Rena
Active member
As I understand, the analog inputs on Teensy 3.2 are rated for 3.3V maximum and can't handle a 5V input. In my project I want to defend against accidentally connecting a 5V source.
I've found this circuit, but the comments suggest it's not safe. However it seems like the concern is mainly with long-term use and causing glitches. I'm not too concerned if the Teensy malfunctions when someone connects 5V, so long as it doesn't fry. (Even better if the circuit can be modified to eg light an LED to tell them to disconnect that ASAP!)
Is that design suitable for protecting from short overvoltage spikes? Or can anyone suggest a better method, that doesn't compromise the accuracy of in-range signals?
Even better if it could be adjusted, so that I could eg turn a knob to scale the input down to 3.3V and still be able to analyze a 5V signal that way, without risk of blowing things up.
I've found this circuit, but the comments suggest it's not safe. However it seems like the concern is mainly with long-term use and causing glitches. I'm not too concerned if the Teensy malfunctions when someone connects 5V, so long as it doesn't fry. (Even better if the circuit can be modified to eg light an LED to tell them to disconnect that ASAP!)
Is that design suitable for protecting from short overvoltage spikes? Or can anyone suggest a better method, that doesn't compromise the accuracy of in-range signals?
Even better if it could be adjusted, so that I could eg turn a knob to scale the input down to 3.3V and still be able to analyze a 5V signal that way, without risk of blowing things up.