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Powering Grand Central M4 from shield
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Powering Grand Central M4 from shield

by Solcellespesialisten on Tue Mar 30, 2021 8:28 am

Hi,
We are planning to create a shield that will have an MBUS slave chip (TSS721A) that is connected to a energy meter that can provide up to 700mW to the MBUS slave.

Is it possible to power the Grand Central M4 from a shield if no USB or external powersupply is attached. If so what PINs and what voltages should I use?

Solcellespesialisten
 
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Re: Powering Grand Central M4 from shield

by adafruit_support_bill on Tue Mar 30, 2021 8:50 am

You can supply 5v-12v power from the shield via the VIN pin.

https://learn.adafruit.com/adafruit-gra ... -3015119-3

adafruit_support_bill
 
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Re: Powering Grand Central M4 from shield

by Solcellespesialisten on Wed Mar 31, 2021 3:11 am

Thanks.
I was unsure since I did not measure any connection between the external power connection and Vin when external power was disconnected.

Solcellespesialisten
 
Posts: 3
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Re: Powering Grand Central M4 from shield

by adafruit_support_bill on Wed Mar 31, 2021 7:02 am

There is a diode and MOSFET switch between the DC input jack and the VIN pin. That is used to detect which power source (USB or DC jack) to connect to VIN.

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Please be positive and constructive with your questions and comments.