Transmit a signal over a wire far away.

I need to transmit a signal from an arduino board to a LED strip that is 100m away at a speed of Mbps. How can I do that? The LED strip would be similar to this one: Thanks in advance.

RS485 or ethernet ?

And how can I use ethernet or RS485 if my arduino does not have any port for them?

RS-485 only needs a serial port and a transceiver, you have the serial port and can buy a transceiver shield.

Ethernet only needs an SPI port and a WS5100 (or similar) interface chip, you have the SPI port and can buy an Ethernet shield with the interface chip.

Personally I would go for RS-485, I think it will be easier to set up as it's just simple async serial comms.


Graynomad: Personally I would go for RS-485, I think it will be easier to set up as it's just simple async serial comms.

Absolutely. Ethernet would be overkill here.

tuket: And how can I use ethernet or RS485 if my arduino does not have any port for them?

Usually I'm the last to throw out the "google it" response, but really... :-) You're going to have to put some effort into this... Searching for "arduino rs485" yielded a post on this forum as link #1, and SparkFun's shield as link #2.

Open air wireless is an option too... there's some transmitters around - nrf come to mind.

Thanks for the replies. I need to stress in he fact that I must use only one arduino board and that I need to change from low to high in 0.7 us, do you really think that the speed of the rs-485 is enough to transmit to that speed when the other end is at 100m? I have read that "a 50 meter cable should not signal faster than 2 Mbit/s". It is true that I could use another arduino board to receive the signal and to control the led strip but that would increase the cost.

The Pololu LED strip uses signals with 2.5 microsecond bit time, which is 400 kilobits/sec You could always just try with 100 m of cable and see if it works.

RS485: The RS-485/RS-422 standard covers line lengths up to 4000 feet.

The driver slew rates of the MAX481, MAX485, MAX490, MAX491, and MAX1487 are not limited, allowing them to transmit up to 2.5Mbps.

Pololu looks like it is using this chip
Uses different length highs & lows to make 0s and 1s, then low for a certain time period is used to indicate “no more data, update the output”.
Passing that along via RS484 transmitter to RS485 recevier would work fine.

WS2811-preliminary.pdf (320 KB)


I'm offering some of my expertly manufactured wireless cables on ebay. They work perfectly well without any Arduino shield.

The wireless cables consists for the most part of nitrogen (78%). The other 22% are separated in pure oxygen and noble gases. It's award winning low amount of carbon dioxide (only 0.03612%) is also worth mentioning and offers very high transfer rate (tested up to 1.0 GHz).

The cable could be used for almost all data connections up to a maximum length of 100m (328ft). Due to it's great flexibility it could be installed in only a few seconds.

I use the cables a lot to connect temperatur sensors around my house.

-(CBR) PS: With the new enhanced version you could transmit power, too. (up to 15W max.)

How do you transmit 15W wirelessly? You beaming microwave energy around the house or something?

Snork. I have a petition to ban the dangerous chemical Dihydrogen Monoxide for you to sign, once you are done ordering some of CaptBlaubaer's wireless cable.

@CrossRoads: I can't disclose detailed information about the technology the wireless power cable uses at the moment, because the patent is still pending. Just a hint, it is one of the first commercial products using the Brout-Englert-Higgs mechanism transmitting bosons in a well defined Higgs field.

I am intrigued by your ideas and would like to subscribe to your newsletter.

Where would we look to find these useful cables on eb*y?
But why are they tested only to 1GHz? My preferred applications involve transmissions between about 3x1014 and 9x1014 Hz.

petition to ban the dangerous chemical Dihydrogen Monoxide

Where do I sign, that's dangerous stuff.


Do no trust them. Higgs and Boson owe me money.

Whoa, Dihydrogen Monoxide is really dangerous stuff.

IT MUST BE BANNED!!!!!!!!!!!!!!!!

Found on wiki:

Dihydrogen monoxide: is called "hydroxyl acid", the substance is the major component of acid rain. contributes to the "greenhouse effect". may cause severe burns. is fatal if inhaled. contributes to the erosion of our natural landscape. accelerates corrosion and rusting of many metals. may cause electrical failures and decreased effectiveness of automobile brakes. has been found in excised tumors of terminal cancer patients.

Despite the danger, dihydrogen monoxide is often used: as an industrial solvent and coolant. in nuclear power plants. in the production of Styrofoam. as a fire retardant. in many forms of cruel animal research. in the distribution of pesticides. Even after washing, produce remains contaminated by this chemical. as an additive in certain "junk-foods" and other food products.

Thanks for the answers!