https://www.raspberrypi.org/documentati ... /README.mdBlastFX wrote: ↑Thu Jul 11, 2019 3:44 pmToo bad, I was hoping to interface the GPIO to a TTL level device with only series resistors.
Although the page you linked says that sinking up to 500 μA into the “diodes” is fine (despite saying sinking any current into them is not acceptable just a paragraph earlier), I'm not risking my brand new Pi 4 to test that assertion.
Guess I'll squeeze a proper level shifter in somehow.
On a side note, isn't it a bit weird that the RPF supports, nay, encourages interfacing the Pi with other hardware, but refuses to provide proper electrical specification of the GPIO?
I've read that page (as well as thejamesh wrote: ↑Thu Jul 11, 2019 3:50 pmhttps://www.raspberrypi.org/documentati ... /README.md
It's still valid for Pi4, AFAIK, and all I have I am afraid. Seems to be enough for the majority of projects out there.BlastFX wrote: ↑Thu Jul 11, 2019 4:46 pmI've read that page (as well as thejamesh wrote: ↑Thu Jul 11, 2019 3:50 pmhttps://www.raspberrypi.org/documentati ... /README.md
registry maps“datasheets” for all 5 generations of the SoC and the specs of Compute Module 3).
First off, it's for the BCM2835. I can't know whether it still applies 4 generations later, especially after a major revision.
Second, it doesn't contain the information I was asking for (which has been present in pretty much every datasheet I've ever seen; most even include a diagram of the output driver).
That's good to know.
Yup, that's what I was thinking of, FETs with pull-up resistors. If I go for SOT23 FETs and 0603 resistors, with a bit of luck, I should be able to squeeze it in. If that doesn't work, I'll look for a dedicated chip in a small package (SSOP or QFN).