It would be nice to have more pins.

Just thinking aloud, there is already i2c, spi, serial, digital and analogue. also going to a mega really goes against the idea of low power. ???

Cheers Paul

Thanks for the ideas. We're researching other options, including an ARM version, which has much more pins and peripherals but also offers great low-power features!

This is not about pins. This is about RAM and flash. As much as I love atmega328p, I cannot do two-three sensors with debug and signing. I also have to optimise the code to use as less space as possible. DualOptiboot takes as much space as a normal arduino bootloader so cannot use Optiboot if I want to have an OTA.

Please check out atmega1284P (Still AVR and would satisfy 90% requirements) or ARM SAMD.

Talk2 wrote: Thanks for the ideas. We're researching other options, including an ARM version, which has much more pins and peripherals but also offers great low-power features!

A good idea. Something like Murata CMWX1ZZABZ can be used for that.