I’ve been using an Arduino Uno and I just ordered a few Xiao. I am trying to figure out which components I can use so I can order those, as well.
Am I correct in assuming if it says 3.3v~5v, that means it can run on 3.3v but can handle being plugged into a 5v pin?
Also, I have been looking at rotary encoders. They all are listed at 5v. I am getting conflicting and partial information about how to make this work. Perhaps I am blind, but also no practical examples. One source says they work just fine and mentions handling the voltage through code. Another mentions pull up resistors. Can a rotary encoder work with a Seeeduino Xiao? If so, what avenues should I investigate to make it work.
I have googled and googled and perhaps I am just clueless, but I am not finding many resources for this particular board. Any guidance would be appreciated.
Yes
The Xiao has a 5v supply pin
To add to Bill-Richard’s answer, it’s worth noting that the circuit diagram for the XIAO includes a diode on the 5v pin with a max rating that effectively limits you to ~ 500ma. That’s far more than you’ll need for most sensors. (Some older posts on the forum suggest the diode may have been omitted in production, but I leave testing that and frying your stuff up to you.)
The datasheet on the voltage regulator used on the 3.3v pin says it’s got a max current rating ~200ma, which again should be far more than you’ll ever need for most sensors.
Driving LEDs or servos (including servo rotation sensors) or relays off of these pins will definitely hit these limitations quickly.
Assuming these are mechanical encoders like the common KY-040 style devices:
Do NOT connect the rotary encoder 5V pin to 5 Volts!
This is connected to pullup resistors to the data and clock (and switch if the encoder has one). You do NOT want the signals to the CPU to go up to 5 Volts. Connect it to 3.3V
If this doesn’t help, post the Specification/DataSheet for your encoders.
Regards,
Dave
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Thank you for the response!
I appreciate your response!
Yes, it is a Ky-040, I think. It came in some kit I ordered which had no data sheet.
I ended up going with buttons, which was okay because it was a learning experience, too. I don’t want to waste anyone else’s time with a problem I am not currently trying to solve though. I will, however, keep everyone’s feedback in mind!
Thank you for the response!
Sorry if this is a dumb follow-up question, but why does the XIAO have a 5v pin if it can only support 3.3v sensors?
