I am very much a newcomer to electronics but have built (not designed) a couple of larger systems (2x25W Class A stereo amp and a Flight Computer)
The Flight Computer (I fly sailplanes as a hobby) have aspired me to get more knowledge of it all, i2c/ sensor data and input/output possibilities.
In our sailplane we have an instrument called a electronic vario meter, it indicate vertical movement of the aircraft. Since its electrical it displays information from a VDC output, V+/V- for corresponding up/down movement. We have analouge variometer onboard that move by air pressure alone, the electric vario display same data via computed signal.
I am trying to learn how to make this display vertical movement based on sensory data. Since it respond to VDC and I have PWM-data on hand I want to convert the PWM data through a DAC in order to get VDC.
Is there a way to achieve both positive and negative VDC output from a single PWM source? I assume there is but what would be the preferred (simply) method to do so? Two PWM outputs maybe, one converting 0-127bits to -2,5-0VDC, and the other convering the remaining bits to 0-2,5V, each through its own DAC?
I have no expectations that you tell me in detail how2, that is not my intent. Pointers would however be appreciated :) I have searched converting PWM/VDC and found good information related to that topic, but none that cover my question specifically.