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

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

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

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

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 @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 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 @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

Hello @koreanEggCoffee

yes, that is possible - I am powering my M5Atom this way.

However please note: There is no protection against wrong polarity so please be careful not to accidentally swapping 5 volts and GND.

I also suggest you disconnect the external 5 volts before connecting USB-C. Or in other words only connect one power source at the same time.

Please also refer to the M5Atom schematics which outlines the 5 volts connections between USB, 5v pin, Groove, LEDs and 3.3 volts regulator.

https://docs.m5stack.com/#/en/core/atom_matrix

Cheers
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 @mm-uiflow

yes, I think to successfully connect to blynk.cloud.com the template id is required as well. See here - check section [IMPORTANT] a bit down the page.

I've done a quick test with Arduino Blynk code and my M5Core2 connected immediately. But with UIFlow my M5Core2 doesn't connect at all.

I think UIFlow Blynk blocks need to be adapted to the new template id requirement.

Thanks
Felix

Hi guys

if you look closely you'll find that the schematics for M5Atom Matrix and M5Atom Lite are not completely the same. Apart from the RGB LEDs (25 vs 1) only the M5Atom Matrix has an MPU6886 internally which is controlled via I2C using GPIO21 and GPIO22.

However with the ATOM Stepper Motor Driver GPIO21 and GPIO22 are used for RST (Reset) and EN (Enable).

Therefore only M5Atom Lite can be used to control the ATOM Stepper Motor Driver.

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

Hello @rdlaner

on my M5AtomS3 (with display) I measure about 257 uA in deep sleep when powered via Groove port 5 V and running this code.

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 @gcormier

Unfortunately M5Paper doesn't have a charging indicator (eg. LED) and as you already noticed yourself the reported voltage is of almost no use either.

The thing is that the charger IC used in M5Paper has two outputs (charging and standby) which would indicate if the battery is being charged or not. Sadly though the M5Stack engineers decided to not use those outputs.

I did some measurements with my M5Paper and on average it did not take more than 3 hours to fully charge the battery.

So I suggest you keep it charging for at least 3 hours and it should be full.

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

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 guys

M5Stack has defined three Groove ports A, B and C.

• A (red) is by default used for I2C (found on M5Core2)
• B (black) is by default used for DAC / ADC (found on M5GO Bottom2)
• C (blue) is by default used for UART (found on M5GO Bottom2)

that said, from the perspective of the ESP32 almost any GPIO can be used for any function. Or in other words the above is not set in stone, but only what M5Stack has decided to use as their default.

So, yes, you could use the two GPIOs on port A as standard GPIOs. In Arduino you'd just wouldn't initialize I2C on these two pins and then you could use for something else.
In UIFlow that would happen (automatically) if for instance you attach the relay unit (which is an UART device) to port A and then use the respective relay blocks.

Regarding the PbHub: this is an I2C device which by default is plugged into port A. It has 6 ports, each providing an input and an output. These 12 pins are controlled by an microcontroller inside PbHub and the available functionality is limited to a given set. Check the list at the bottom here.

Now, in Arduino you use this library which takes care of sending the proper I2C commands to lets say turn on the output pin on PbHub port 1. Or read the input pin on port 6.

In UIFlow if for instance you connect the relay unit to PbHub port 2 (instead of directly connecting it to a Groove port) you then use the PbHub specific block to control the 6 ports on PbHub. Again which I2C command that requires to be sent to PbHub is done automatically by the UIFlow firmware.

So, for your project, @cerietke, using OpenHASP, the OpenHASP firmware for M5Core2 would need to know about PbHub to be able to control the ports on PbHub. I don't know anything about OpenHAB so I cannot tell if it could deal with PbHub or not. That is probably an question on the OpenHAB forum to ask.

Thanks
Felix

Hello @PK_Pippin

you are correct, there is a conflict on GPIO33 which on M5Core2 is used for external I2C (SCL) and by the Lora868 module as CS.

The reason is that on the original M5Stack (core) the same two GPIOs (21/22) were used for internal and external I2C. For M5Core2 the two I2C busses have been split and the external I2C now uses GPIO32/33.

I guess one solution would be to switch to an M5Stack (core) instead of M5Core2 (core2).

Another solution might be to use the Ext Port for Core2 which gives you Port E (GPIO27/19) to use with the CardKB.

Please note: While I did check in UIFlow 1.12.5 that Port E is offered for CardKB I do not have the necessary hardware to test either of my two proposed solutions. So there might be other issues I haven't foreseen.

Thanks
Felix