Hello Gurus,
Hope you are all safe and well.
The scenario…
* PICAXE running at 3.3V supply.
* Separate peripheral with a digital output 5V
Is it going to be a problem (damaging to the PICAXE) to connect ANY external device/IC with a digital output of 0v (LOW), 5v (HIGH) directly to a PICAXE input when the PICAXE has a supply voltage of 3.3v?
This question comes because the datasheets indicate I/O pin input threshold to be VCC +0.3v. However, as we all know PICAXE IC’s are 5v compatible.
My thoughts is that I don’t expect it to be a problem other than if a READADC was performed, in which case I would expect to see 255 returned until the input voltage dropped below 3.3v. Otherwise 5V input to a pin would simply return a 1 or HIGH without issue.
What do the Guru’s say/think?
As always, thanks in advance guys/gals.
P.S. Hippy: A personal thank you to all your assistance and contributions over quite a few years. You are highly respected. Best of luck in all your future endeavours friend.
Regards,
Mort.
Hope you are all safe and well.
The scenario…
* PICAXE running at 3.3V supply.
* Separate peripheral with a digital output 5V
Is it going to be a problem (damaging to the PICAXE) to connect ANY external device/IC with a digital output of 0v (LOW), 5v (HIGH) directly to a PICAXE input when the PICAXE has a supply voltage of 3.3v?
This question comes because the datasheets indicate I/O pin input threshold to be VCC +0.3v. However, as we all know PICAXE IC’s are 5v compatible.
My thoughts is that I don’t expect it to be a problem other than if a READADC was performed, in which case I would expect to see 255 returned until the input voltage dropped below 3.3v. Otherwise 5V input to a pin would simply return a 1 or HIGH without issue.
What do the Guru’s say/think?
As always, thanks in advance guys/gals.
P.S. Hippy: A personal thank you to all your assistance and contributions over quite a few years. You are highly respected. Best of luck in all your future endeavours friend.
Regards,
Mort.