GROVE I2C 5V or 3.3V?

JiKuch

M5Stack is the perfect platform for the professional design of own solutions.
I have received first CORE development kit wit ESP32 and tested Arduino examples.
I have not encountered an unsolvable problem.

However, I would like to ask you to clarify the following:

What does HPWR represent in M-BUS? What is it good for?
I did not find the GROVE I2C connection in the schematic. Since it contains 5V power level, does it mean that both SCL and SDA have a 5V pullup (with level conversion to ESP32)? Or is SDA and SCL connected directly to GPIO21 and GPIO22 without level conversion and need to keep up to 3.3V for GROVE SCL and SDA?

Thanks in advance for your answer.

on4aa

I have exactly the same questions. Especially, what is HPWR and how is it connected?
The designers should urgently answer this question.

on4aa

From this discussion, I gather HPWR is meant to be VBUS, the power received directly from the USB port.

m5stack

HPWR is used to be the driver power, such as 12V or higher, we will use in the new modules, for example , the motor driver /PLC/ etc.
GROVE is 5V, SDA and SCL is 3V3 Pullup. SDA=G21, SCL=G22;

lim

The conclusion is that the 5V Vcc cannot connect to 3.3V device.

GregFordyce

@on4aa said in GROVE I2C 5V or 3.3V?:

From this discussion, I gather HPWR is meant to be VBUS, the power received directly from the USB port.

HPWR appears to be an isolated power bus that is not connected to any of the power busses on the M5 Core, but can be used between modules that may require higher voltages.

lukasmaximus

If you want to use a 3.3v device in the grove port you would need to create an adapter to step down the voltage, I designed a simple pcb that did this with a voltage divider. It worked for the simple led ribbon that I wanted to turn on and off, but if you wanted to use an analog or more complicated sensor you would also need to implement a logic level converter

Johnny241

@lukasmaximus comment faire pour implémenter ce convertisseur de niveau logique?

lukasmaximus

@johnny241 said in GROVE I2C 5V or 3.3V?:

@lukasmaximus comment faire pour implémenter ce convertisseur de niveau logique?

https://au.element14.com/adafruit/757/logic-level-converter-4ch-arm/dp/2301651?gclid=EAIaIQobChMI293Q_s-Q6wIVFR4rCh2mQgi4EAQYAiABEgKglvD_BwE&mckv=s_dc|pcrid|432287894085|pkw||pmt||slid||product|2301651|pgrid|102205443084|ptaid|aud-471864486199:pla-902298347457|&CMP=KNC-GAU-GEN-SHOPPING-EMBEDDED-COMPUTERS

http://www.farnell.com/datasheets/1683643.pdf?_ga=2.12967607.1498586764.1597062128-969722884.1596265857&_gac=1.39987734.1597062128.EAIaIQobChMI293Q_s-Q6wIVFR4rCh2mQgi4EAQYAiABEgKglvD_BwE