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Circuits for analog Input & Outputs

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Newbie level 2
Sep 21, 2009
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analog input circuit

Hi all, I would want to know if there is neccessary to have some kind of electric circuit after the output of an analog sensor (doesn't matter which one) to connect to an analog input of a microcontroller (some amplifier or something else)

The idea is to have a "master circuit" (circuit#1) to connect any output of a sensor to an analog input of a microcontroller, inside the microcontroller is where I would do the A/D conversion.

I have in mind that every sensor would need some specific circuit, but this would be before connecting the circuit that I'm requesting for.

I also would wanted to know if there is neccessary another circuit (circuit #2) between the analog output of the microcontroller and an actuator (doesn't matter which one), to activate any actuator of the market.

The input and the output are not related.

Thank you in advance! ;)


That depends on the sensor / actuator, are you using
"bare" (transducer element, motor winding) or are
you going to insist your user goes with a "packaged"
device with a standardized interface? Both are viable
and the decision comes down to sort of a "make/buy"
value decision on the user's behalf, by you.

If you don't have a clear decision then you have to
figure that the general answer is "yes" (need some
interface layer) at least as a contingency. Though by
some smarts and some acceptance of poorer analog
resolution (e.g. throwing away all range over a volt,
if you have a 0-1V sensor) you can handle more of
the "unconditioned" inputs/outputs, or get by with
lower cost interfaces than a perfectly-tailored
whiz-bang (like producing stepper motor wvfms on
chip and only needing high voltage driver ICs, vs
sending CW/CCW commands via a stepper motor
driver IC of perhaps higher cost). The more general
you want to be, though, the less you want to go build
in a ton of 90%-unused feature options (which will
need something to tell which ones to use, on and on).

Hi dick_, The idea is to have an specific interface before the general interface, but right now I only want to desing just the general interface. For this, we could suppose the voltage range between 0-5V is the input to the general interface.

I'm not sure if is necessary to place something (like resistors or some active components) or not.

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