Hi!
The Nano ESP32 seems awesome, but I want to power it with a single-cell LiPo battery. The "official" nano specifications sites either 5V or 6V minimum voltage on the VIN pin.
However, when looking at the schematics and datasheet for the on-board converter (MP2322) it seems like a voltage down to 3.3V / 3.4V should be doable and with higher efficiency rather than supplying dual-cell voltage.
Anyone have any thoughts on this?
The product page says 5-18V
The datasheet says 6-21V but they show a converter efficiency of 90% at 4.5V
The schematic has this disclaimer:
Reference Designs ARE PROVIDED "AS IS" AND "WITH ALL FAULTS. Arduino SA DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, REGARDING PRODUCTS, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
I'd say 5V min
I have the same question as you.
I don't see anything in the datasheet for the step down converter that indicates that 5 or 6V is needed.
The datasheet indicated that V_out is maximum V_in * D_max (where as D_max is the max duty cycle of 96%)
With 3.3V output voltage, then (in theory) the minimum input voltage should be 3.43V?
Will a single cell LiPo work?
It's probably not a good idea, although it seems it should work in principle. Refer to the datasheet of the MP2322 buck converter used on the Nano ESP32-S3.
First issue is this:
Note that below a 4V input the converter will run inefficiently under light loads. Efficiency as such may not be a major concern, so maybe this is tolerable. However, in a battery-powered device, it may not be ideal (the question of course is whether an alternative is preferable, but that's another matter...)
The other issue is addressed on page 13 in the section on low-dropout operation, which shows that the device basically loses regulation at some point - although this exact point is undetermined in the datasheet. Given a low overhead of ~130mV I'd say you're setting up for a borderline case and I'm not sure whether that's a great idea, although again it'll probably work reasonably well.
Are you think that a current measured in volts? 
As stated in #6, the 5v input from USB passed the same regulator, so powering with 5v via VIN should be fine.
There is none
See this post
See this post
@fredrikb, do not hijack. As you can see, you hijacking an existing thread has created confusion. Threads split.
@fredrikb, do not cross-post. As you can see, your cross-posting has wasted several people's time. Threads merged.
What about this part of the spec:
It's "advanced and not officially supported" part of the spec, but still, it's from arduino's site
