I followed a tutorial on 8-bic DACs using an R-2R resistor ladder. I am outputting a sine-wave using data from 0 to 255 on pins 0-7. This goes through the pins into the R-2R DAC producing an analogue signal.
Now I would like to convert this signal into something that can be used by a piezo speaker. I understand (perhaps incorrectly) that the speaker cannot play this signal because it needs an AC signal, whereas the DAC output is 0 to +5V.
I've read that now I need to "bias" the DAC to electrically subtract 2.5v from the output to make it -2.5 to +2.5 volts. This signal should then be able to be fed into the speaker. Is this correct? How do I bias this signal, with a capacitor in series?