@pbatch You can use an external 5V source and bring it in through the USB port.
Alternately connect it to the battery charging port (if there is no battery connected to it.)
-Terry

@luffe LilyGO products...generally yes, they charge all the time while plugged in to USB.
You should conduct a simple test with your actual unit, as the documentation is very sparse.
(I could not find a schematic for your board)
-Terry

@cchobbyfun
Well, Arduino IDE 2.0 is much nicer to use with very little learning curve!
ESP 2.0.11 board defs are most likely mandatory but older ones may still work.
I would update all libraries and, then, I would copy the contents of the Lib directly to your libraries and overwrite all, as 'replace'. In that order.
["I typically download the zip from Git Hub and launch from the extracted files. Is that good enough? If I have that local file structure do I need any of the libraries installed? "] should be OK.

@teastain2 Perfect, thank you Terry!

Also, thanks again for your feedback on the video. I've just updated it on Youtube (it will take up to 80 minutes for the High Quality versions to be available) but even what's there now is much better. Here's the link: https://youtu.be/YdbTDYZ2Ues

Rob

It's shared now.

https://qiita.com/nak435/items/206a23ef783dc8d6b035

@roblatour

Cool beans...looks like a cool project/device for those who have YouTube accounts, nice job.

Sorry for my silence, T-Int-POE module. I am using SD-CARD as well. I did address GPIO 16, 4 accordinlgy

@bombbaza
In my repository setup text I suggest you contact me by email for off-line one to one help.
-Terry

@chano This is a community site and does not seem to be moderated by LilyGO.
It is mostly just me, a user...
(crickets...)
Post your question and I will have a go!
-Terry

@oragion : Hi Guillaume, did you succeed finally? What do you think of the Lilygo card? I am currently thinking of using the SIM7600 version, with the same operator as you, but I've not purchased the Lilygo board yet.

Thanks for that info.

For anyone else that stumbles across this in the future: what I ended up doing was setting up a simple voltage divider (https://randomnerdtutorials.com/how-to-level-shift-5v-to-3-3v/) and connecting the 3.3V output as an input to one of the GPIO pins, set to pull down.

When the TTGO board is running on battery, the 5V pin I'm using for input from the external power supply becomes a 5V output, which backfeeds into the 5V rail I'm using to detect external power. To solve this, I put a diode between the external power rail and the 5V pin on the TTGO board. This does result in some voltage loss when operating on external power, so I've been advised to use a Schottky diode instead, but I haven't tried that yet.

So far, so good!

@teastain2 Bingo! that worked, changing
Wire.begin();
to
Wire.begin(26, 14);

so pinout for I2C on T-relay 8X is
SDA: pin 26
SCL: pin 14

thank you!