Colin O’Flynn of NewAE designed this simple CAN to 3.3V logic level interface:

CANoodler

CANoodler is a simple CAN (not CAN-FD) interface, which provides logic-level 3.3V output. It’s designed to be used with microcontrollers that have CAN blocks inside them, and in particular uses a pinout on some ChipWhisperer CW308 (UFO) Target boards.

It’s kinda nice (I think anyway) since it has these features:

• LEDs for TX/RX (uses MOSFET to drive LEDs so doesn’t slow your I/O pins down).
• Reverse-polarity protection on 3.3V input.
• Switch for CAN termination on/off with LED feedback.

The design files are available on GitHub:

newaetech/CANoodler

coflynn has shared the board on OSH Park:

CANoodler – CAN to TTL Interface