Hello guys

the M5Cardputer doesn't have that hold button until green LED lights up mechanism. To put M5Cardputer into download mode use the method described here.

If you want to enter download mode, press and hold the G0 button on StampS3 before turning it on, then release it after powering it on.

Thanks
Felix

Hi guys

Here is an explanation as to why it may take some time to fix: M5CoreS3 uses the SPI bus in a special way to control the LCD: MISO (normally an input) is reconfigured to be an output and is used as DC line (instead of a dedicated GPIO for DC). Unfortunately to access the SD card (which shares the SPI bus with the LCD) MISO needs to be an input.

In case you might be interested. I found a way to do this switching back and forth between input and output for Arduino.

Thanks
Felix

Hello @jamstooks

@ajb2k3 is correct, the PbHub is for analog devices only and cannot be used for UART.

Unlike UART, I2C is a bus and can handle multiple units (as long as the units use different I2C addresses). So if you want to connect multiple I2C units to you M5Core2 you can use a Groove-T.
However as soon as some units you wish to connect share the same I2C address you need a different solution. You have two options:

• the units in question allow for the I2C address to be modified
• use a PaHub (like @ajb2k3 suggested)

As for connecting the UnitV2 to your M5Core2 via UART: I would suggest the Battery Bottom 2, which has been designed for M5Core2 and it gives you the UART port needed.

The COMMU module should work as well, but as it has been designed for the M5Stack (Basic, Gray, Go, Fire) there seems to be some incompatibility issues like while the COMMU module is stacked to the M5Core2 the M5Core2 cannot be flashed.
(Note: I don't have the COMMU module, so I cannot confirm that issue.)

Thanks
Felix

Hello @m5stack

thank you for letting us know about the latest UIFlow 1.7.3 firmware. I appreciate it.

It is however very unfortunate that the M5Core2 PaHub bug has not been addressed in this update. I'd appreciate if your engineers fix that bug in the next update.

Or, as stated already many times in many places, please open source the UIFlow code so we can help you fix issues like that.

Thank you for listening.

Felix

Hi guys

an M5CoreInk with ESP32 in light or deep sleep still consumes a couple of mA (which is to be expected given the hardware architecture). However M5CoreInk allows to shutdown ESP32 completely and later wake it up from the RTC timer or alarm.

For an M5CoreInk in shutdown mode I've measured a current (at the battery) of only about 2.5 uA which is pretty good. And yes, the ink display retains the last image.

Cheers
Felix

Hello @hacxx

please stop posting incorrect / not very useful information. W5500 is different from ENC28J60 and therefore EthernetENC or UIPEthernet library cannot be used for W5500. Thank you.

Thanks
Felix

Hello guys

my M5Cardputer takes about 7 hours for a full charge from a completely discharged battery state.

Note: I soldered two LEDs to the charger IC CHRG and STDBY outputs and it switched from charging to standby after about 7 hours.

Thanks
Felix

Hello @Bipman

by default Port A is meant for I2C, but it can be used for I/O (Port B) or UART (Port C) as well.

Note: But please be aware, that it can be only one type of port at any given time. Also, since its default use is Port A (I2C) there are internal pull-up resistors (10 k) in place on both lines which might have a negative effect when used in a different mode.

If you need Port A and Port B at the same time there is the PbHUB unit which can be used to connect some of the Port B units.

If you need all three types of ports (A, B and C) together then I am afraid M5Cardputer is the wrong device to use as core. There are simply no more GPIOs available for a dedicated Port B and/or Port C. Please see schematic here.

Thanks
Felix

Hello @Surya

after long hours of searching and debugging I found the reason why I2C would fail. It starts to fail as soon as SSL is invoked. The SSL library uses an analog GPIO as input for its random seed. And in your code you used GPIO2 which is one of M5AtomS3 Groove GPIOs.

So to get rid of the I2C error try changing the GPIO used for random seed to GPIO10.

//SSLClient ethClientSSL(ethClient, TAs, (size_t)TAs_NUM, 2);
SSLClient ethClientSSL(ethClient, TAs, (size_t)TAs_NUM, GPIO_NUM_10);

Thanks
Felix

Hi guys

even though I read the warning about not using certain types of chargers with M5PaperS3 I managed to do so anyways.

Suffice to say, M5Paper released some magic smoke and wouldn't start anymore.

I cracked it open from the back (as I think the eInk display is glued in) to get access to the board. (I do not recommend doing that as it is a destructive process.)

With the eInk display and touch disconnected I started to inspect the board.

I found the charger IC USB-C protection diode pack being dead from the look of it. I removed the charger IC (as it is not strictly needed to run) I replaced the USB-C protection diode pack and found the MosFet IC getting pretty hot. So I removed the MosFet as well and injected some voltage (4.2 V) after the MosFet which revealed that the 3.3 V regulator took some hit as well. I replaced the 3.3 V regulator with a similar one I took from an M5Atom.

With two ICs MosFet removed and the 3.3 V regulator replaced M5PaperS3 took a reasonable small amount of current. I also measured ok voltages for the eInk display so I dared to reattach the display and touch screen and yo and behold - M5PaperS3 is alive again.

Now I need to order some replacement ICs MosFet.

You can see the opened M5PaperS3 and the dead ICs here.

Thanks
Felix

Hello @foofera

hmm, the I2C communication working in setup() suggest the wiring is ok.

Are you using pull-up resistors on intSCL and intSDA?

Have you tried lowering the I2C bus speed?

Have you tried to put a delay between issuing I2C commands in your loop() code?

Have you tried to control a different I2C slave device from your STM32? Does that work in both setup() and loop()?

Thanks
Felix

Hello @xgonc

no, I did not try any other Ethernet library.

Thanks
Felix

Hello @xgonc

maybe try with a short delay() before the first loop?

BTW: the included PoE example works for me.

Thanks
Felix

Hello @bensonwhlee

try adding a delay(500) before calling pbhub.begin(). My above linked code fails to initialize PbHub without a delay.

Thanks
Felix

Hello @wjcarpenter

the battery charging IC is TP4057 and battery voltage is measured via R40 / R41 into GPI38. See second page of the schematics here.

Thanks
Felix

Hello @bensonwhlee

I think you need to use the M5StamPLC library together with M5Unified and M5GFX libraries for it to work properly.

Please find an example here which works for me.

Edit: if you don't need M5StamPLC specific functions then it should be sufficient to add the following line to your setup code:

Wire.begin(2, 1, 400000U);

Thanks
Felix

Hello @teastain

I am afraid I cannot help, sorry. I exclusively use Visual Studio Code with PlatformIO / pioarduino (which so far doesn't have this issue).

Note: Visual Studio Code / PlatformIO doesn't use M5Stack boards and setting up new Cores (M5Stack and others) can sometimes be quite difficult as well.

Thanks
Felix

Hello @peolsolutions

you are starting to confusing me.

Your posts often are quite vague and not specific to M5Stack hardware / software.

Also why would you post a very similar response again about a month after your last one? Doesn't make sense to me.

Care to explain you reason(s) for doing that?

Thanks
Felix

Hello @smily77

according to the schematic GPIO15 is used as reset pin (SOC_EXTRF_RST).

Thanks
Felix

Hi guys

corresponding github issue for reference.

It seems there isn't an easier way just (yet) than using Espressif Library Builder.

Thanks
Felix