Arduino UNO R4 coming shortly

Looks good! I might actually want to finally use an Uno!

However this could be a bit of a pain, unless VCC can be changed to 3.3V, otherwise level shifters will be needed with 3.3V logic.

Granted lots of industrial interface chips still use 5V, but it would be nice to also support 3.3V in some way for at least a few GPIO, e.g. a few level converters on-board. Still, looks like I2C will work at 3.3V according to the table below (unless Arduino has I2C resistors on-board, I don't know if Arduino boards do that or not; anyway it's not hard to desolder them, lets hope they are not 0201 silliness, if this is an industrial-targeted board).

One great thing with Renesas is the always almost OTT level of documentation, it's a 1400-page extremely detailed reference manual : ) 

Looks good! I might actually want to finally use an Uno!

However this could be a bit of a pain, unless VCC can be changed to 3.3V, otherwise level shifters will be needed with 3.3V logic.

Granted lots of industrial interface chips still use 5V, but it would be nice to also support 3.3V in some way for at least a few GPIO, e.g. a few level converters on-board. Still, looks like I2C will work at 3.3V according to the table below (unless Arduino has I2C resistors on-board, I don't know if Arduino boards do that or not; anyway it's not hard to desolder them, lets hope they are not 0201 silliness, if this is an industrial-targeted board).

One great thing with Renesas is the always almost OTT level of documentation, it's a 1400-page extremely detailed reference manual : ) 

I assume one of the things they strove for was backwards compatibility with all the shields out there, as well as existing projects.   For a lot of people, the biggest "win" will be the memory increases opening up a lot more extended feature possibilities.  It would have been useful to provide a 3.3V option though.  The R3 Uno definitely didn't have on-board I2C resistors.

You've got me trawling through the Renesas RA4M1 spec now...

Spotted this... I will be curious to see how the Arduino R4 handles all these analogue capabilities the chipset offers:

• has both a 14-bit A/D Converter (ADC14) and a 12-bit D/A Converter (DAC12)
• has 2 x 8-bit D/A Converters (DAC8)
• has 2 x Low-Power Analog Comparators
• and 4 x Operational Amplifiers

Hmm. Well the analogReadResolution() call already exists, and did hint at choosing higher values for some "forward compatibility". LSBs will be padded with zeroes where the hardware is not capable of the requested resolution.

I guess analogWrite() can be real analog rather than PWM now too ...

As for the others ... I suppose they'll roll out the new functions assuming they're available and hooked up. Or else, like some more advanced features, people will have to access ports directly and twiddle bits to get the desired outcomes.

- Gough

It would probably be a pleasure using that chip with direct register access, with the detailed documentation with plentiful diagrams etc throughout. Actually, since the part is available in easy-to-solder packages too (QFP and there's a 0.5 mm pitch QFN option too), it would also be often convenient to just directly use the chip without the Uno. Just saw there's a reasonable-price RA4M1 dev-board for one of the 100-pin QFP variants. I'm thinking it could be worth getting that, just to try out the device. It would be nice to try the analog functionality that BigG spotted.

Also it's a nice part for upgradeability in the field, since it has serial and USB bootloader.