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10 years, 10 months ago.
11u24 Analog In Negative
Hey everyone , I just wanted to know . According to the handbook v in can only measure 0 to 3.3v so I guess this means I can't read negative values . Problem is I really need to do that in my project . What should I do ? Buy an external ADC ? Is there any way to bypass this or something .
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You can make a level shifter with for example an opamp, or just a capacitor + two resistors can work if you have for example a sine wave. It depends on your setup. But in the end you need to have it between 0 and 3.3V on your mbed.
posted by Erik - 23 Jan 2014Thats a problem because I am comparing two signals with various techniques and at some points the signals must go negative , if I shifted them up the result would change .
posted by Antreas Antoniou 23 Jan 2014If you shift them up with a fixed value you can easily correct for it in software again. But what is better really depends on the specific situation.
posted by Erik - 23 Jan 2014that's correct . What is the most accurate way to level shift an analog signal say 3 volts ? I need it to be at least 97% accurate
posted by Antreas Antoniou 23 Jan 2014