Does Feather M4 CAN support 3.3v CAN?

[davidthefuturist]

This might be a really dumb question, but title says all.

Per my last post, I was having problems getting my two Feather CAN M4 units to talk to one another and it seems that my problem was solved once I refreshed serial monitor as well as a few other adjustments.

Now, it seems that when I comment out the 5v booster on both the receiver and sender side, I get nothing, no communication. When I turn the boosted back on, communication seems to work again.

I measured the voltage from GND to CAN HIGH using a multimeter and got 2.9 ish volts when it was working successfully with the booster enabled.

I have a device that uses 3.3v CAN, am I unable to interface with it with the Feather if it only seems to work with 5v CAN? Does it technically not matter?

I also came across this article and I'd like to see if any of you could weigh in before I attempt connecting this to a real system to avoid burning out electronics: https://embeddeddesignblog.blogspot.com ... s.html?m=1

[adafruit_support_mike]

I have a device that uses 3.3v CAN, am I unable to interface with it with the Feather if it only seems to work with 5v CAN? Does it technically not matter?

By default, the CAN bus operates at 3.3V. There's a BOOST_ENABLE signal connected to GPIO #4 that turns on a 5V supply for the bus.

The CAN transceiver accepts any voltage higher than 70% of its supply voltage (2.3V for VCC=3.3V, and 3.5V for VCC=5V) as a HIGH input signal.