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Can a VGA output be used to output an analog signal?

I'm using an FPGA to program and control the VGA output.

I want to use it as a DAC to control an external circuit (I'll be doing PID control). Could I just stick individual wires into ports corresponding to certain colors and program those colors accordingly or is there a better/more efficient method?

My board is the Basys 3.

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    \$\begingroup\$ this is an XY problem ... you are asking about what you believe to be a solution to an unspecified problem ... instead, you should be asking a question about the actual problem that you are trying to solve \$\endgroup\$
    – jsotola
    Commented Jun 12, 2020 at 20:52
  • \$\begingroup\$ No I asked if a VGA could be used as a DAC. The question was general as is the problem and the answer was clear. I got a clear answer about the solution I wanted. I wasn't asking for a solution to the underlying problem. I now know what to expect if I choose this solution.... \$\endgroup\$
    – Andrew
    Commented Jun 12, 2020 at 22:04

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For a better quality of producing RGB signals you could use 4,5 or 6 digital signal (FPGA pins) and use a resistor-network (as a DAC). Take a look at this schematic which is used in an FPGA evaluation board (ALINX-AX309) and check out how it produces the VGA signals: https://github.com/alinxalinx/AX309/tree/master/SCH

And you can also produce an analog signal with PWM. It can be implemented by a counter and a comparator in FPGA. Then filter the output PWM signal simply by a RC filter to obtain a smooth analog signal.

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