Yessir, thank you for highlighting it for me. That table does not capture the info that GPIOs are Schmitt trigger on reset. Documentation is hard. Well, it's easy to win on a forum by pointing things out, but it's much harder to write high-quality documentation. I'm highlighting the latter.
Obviously for some APIs the SDK correctly hides low-level information from the SDK user, this is par for modern helper SDKs since even I am moving towards using module PCBs these days. But hardware_gpio is more low-level than I2C whatnot, and may benefit from some low-level info.
Anyway, I tried my Pico board just now with a 68K external resistor pullup. My cheap multimeter reports 3V3 = 3.24V and the pullup R makes it 0.84V on the input pin. Which makes the pulldown about 24K. But the DS reports a R(PU) R(PD) mix-max of 50K-80K. Hmmm... how many sigma is that min-max? Good documentation can help users to avoid tripping here and there. Well, being a Pico newbie, I'm not expecting the sun or the moon from the RPi folks -- I'm just trying to get a more precise mental model of this chip I am using.
Obviously for some APIs the SDK correctly hides low-level information from the SDK user, this is par for modern helper SDKs since even I am moving towards using module PCBs these days. But hardware_gpio is more low-level than I2C whatnot, and may benefit from some low-level info.
Anyway, I tried my Pico board just now with a 68K external resistor pullup. My cheap multimeter reports 3V3 = 3.24V and the pullup R makes it 0.84V on the input pin. Which makes the pulldown about 24K. But the DS reports a R(PU) R(PD) mix-max of 50K-80K. Hmmm... how many sigma is that min-max? Good documentation can help users to avoid tripping here and there. Well, being a Pico newbie, I'm not expecting the sun or the moon from the RPi folks -- I'm just trying to get a more precise mental model of this chip I am using.
Statistics: Posted by katak255 — Mon Apr 08, 2024 1:45 am
