Best posts made by felmue

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

Hi guys

I've started to code a simple touch keyboard. I am still experimenting but I thought I'll share what I have so far.

You can find more pictures here: https://www.gwendesign.com/kb/m5stack/m5core2/#simple-touch-keyboard

You can find the code here: https://github.com/felmue/M5Core2/blob/fm-touch-keyboard-1/examples/Basics/keyboard/keyboard.ino

Happy Stacking!
Felix

Hello @ajb2k3

my apologies - I only read the comment of the M5Cardputer documentation w/o trying it myself.

Thanks
Felix

Hello @tomtom22

G1 and G2 are available on Port A. You are correct, G38 and G39 are not available as general IO on the M5AtomS3. They are used for I2C (and yes. the IMU is already connected to them) but additional I2C devices can be added here. M5AtomS3 documentation can be found here.

Thanks
Felix

Hello @david-bethesda

I think you might have misread @ajb2k3's answer. What he meant is to use the web UI (because the Desktop app version is out of date).

Note: the Desktop app version has not been updated in ages - I would not recommend to use it.

Thanks
Felix

Hi guys

I've created an example showing how to partially update the ink display after the system gets powered on via RTC from a full shutdown. Pull-request

Cheers
Felix

Hello @jimbo_s

you'll need to have two I2C instances, Wire1 for internal stuff (AXP, Touch, RTC, etc.) on pins GPIO21 and GPIO22 and Wire for your sensor on pins GPIO32, GPIO33.

The M5Core2 library already set Wire1 up for the internal stuff:

Wire1.begin(21, 22);

so your sensor should use Wire. You can enable that on the correct pins by calling:

M5.begin(true, true, true, true);

the last true sets Wire up:

Wire.begin(32, 33);

You probably need to change the library for the sensor to use Wire instead of Wire1. How that is done depends on the library. Some allow to pass in the I2C instance to be used and some need to have every instance of Wire1 replaced manually to Wire.

The key here is to not mess with Wire1 else you loose all I2C communication within M5Core2.

Cheers
Felix

Hello guys

@ajb2k3 : hmm, I've just double-checked with my M5Cardputer following your video and the LED does not light up. Maybe it depends on what firmware it currently runs?

@HankTTTop : yes, that is normal behaviour - at least my M5Cardputer does that as well - it starts up as soon as USB is connected - even when off. (It is my understanding that the ON/OFF switch is for the battery only.)

BTW: have you tried a different USB cable?

Thanks
Felix

Hello @jeetS

without a common GND, e.g. COM.X GND not connected to USB to TTL GND and then measuring the voltage between the two is not very useful in most cases. That is why, when two circuits which are powered from different power sources, a common GND is required.

Anyhow if you power COM.X without RX connected to anything and then measure between RX and GND and you only get 1.7 V then yes, that is probably too low.

If I do the same then I get 3.3 V between RX and GND.

I use this USB TTL converter set to 3.3 V.

Maybe this article about common ground can help.

Thanks
Felix

Hello @sheepDog

I've put together some code which takes the camera picture and puts it onto the LCD of the M5CoreS3. You can find it here.

Thanks
Felix

Hi guys

Power consumption update: even though the example keeps the M5CoreInk in shutdown mode (everything off except for the RTC) most of the time and only powers up for about 2 seconds every minute to do the update, the built in battery only last for about one week.

Thanks
Felix