iiuc, it's a leakage current at an IO pin configured as input and connected to a high impedance output (or left floating). Not the most common situation (leaving an input unconnected is bad practice anyhow) and there are workarounds (expect an updated errata with those soonish). The RP2350 has some features which make it interesting for applications where a RP2040 doesn't fit (e.g. secure OTP storage).
And for the vast majority of cases the chip is fine, I2C is fine, the ADC is fine (despite what hackaday says), the SPI is fine, GPIO output is fine, GPIO input-with-pull-up is fine, GPIO input-with-pull-down needs a stronger pull than usual, 4K7 works great.
The use-cases where you have problems are being blown way out of proportion IMHO. All chips have errata, there are workarounds to most of this one’s issues, and there are alternate solutions for the few cases where it can’t be worked around. This is normal.
I’d also point out that there’s a guy on the RPi pico forum who’s successfully linked a touch-sensor input to the RP2350 without problems…
It had sounded to me like the input pins were going to burn an extra 100uA or so per pin, over potentially dozens of pins. That's a lot of power for an MCU. Do I misunderstand?
It was nice using RPI's in their golden era. That is now over. This story will continue to repeat itself until we take a more honest look at our current economic systems at play.
I've ordered one and am confident for anything I'd do it's not an issue. Usually any input I have is connected directly to the output of something else and that provides the path for the leakage current. If that isn't true, e.g. a button, then I'm using a pull-up and thus also not affected. Certain analog measurements could be affected, but again not if they have a low impedance (i.e. strong) source. The current is around 100 microamps so it's not stressing the source much.
It's unfortunate that this is happening in the chip that so massively improved the low power sleep states. Designs needing wake from sleep on pin change with an active high / inactive high-z signal are not going to be good. That requires a strong external pulldown and will be constantly burning those 100ish microamps. That doesn't sound like much, but it's a lot of power for being asleep.
Still I'm very excited for the improved CPU performance and even more RAM. Once mine arrives I'm going to see how much faster it can do some fixed point DSP than the RP2040.
[1] https://github.com/raspberrypi/pico-feedback/issues/401#issu...
