Dealing with DC output as DC Bias Tee input

Projects General Guidance
1

Hello everyone!

I'm building a visible light communication project. The main idea is to use:

  • Arduino + DC source + Bias Tee + LED to modulate data and send it through LED as modulated on/off.
  • Arduino + photodetector to receive modulated data and processing to action some artifacts.

The general scheme goes like this:

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I have successfully created a demo using a signal generator instead of Arduino. I use a sine/square wave, send it to Bias Tee, add 12v and everything is working well. I got a signal raised above 0v.

Now I have to replace the signal generator with Arduino and use it as a data source. The code isn't a big deal at the moment because I'm OK with sending only pulses at the moment.

I understand that Bias Tee blocks DC current as input due to capacitor. So, I'm trying to generate an AC signal with Arduino but also, I understand that Arduino can't generate negative (or change direction) of current.

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What options do I have to generate an AC signal from Arduino to pass through Bias Tee with data?

2

Please link to "Bias Tee".

1 Like
4

There are lots of "light beam communications" projects out there.
Could be LEDs, or lasers, or floodlights - all visible light.

5

Take a look at the tone library it may do what you want for now.

6

Why an AC signal at all? A LED or laser can transmit data without a carrier frequency. A special case is IR remote control where a carrier frequency is used to allow for ambient light suppression.

Please explain why you think that you need an RF carrier with your light based transmission line.

7

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