Wireless Retrofit

Has anyone done a wireless retrofit for all the wiring in an old car? For example, a controller and just the 12 volt wire and sensors and instruments that operate on WiFi or Bluetooth.

Everything is generally integrated in the radio "head unit". You just need power, speakers and an antenna.
Possibly a wired in reversing camera, as an option with some.

The only common "wireless" technology other than the radio antenna, is Bluetooth hands free, either as part of the head unit or as an add-on if the existing head unit has the facility for an external bluetooth module.

Newer vehicles use CAN bus for a lot of control and monitoring, but that's a wired network.

In some that does interlink with the radio etc. for integration between different systems; eg. my Mondeo has a combined Bluetooth and voice control system in a module that connects mainly to the radio, but also the rest of the system via CAN.

Danwvw said:

Has anyone done a wireless retrofit for all the wiring in an old car? For example, a controller and just the 12 volt wire and sensors and instruments that operate on WiFi or Bluetooth.

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Maybe a bit dangerous.... Although 100% better than yesteryear wifi still suffers drop out.. Home automation is one thing, but the safety aspect alone would be a challenge..

Danwvw said:

Has anyone done a wireless retrofit for all the wiring in an old car? For example, a controller and just the 12 volt wire and sensors and instruments that operate on WiFi or Bluetooth.

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Sounds a REALLY bad idea, replace something simple and reliable with something complicated and likely to be FAR more troublesome.

I agree, it's a bad idea.

Ah... Reading again & seeing the other comments, I took is as "entertainment wireless" retrofit, as actually using radio interconnect between different parts of the vehicle controls is just infeasible...

CAN was originally created by Bosch and others to perform that function - a simple two wire data bus plus power and you can attach as many local sensor and controller devices as you wish, anywhere around the vehicle.

Most vehicles now have more than one CAN bus, eg. one for bodywork fittings, one for dashboard controls, one for engine & fuel or whatever.

You can get both "dumb" CAN peripheral ICs and MCUs that have CAN built in, just needing an 8 pin bus driver IC attaching.

Actually I think it would be a great Idea! Especially if components could be replicated to fit original. Now with the price of Copper wire going so high, wiring harness have to be specific to a car and are often unavailable or several hundred dollars for poor quality non original color and undersized wire.
The electronics could be universal, instruments 3d printed or something?
There could just 12 volt wires maybe a signal wire or coax if needed but why not just use a coax for the 12 volt and signal on low current instruments etc...The only big wire needed would be battery cables and the generator-starter. Lights could be lower current LED Technology.
Perhaps displays that are universal that fit in model specific panels with applications to look like the original instrument cluster.
Yes: Can!

Danwvw said:

Actually I think it would be a great Idea! Especially if components could be replicated to fit original. Now with the price of Copper wire going so high, wiring harness have to be specific to a car and are often unavailable or several hundred dollars for poor quality non original color and undersized wire.
The electronics could be universal, instruments 3d printed or something?
There could just 12 volt wires maybe a signal wire or coax if needed but why not just use a coax for the 12 volt and signal on low current instruments etc...The only big wire needed would be battery cables and the generator-starter. Lights could be lower current LED Technology.
Perhaps displays that are universal that fit in model specific panels with applications to look like the original instrument cluster.
Yes: Can!

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Sorry, silly idea all round - and the cost of copper wire is far lower than radio modules and much more reliable and efficient - in any case you'd still need the thick copper wire to carry the power.

Creating instruments is a reasonable scenario, and often done - but simply connected to the existing electrics.

Yes for sure It's a silly Idea. Just like owning a 60's car! There are some turn key boxes that maybe are not wireless though but could be but they are in the $2000 range. They have channels for sensors and it takes a controller something different for outputs. Then there are some cheap Temperature interfaces and some bluetooth stuff that work with Smartphones for displays. It would be nice though, could have a Wide Band receiver for air/fuel ratio and Cylinder Head Temperature readout too.

If you want to make something that's really inferior to existing car electrics, then feel free - as long as you're sure it's going to be legal?, which rather depends on where you are.

Danwvw said:

There could just 12 volt wires maybe a signal wire or coax if needed

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You have just re-invented the CAN concept, Dan!

That is exactly what you have with that, 12V power and a thin data bus connection through dozens of different devices.



It's even brought out to the OBDII diagnostic sockets, on vehicles that support that setup:

Only 1/2 a Meter? I guess that's twisted pair from the coax. The coax could probably be plenty long. Oh I see it's 40 meters. I am just wondering, what it takes to interface to it for example input and output devices.

Danwvw said:

Only 1/2 a Meter? I guess that's twisted pair from the coax. The coax could probably be plenty long. Oh I see it's 40 meters. I am just wondering, what it takes to interface to it for example input and output devices.

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A number of PIC's include CAN interfacers, no doubt there are application notes at MicroChip.

No coax, it's a just a loosely twisted pair of wires for moderate distances such as within vehicles, thought it may be shielded for industrial applications between different pieces of equipment.

You can get single chip "dumb" i/o expanders with configurable digital and analog / pwm inputs and outputs, eg.

A lot of the higher end PIC MCUs have CAN included, I've used it in some of my designs.
They can work as controllers, peripherals or both,

There is also a CAN controller that works as an SPI peripheral, with PICs or such as Raspberry Pi etc.


The basic idea of a simple CAN system is that every device broadcasts it's readings or whatever, with the unit address saying what that reading relates to - temperature, engine revs, throttle position or whatever.

Any other device that needs any info from any specific sensor just listens for packets from the appropriate addresses.
The CAN interface has facilities for "masks" that allow groups of addresses to be ignored so devices don't have to process irrelevant data.

And of course command data can be sent to specific addresses.