@alexcap
I just stacked it normally, it should be 3.3v refering to schematic. The HPWR pins is for the high voltage modules to transfering current like Module PwrCAN or PPS etc.

@alexcap
For me, just providing the correct power supply, you can get NMEA messages over the serial port (even without the antenna plugged in). The only things you need to make sure are the pinouts are correct and the module is getting the correct power supply.

Hello @alexcap

according to the schematic, your SW2 setting and the code example I would say that you should be able to receive GNSS data on GPIO16 with baud rate 38400.

Note: I don't have the M5GNSS module to test myself, so my conclusion could be incorrect. I also do not know if the uBlox GNSS module needs to be activated via software commands in any way.

Thanks
Felix

Hello @paydogs

my M5PaperS3 running the factory test shows about 4.19 V when fully charged and still on USB-C. When I remove external power it drops to about 4.12 V.

Thanks
Felix

Hello @paydogs

I was just about to suggest that from your video it looks like the battery might be flat.

Glad you figured it out.

Thanks
Felix

Hello @scroggyg

the added 5 V power switch I use to fully turn the modem off when I want to use M5Tab5 without modem (without the need to de-solder it.

The other modification to control the POWERKEY of the modem via GPIO (instead of the default auto power on) of the modem is required for two cases:

• firstly to restart the modem in case it becomes unresponsive to AT commands and
• secondly to get it out of PSM (power save mode).

Thanks
Felix

Hello @kuriko

thank you for this information. I just retried M5StampPico with UIFlow1 and changed the Start Mode to USB Mode and back to Internet Mode. In both cases I get the blue light. So I guess it's not connected to the server.

Thanks
Felix

@marnix201
The blue LED indicates that it is currently working in USB mode or is not connected to the server

Hello @scroggyg

in UIFlow2 under Hardware you can find the Watch Dog Timer (WDT) module.

I created a example in the UIFlow2 Project Zone: M5Tough_Watchdog_Test_UIFlow2.2.8

Thanks
Felix