I just made another discovery. If you power it up with the factory demo software, go the home screen, and then tap on "CORES3" six times, it puts you into a factory test mode

And on further examination, there's the dark grey PB_IN and PB_OUT pins, at G8 and G9. The splash screen when you power it on shows G8 and G9 are on Port B (there's a typo, saying "Port.C" but it's in the position of the black Port B connector).

Looking at the pinout diagrams with some refreshed eyes and I see it now... "PA" is short for "Port A" and "PC" is short for "Port C". And PA has a red background, like the red Port A connector, and PC is in the same light blue as Port C's connector.

@felmue
Hi Felix! Good to hear from you again!

Thanks for the clarification! The second serial connection is the blue connector, right?

Hi all!

I just got my first CoreS3 yesterday. I've been using the original Core with COM.LTE modules for a product/project I've been working on. I'd really like to start using the CoreS3 instead, as it has so many more features that are perfect for my project. But it looks like the M-BUS connector has a slightly different pinout. Am I able to use the COM.LTE with the CoreS3?

By default, the COM.LTE uses pins 5 and 13, which are listed as the GPIO and IIS_WS pins, respectively. On the CoreS3, those same pins are PA_SCL G1 and GPIO G7. Is the PA_SCL pin the SCL on the external red I2C connector? I do need that for some sensors.

I could use the DIP switches to change from using pin 5 to using 15 or 16. 15 was formerly IIS_OUT but is now I2S_DOUT, which I'm assuming is for the speaker, which I need. 16 was formerly RXD2 but is now PC_RX G18. Not sure what that pin is for.

Thanks! I'm so excited to get this new unit going!

aezero

Hi all,

From what I've read, there isn't a way to monitor the battery level on a Basic Core ESP32 using the Arduino IDE. Is there at least a way to monitor if the battery is present (ie that it hasn't failed)? There's M5.Power.isCharging(), but that will show as true even with the battery removed.

Thanks!

@flypeek It definitely compiles smaller! I got it down to around 250KB with the SerialMon disabled. The only issue I have is that it doesn't light up the backlight on the screen. I can see the text is there if I hold up a flashlight to it. Any idea how to light it up? I've been doing some searching, and it doesn't look like it's a simple HIGH/LOW sent to pin 32. The M5Stack.Lcd library says it's PWM controlled.

Thanks!

That helps! Thank you!

I'm going to drop the SerialMon stuff too. I only added it just in case I had a unit with a faulty screen, but then I realized that if the screen were faulty, no one would see the message to bring it back to me. And why would I want a unit with a faulty screen? LOL!

Hi all,

I'm going to be deploying a bunch of M5Stack core units with LTE modems. I have been writing a small firmware that I can push to them OTA in case a unit gets lost or stolen. This way, the original firmware if replaced with a "if found, return to..." message. It's very simple but still compiles to 346KB, which does not OTA very quickly (Carrier problem. I have another thread that explains why.). I'd really like to get this to a smaller size, if I can. Is there a way to either optimize the compiler to shed code that it doesn't use (ie. wifi, etc), or can I manually trim down the M5stack library?

Thanks!!

#define SerialMon Serial

void debug(String msg) {
    SerialMon.print(msg);
    M5.Lcd.print(msg);
}

void debugln(String msg) {
    SerialMon.println(msg);
    M5.Lcd.println(msg);
}

void setup() {
    M5.begin();
    SerialMon.begin(115200);
    M5.Lcd.clear(TFT_BLACK);
    M5.Lcd.setTextSize(3);
    M5.Lcd.setTextColor(TFT_WHITE, TFT_BLACK);
    debugln(F("If found, call"));
    debugln(F("xxxxxxxx"));
    debugln(F("xxxxxxxxxxxxx"));
    debugln(F(""));
    debugln(F("or return to"));
    debugln(F("xxxxxxxxxx"));
    debugln(F("xxxxxxxx"));
    debugln(F("xxxxxxxxxxxx"));
    debugln(F("xxxxxxxxxxxx"));
    }

void loop() {
}

Hi all!

I figured I'd update this thread with my findings. I've been running a unit in my non-insulated plastic shed for two months of Canadian winter with no problems whatsoever. The screen turned on immediately and is perfectly fine. No unexplained lockups, reboots, or other glitches.

It has been a relatively warm winter (unfortunate for my testing). Inside the shed, it got down to -15C one weekend, but for the rest of the time, it has been between 0C and -6C. Humidity has been an average of 78% with a peak at 97%.