![op amp offset voltage with gain op amp offset voltage with gain](https://s2.studylib.net/store/data/011757239_1-f223cc6e50c8f207a5493b2f32c52718.png)
The operational amplifier circuits described below will allow you to perform this "signal conditioning". However using a difference amplifier (see below) we can take the 3.4 - 3.6, SUBTRACT 3.2, and multiply by ten - giving a nicely measureable signal in the range 2 - 4 Volts. Suppose the signal is changing between 3.4 and 3.6V - so a change of 0.2V we could amplify it by ten - but then it would be changing between 34V and 36V - still no good. So if the signal is changing between 0.1 and 0.2V an amplifier with a gain of 20 will give a signal in the range 2 - 4v which matches the measurement range of the Arduino. An inverting amplifier will let you produce a positive voltage of the same value, which you can then measure.Īlso your signal may be too small to measure (green line) in which case a non-inverting amplifier as described below can help. So if your signal is outside this range - as the orange and blue lines on this diagram - you cant measure it directly. (other ranges are available on different versions) The Arduino Uno has ADC inputs that can measure voltages in the range 0 to 5V. However these simple devices can be used in combination to create many useful circuits - even very powerful ANALOG computers! If you want to measure a signal voltage with an Arduino, you may face some of the issues described here often a simple circuit using an operational amplifier can help. Operational amplifiers are simply devices that amplify the difference between two inputs.
![op amp offset voltage with gain op amp offset voltage with gain](https://wiki.analog.com/_media/university/courses/electronics/text/chptr3-f7.png)
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Introduction: measuring voltages with an Arduino