Level Converted CAN-BUS Module

Introduction

There are many CAN-Bus modules available for purchase to the DIY Electronics Enthusiast and the Maker community. Our Level Converted CAN-BUS module is different. Where the standard modules are all 5v devices, ours are level converted, allowing you to interface it with 3v and 5v microcontrollers, the choice is yours…

Level converted CAN-Bus Module

Level Converted CAN-BUS Module together with standard CAN-BUS breakout for comparison.

The Schematic

How does it work? / How do I use it?

The Level Converted CAN-BUS Module is based on the MCP2515 CAN Controller from Microchip, with the TJA1050 CAN Tranceiver used for communicating with the CAN-Bus. These two chips are extremely cheap and easy to get hold of, but they are also one of the main reasons for the redesign of the module. While the MCP2515 is useable with a voltage range of 2.5v to 5v, the TJA1050 is not. When using the commercially available CAN-Bus modules, this limits you to using 5v microcontrollers, or for the more informed, using level converters in-between to translate back and forth to the desired logic levels.The MCP2515 is an SPI device, and in my opinion, having long wires on an SPI bus is not always the best way of doing things, due to ringing and other undesirable interference. Having to add a level converter module into this already questionable setup, can add a lot of other undesirable effects. I have thus decided to design and manufacture my own module, with 5 level converters directly on the PCB, thus reducing the length of connecting wires, as well as reducing complexity.Using the device is now as easy as providing a 5v voltage source, as well as an additional 3v source if you need the level converters, and connecting your microcontroller to the appropriately marked logic side of the module. A jumper at H1 can be set/unset to enable the 120ohm ballast resistor that is needed on the CAN-Bus for very short distance connections. Example connection to an Arduino

Use the 5v logic side, and power the module with 5v and ground. You do not need a 3v power source.Connect the pins as follows:CS pin to Arduino Pin 10SO to the MISO pin on the Arduino Pin 12SI to the MOSI pin on the Arduino, Pin 11SCK to the SCK pin on the Arduino, Pin 13INT to an interrupt capable pin on the Arduino, usually pin 2 or 3

Example connection to an ESP32 module

Provide a 5v as well as 3v power source with a common ground connection.Connect your logic to the 3v logic side of the PCB Module.

CS pin to GPIO2SO to the MISO pin, GPIO19SI to the MOSI pin, GPIO23SCK to the SCK pin, GPIO18INT to an interrupt capable pin on the ESP32

Where can I get my own version of this module?

This module will be exclusively available from PCBWay for the foreseeable future. Click on this link to order your own, and help support a great company that produces very high-quality PCBs for a very affordable price.

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