Imported from GitHub: LoganCarter08/Open_CAN_Bus_Hub · commit c6aa3e3 · license MIT

Description

An open source alternative to a CAN bus hub primarily used in aftermarket automotive industry.

README

Open CAN Bus Hub

An open source alternative to a CAN bus hub primarily used in aftermarket automotive industry.

This project is migrating to Codeberg to avoid some changes being made by Microsoft. Future updates will be here.

Overview

This project is intended to reduce the cost of a simple part needed for many project cars. If you are building a car and need to add aftermarket equipment via CAN bus you will likely need a hub of some sort to distribute the network to each of your devices.

The existing products like AEM, Haltech, and CANChecked are very expensive, are limited to a few devices after connecting the ECU, and often require external resistor termination. This project addresses these issues.

This project will walk you through building your own CAN bus hub to meet your needs.

Design Notes

• The industry standard for automotive CAN bus has become DTM plugs, so utilizing these was a priority
• Minimizing the number of wires to keep complexity and risk of issues was the primary priority. Later versions may attempt to eliminate the need for any wires regardless of number of rows.
• Handling high(ish) current was something we regarded as important as users may be powering many devices from one hub. See the important section for more info on power capabilities.

IMPORTANT

• Do not exceed 10 amps total on the hub unless you custom order heavier than 2oz copper on the board. This means all of your plugs combined should not exceed 10 amps. It would be ideal to put a fuse prior to the hub to ensure this is not exceeded. Read the PCB readme for more information on amperage.
• Do not exceed 7 amps total on each of the plugs unless you custom order heavier than 2oz copper on the board. The DTM pins are only capable of 7 amps and so is the PCB. Read the PCB readme for more information on amperage.
• This design does not support the DTM waterproof gasket that comes with standard DTM plugs. This is partly due to the high cost of the gasket ($4 each) and partly due to the added complexity for 3D printing. Due to this is it not recommended to use this design in an area that will see direct contact with water or particulates that can cause electrical problems.

Tools Needed

Note: All Amazon links below are just to serve as an example of what you are looking for. These can be substituted with any equivalent tool.

Tool	Details	Link
Soldering Iron	Any will do, but a pointed tip is helpful	https://amzn.to/42WFt6c
3D Printer	Read the FAQ if you do not have one.
Allen Keys	They'll often send some with bolts.	https://amzn.to/4j0mix5
Needle Nose Pliars	These are not required, but make assembly easier.	https://amzn.to/3GLlzma
Wire Strippers	Only needed if doing more than one row.	https://amzn.to/4kl7wSS

Parts Needed

Note: All Amazon links below are just to serve as an example of what you are looking for. These can be substituted with any equivalent part.

Part	Details	Link
Solder	Pretty much any basic solder for electronics should work well.	https://amzn.to/4mdSlfK
Filament	I recommend ASA	https://amzn.to/44zXtVi
DTM Pins	PN: 0460-202-20141	https://www.te.com/en/product-0460-202-20141.html
M2 Bolts	M2x4mm socket cap	https://amzn.to/3GLZ6FB
M3 Bolts	M3x12mm flat cap	https://amzn.to/3GRSxkQ
M2 Threaded Inserts	M2x3.2mmx4mm	https://amzn.to/4m9bsb3
M3 Threaded Inserts	M3x5mmx4mm	https://amzn.to/3EYypgh
120ohm Resistor	1/4 watt	https://amzn.to/42SdeFQ
PCBs	View PCB readme for more info on ordering	https://www.pcbway.com/project/shareproject/Open_CAN_Bus_Hub_V1_0_372ae918.html
Wire	Only needed if doing more than 1 row. Size according to your power needs.

Build/Assemble

1. Follow the instructions in the Model readme for how to make and assemble the case for the hub that houses everything.
2. Follow the instructions in the PCB readme for how to order and assemble the PCBs.
3. If you are adding a termination resistor, solder it into the PCB that needs it. It is recommended to add it to the last PCB in the hub, furthest from the ECU. Make sure to snip the excess leads flush with the PCB to ensure good fitment into the printed piece and no chances of shorting.
4. Solder the pads between each PCB. This means each pad should be soldered to the corresponding pad on the adjacent PCBs. If you are having a hard time getting your solder to bridge the gap it may be helpful to put a piece of wire without insulation between the boards or even a single strand from a multi strand wire.
5. Repeat step 11 for every row in your box.
6. If you have more than 1 row you will need to connect each row with wires here. Make sure to keep the wires as short as possible as any excess will make bolting the bottom half on more difficult. If you need your box to handle higher amperages it is recommended to solder your power and ground wires to the through holes next to the corresponding pads. These will likely provide a better solder point for thicker wires and be more reliable.
7. Using the M3 bolts bolt the bottom half of the hub to the top half.
8. Install into the car and plug in all of your devices!

FAQ

Q. How much does it cost to build?

A. This will depend on how many plugs you need, but a quick breakdown might look like the following. All prices are in USD and estimates based on my purchases. This assumes you have all tools.

Part	Cost Estimate Each	Quantity
Pins	$0.15 - $0.24	4 per plug
PCB	$0.54 - $5.4	1 per plug
Filament	$0.30 - $0.50	1 per plug
M2 Bolts	$0.08	min of 2 per plug
M3 Bolts	$0.17	min of 4
M2 Threaded Inserts	$0.06	min of 2 per plug
M3 Threaded Inserts	$0.09	min of 4

Note: The more PCB you order the cheaper they are. Example: A 10 plug hub should cost around $40 if you only bought 10 PCBs. A 20 plug hub should cost around $50 if you only bought 20 PCBs.

Q. What pin orientation is used?

A. The intended orientation is what Link ECU uses, but should also work with Haltech and others. You may notice that in both versions pins 1 and 2 are power and ground and pins 3 and 4 are CAN low and CAN high. Power and ground pins can be interchanged and so can the CAN low and high as long as every device that is plugged into this hub follows this standard. If this isn't clear just think of the markings on the PCB as CAN 1 and CAN 2. They don't actually care if they are high or low. They are just marked to make it easier for assembly. Same with power and ground. These are sized the same internally, so you could use the power pin as the ground and vice versa if you need to for your application.

Link's orientation:

Haltech's orientation (wire side):

Q. I only need x number of PCBs and it is more expensive to order small amounts.

A. If you are in the US feel free to contact me. I might have some available and if not I may do a bulk order, depending on interest, to lower the cost per individuals. I can do the same with the pins and resistors too. Shipping outside of the US will likely be more expensive than you ordering them from a manufacturer directly.

Q. Can I sell these?

A. I put this project under an MIT license. You are free to sell them if you would like. I just ask that you add a reference back to this project so it can help people who are looking for a DIY solution.

Q. What if I don't have a 3D printer?

A. Depending on your budget or needs you can either find a 3D printing service to print it for you, look for local hobbiest with printers, check your local library for printer usage, or you can contact me if you are in the US.

Q. Do I need to know CAD?

A. CAD skills are really helpful here. The design is partially parametric, but it is missing brackets for mounting. These will likely need to change per user, so they are not included in the model. I will likely upload some STEP files with some sizes with random mount designs just to give people options. Visit the readme in the Model folder for more information.

Q. Do I need to know PCB design?

A. Not unless you need to make changes to the design or want to contribute to the project.

Disclaimers

• All Amazon links are affiliate links.
• The PCBWay page for the PCB does give me some money for each order placed.