Hello, I’m connecting my arduino Leonardo to a pi. I’m a little confused on the pin voltage tolerates. My question would be do I really need to put in a level shifting from the pi to the Leonardo if I’m powering the Leonardo to 3.3v?
What do you mean by this ?
The Pi outputs 3.3V from its pins
The Leo input pins will tolerate up to 5V so no level shifter needed to be safe in this direction
However, there is a chance that 3.3V input may not provide the voltage required to be regarded as HIGH, although in practice it is usually OK
The problem is going in the other direction because the Leo outputs 5V and that may damage the Pi 3.3V input pins so a voltage shifter is needed
my Plan is to remove the 5v voltage regulator and just run everything off of 3.3v.
Hello, I have a question if I’m powering up my Leonardo to 3.3v instead of 5v and taking out the voltage regulator. Would I need to do any programming to make it work on the 3.3v?
Joseph
This is presumably related to your other topic relating to interfacing the Leo with a Pi
Will the Leo even work at 3.3V ?
As to program changes, if you use analogRead() (if it works) you will need to take account of the different voltage range being used
Why not simply power the Leo as intended and use voltage level sifters between the Leo and the Pi ?
Hello UKHeliBob, Yes this is connected to the other one. I can use voltage shifers But I do not have any. I can remove the voltage regulator then run everything off of 3.3v. I try to order some online and it told me I will not get any into Tuesday. If I order from Aliexpress that will take 2 to 4 weeks to get in. If I order from Ebay it shows I will get it by next Wednesday. I need to try to get this to work on 3.3v. But as for the programming goes. Would I need to change anything?
Topics merged
That's great I was getting confused as well. Sorry LOL
For lowcurrent applications such as serial links you can use resistors to create the voltage shifter
What values of resistors do you have available, if any ?
As we don't know what you are trying to do it is impossible to provide advice on programming.
Have you actually got a Leo running on 3.3V ?
Oh wait a minute I found a local place that has level shifters i found online search. They are 25 minutes walk from here. Sense I don't drive I should be okay. Let me go and take a look then I can report back.
Using voltage shifters is much more sensible that trying to run the Leo on 3.3V
I understand, I was just trying to Do a wrose case scenario If I couldn't get the level shifters.
Be back shortly for an update. Thank you.
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