users to figure out. kinda WEAK IMO.
The hardware is pretty good though, and the support here will help getting the latest info available.
HTH
GL :slight_smile: PJ

FYI

Hi there,
Yea that’s all that’s known about it, but OP needs the board layout…
I don’t have access to that.
GL :slight_smile: PJ