I would like to know if there is an arduino that has a Vin range of atleast 5-12v . I know that you can power a nano or uno directly 5v via the 5v pin but i would like to not keep swaping between 5v pin and Vin pin whenever the source voltage changes
The Nano 33 IoT will do. If you prefer the classic AVR, there is a 3.3 V version of the Pro Mini, but you'll be pushing the upper limit of its linear voltage regulator at 12 V
The short answer is that they all will. The longer answer is yes, but don't even think about it. The inbuilt regulators have either no or minimal heatsinking. That means that trying to run more than just the board and a few LEDs will lead to overheating and shutting down.
The correct method to deal with varying Voltages is to use a regulator externally. For digital circuits, a buck (switched mode) regulator is efficient and ideal for the job. If your circuit is low level analogue, then a linear regulator would be best, fitted with a decent heatsink.
There are buck/boost converters that can take a large range of voltages and produce a constant 5V output regardless. That can be part of your solution.
However I can't help but wonder: why would your input voltage suddenly change to begin with?
Unlike the classic Nano's linear voltage regulator, the Nano 33 IoT uses the MPM3610 buck converter:
Unlike the classic Nano's linear voltage regulator, the Nano 33 IoT uses the MPM3610 buck converter
The newer generation Arduinos do have built-in buck converters, but they all are 3.3volt logic.
Many classic sensors can't be used with those without signal and power problems.
The newer very different generation is not very well documented and supported by this forum either.
Maybe because the geriatric gurus here don't want to switch to a significantly more expensive board that does basically the same in most projects.
Maybe just add a buck converter to your classic Nano, like most of us do.
I think it has been something like 6.5 years since the first official ATSAMD21G18-based board was released. Although the Nano 33 IoT is only 1.5 years old, it takes advantage of all the accumulated SAMD support that came before it. The main thing that is newer about the board is the ESP32-based WiFi radio, but even that has some previous history in the MKR WiFi 1010. I'm a big fan of the AVR boards, and certainly they have a head start of years when it comes to support, but the SAMD support is getting pretty mature now.
As for the Nano 33 BLE, it's definitely early days for that architecture in the Arduino world.