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Using Arduino => Microcontrollers => Topic started by: octopope on May 22, 2019, 12:34 am

Title: Nano 33 BLE Battery
Post by: octopope on May 22, 2019, 12:34 am
I've pre-ordered a pair of Nano 33 BLE units as they look pretty outstanding, but I have a question as to power.   I'm looking to run these via battery but I'm a uncertain if I'm reading the specs correctly.  Does the VIN support 5V power or only 3.3v?  The note on the order page mentions that it "only supports 3.3V I/Os and is not 5V tolerant" 

So, would supplying 5v to the VIN be a super duper bad idea?  I'm thinking yes, but would love for more insight into this so I can order the proper bits beforehand and not destroy these boards as soon as they arrive.

Cheers!
Dan
Title: Re: Nano 33 BLE Battery
Post by: pert on May 22, 2019, 05:45 am
The product page doesn't provide a description of how to use the VIN pin and also doesn't supply a schematic so there is currently no way to answer that question. I'm sure Arduino will provide a schematic for the board eventually.

My assumption would be that VIN is connected to a voltage regulator which will reduce some range of voltage down to the 3.3 V the microcontroller and other components on the board run at but that's only a guess.

There is a Vusb pin, which is referred to as the "5V" pin in the rest of the documentation (because that's the name of the pin in that position on the classic Arduino Nano. Of that pin, the documentation says:
Quote
the 5V pin does NOT supply voltage but is rather connected, through a jumper, to the USB power input.
We know for certain that the board has a voltage regulator connected to the 5 V input from the USB connector to reduce it to 3.3 V. So if you use a dab of solder to close the Vusb jumper on the bottom of the board, you could power the board at 5 V via the Vusb pin. Note that, if you do that, the microcontroller will still be running at 3.3 V with 3.3 V logic levels and you must be careful not to subject the board's IO pins to 5 V logic input.
Title: Re: Nano 33 BLE Battery
Post by: mathlete on Jun 12, 2020, 11:33 pm
Hi, though it's not too easy to find, it is written on the Nano 33 BLE box as 4.5 -21 volts required for input. So 5 volts is fine.
VIN is also listed as requiring "5-21 volts" on the Nano 33 BLE Pinout file that can be downloaded.
Title: Re: Nano 33 BLE Battery
Post by: Klaus_K on Jun 13, 2020, 08:07 am
The product page doesn't provide a description of how to use the VIN pin and also doesn't supply a schematic so there is currently no way to answer that question. I'm sure Arduino will provide a schematic for the board eventually.
The schematic is under documentation in the store product page.

https://store.arduino.cc/arduino-nano-33-ble-sense (https://store.arduino.cc/arduino-nano-33-ble-sense)

The best power supply depends on your application. For lowest power follow the FAQ section on the same store page. The onboard step down converter is not very low power friendly, it is designed for a very large input voltage range. That is why there is a jumper/bridge on the underside to disconnect the MPM3610 and use a battery or other 3.3V power source. But this should be done only when you finished developing your software.
Title: Re: Nano 33 BLE Battery
Post by: pert on Jun 13, 2020, 10:54 am
My response was accurate at the time I made it a year ago. Fortunately, Arduino has since provided that information. Thanks to you both for taking the time to provide a 2020 update for this thread.