CAN open working on 5v not on 3.3v

Hello everyone,

I have my set up as CAN bus shield with arduino treating as master and slave to send data packets. I have successfully sent 8 bytes data from one CAN bus master to three CAN slave. This is working fine.But when i tried to change my USB power line from 5V to 3.3V, my code has no errors and also the CAN shield have their leds on but there is no communication between master and slave, so the error in sending message is dislayed.

Can anyone tell me what should be the problem and how i can troubleshoot it

The USB circuitry may not work with any voltage except 5V.

Many controllers require a reduced frequency on reduced voltage, e.g. Pro Mini 16MHz@5V but only 8MHz@3.3V.

So it’s a rather stupid idea to reduce the USB voltage to 3.3V. For a more detailed diagnosis more information is required, like links to the data sheets of all components, a circuit diagram…

Hi, Welcome to the forum.

Please read the first post in any forum entitled how to use this forum. http://forum.arduino.cc/index.php/topic,148850.0.html .

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

  • What model Arduino are you using?
  • How are you lowering your USB to 3.3V?
  • Where are you applying the 3.3V?
  • Can you post link to CAN shields please?

Thanks.. Tom.. :)

Hello @TomGeorge,

  1. The arduino model am using is https://store.arduino.cc/usa/arduino-uno-smd-rev3

  2. The method am using to reduce my voltage is 3.3V Conversion | Arduino Tips, Tricks, and Techniques | Adafruit Learning System

  3. The CAN shield am using is http://wiki.seeedstudio.com/CAN-BUS_Shield_V2.0/#hardware-overview

There are so many questions, a circuit diagram including all power supplies is required.