Powering I2C Devices

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JoshuAc00k
 
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Powering I2C Devices

Post by JoshuAc00k »

Hello. I want to communicate to three ATtiny85 chips as I2C slaves with a Raspberry Pi as the master. These chips will have various jobs including controlling 5V relays, neopixels, 5mm LEDs, monitering switches, etc. I'm not sure, but from what I've read it sounds like the Raspberry Pi won't be able to power all of these devices. Can I power the ATtiny85's from a separate power source and just connect all of the grounds, or do they have to be powered by the RPi?

Thank you for any help!

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adafruit_support_mike
 
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Re: Powering I2C Devices

Post by adafruit_support_mike »

Using a separate power supply and connecting the GNDs will work. They just need a common reference voltage.

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JoshuAc00k
 
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Re: Powering I2C Devices

Post by JoshuAc00k »

Is the connected ground the reference voltage?

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adafruit_support_bill
 
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Re: Powering I2C Devices

Post by adafruit_support_bill »

Yes. The ground is your common reference.

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JoshuAc00k
 
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Re: Powering I2C Devices

Post by JoshuAc00k »

Okay! Great, thank you!

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