Best posts made by ws1088

@dda what a wonderful work you have done! I hope this will enable @Multihelix to use M5StickC as a watch (turn off OLED after a timeout and turn on OLED on button press or accelerometer)

@staind87 said in Problems with the I2C Grove Interface:

Hello dear M5Stack Team,

I come from Germany and unfortunately my English is not perfect.
I hope you can understand me.

I think the 5MStack product line is really good. It's all in a nice case and the products are well made.
Now I unfortunately noticed a few things which are not so beautiful, but maybe I didn't see it correctly.

It's about the I2C Grove interface. I think there are some hardware design bugs.
Unfortunately I can't see the I2C Grove interface in the schematics of the M5Stack.
Therefore I assume that SCL and SDA from the Grove interface are directly connected to the ESP32. (without logic)

Now to the problems:

1. A level shifter is missing in the M5Stack.
   If I look at the schematics of the sensors (e.g. the ENV unit) I can see that the pull-up resistors in the sensor modules are connected to 5V (VCC).
   
   
   This means that 5V is connected to the inputs of the ESP32. The ESP32 only supports voltages up to 3.6V. The 5V voltage could demage the I2C inputs of the M5Stack.
   With a level shifter in the M5Stack this problem could be solved.

2. The pull-up resistors are built into the sensors.
   Unfortunately the pull-up resistors are built into the sensors. This is very unfortunate because if I use the Unit Hub to use several sensors then I have several pull-up resistors parallel to my I2C bus.
   
   The total resistance of the pullup is getting smaller and smaller due to this.
   So maybe bigger circuits can't work anymore because the pullup resistance is too small.

Why is the pull-up resistor not installed centrally in the M5Stack?

I hope you don't misunderstand me. I love the M5Stack, but I noticed these problems.

Greetings from Germany

Staind

I recently have problems with using both ENV unit and TOF unit on a I2C hub on M5StickC. Using just 1 one of them at one time works. I wonder if this is related to what you discovered?

Also, would using a PaHub solve the problem?

I solved the problem. I googled to: http://forum.m5stack.com/topic/841/m5stickc-driver-no-work/7 and find the location to the Windows 10 driver needed to M5StickC (https://www.ftdichip.com/Drivers/VCP.htm)

I downloaded the zip file, extract it. Then I plugged the stick to the computer and open device manager and see the "M5Stack Intf" missing-driver device and go to "property" to update driver. I selected manually specify the location of the driver (to the top-level folder of the extracted folder). It will installed the "M5Stack Intf" driver. Then another missing-driver device will show up (USB serial converter). I did the same as the first device.

After this is all done, a new COM port will show up (your COM port number will differ from mine).

Good luck all! I strong suggest this to be documented. It's sad to see documentation and software limiting the robust hardware.

I charged the unit for a long time and then powered it OFF (by long pressing the power button). After a few hours I cannot powered it on again. Looks like it is out of battery.

Is this an unexpected behavior?

I have the Env Hat and it blocks the IR and LED. I don't have the Hat with me now, I can check tonite and update you if it is otherwise.

Since the power button is not a real physical switch (but a push button), there are bounded to be current used up. And who knows what UiFlow launcher (I am using version 1.3.2) or the OS is not doing when we long press the power button. :(