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I am looking at making a schematic for the ISM330DHCX alongside a ATmega328P processor for Arduino. I have the Adafruit version of it (LSM6DSOX is same footprint).

Schematic:

enter image description here

PCB:

enter image description here

I just wanted to see if half of the components on them are neccessary. My intention is to only do I2C communication, with no need for interrupt pins, Chip Select etc.; only Voltage, SCL, SDA, ground.

The ISM330DHCX datasheet has the connections guide below, from what I can tell all I should need is:

  • AP2112K-3.3: Voltage Regulator for 5V to 3.3V
  • 2*10kOhm Resistors: for Pull-up in I2C
  • 2*100nF Capacitors: for Power Supply decoupling
  • EDIT: Logic shifter for SDA and SCL

Is there anything else I am missing?

Also I read up on VDD and VDD_IO, I am assuming for my application both are connected to 3.3V with no problem.

I appreciate any help, thanks!

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  • \$\begingroup\$ Are you going to run the ATmega328P at 5V? If so, shouldn't do level shifting for SCL and SDA? \$\endgroup\$
    – Codo
    Jan 27, 2021 at 7:06
  • \$\begingroup\$ I did have a look at that and from what Ive seen it can run at 3.3V but I will use a level shifter just to keep within specifications, I think now the only other thing im uncertain about is if the CS pin needs to be wired a certain way to ensure it doesnt use SPI, there isnt anything else I should be worrying about is there? \$\endgroup\$
    – daethat
    Jan 27, 2021 at 10:18
  • \$\begingroup\$ You can run the ATmega329P at 3.3V (at 8MHz max if I'm not mistaken). Then you don't need level shifters. \$\endgroup\$
    – Codo
    Jan 27, 2021 at 10:27
  • \$\begingroup\$ Page 9 of the data sheet is very specific. CS needs to be connected to Vdd for your setup. \$\endgroup\$
    – Codo
    Jan 27, 2021 at 10:30
  • \$\begingroup\$ Perfect, I do however need the ATmega328P at 5V for the product so I am happy to use the level shifters, I think the only thing I am unsure of now is if the extra resistors on the adafruit schematic are neccessary. I am happy to implement them, just want to minimise the footprint if possible \$\endgroup\$
    – daethat
    Jan 29, 2021 at 1:09

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