Is 10 bits (1024 steps) not enough? 12 bits places a lot more effort on you rpart to get everything just right.IF 10 bits is enough than some of these:https://www.sparkfun.com/products/8636Along with your analog inputs should work.You can also google 12 bit ADC SPI
That is why they have a thing called a voltage divider.
DG408 into resistor divider into MCP3201.
voltage divider going from 5 to 15 V down to 0 to 5 V means there will be roughly three times less 1/3 less usable information detectable in the output signal
Quote from: KeithRB on Oct 10, 2012, 05:28 pmThat is why they have a thing called a voltage divider.That's possible of course, but precision is potentially going to take a big hit even before the resolution of the ADC is factored in. From the perspective of the signal's information content a voltage divider going from 5 to 15 V down to 0 to 5 V means there will be roughly three times less usable information detectable in the output signal. For some applications that's not a problem, for others it will be. Instead, I would check to see if there is an affordable ADC chip/module that can handle the orignal input voltage and output serial communication of some sort at 5 VDC.
Hi All, I'm trying to finish off a project I started a while ago but I've been having a bit of trouble with the Analog Inputs...What I'm trying to do...I need to be able to read the voltage of 16 individual inputs with a reasonable level of precision (12bit, maybe?). Input voltages could be anything between 5VDC and 15VDC.Can anyone provide any suggestions on a way to do something like this?Any help would be greatly appreciated.Thanks Guys,Alex
Assuming that you are not in the noise, which you shouldn't be if you choose the divider correctly, 4196 steps at 5 V gives you the same resolution as 4196 steps at 15 volts, you are not losing anything.
Quotevoltage divider going from 5 to 15 V down to 0 to 5 V means there will be roughly three times less 1/3 less usable information detectable in the output signalso change the Vref as required to increase the effective available information by providing a Vref suitable to the measurements.
I suspect you will have a very hard time trying to find, if any indeed exist, any ADC chips that allow input signal voltages to be higher then it's Vcc voltage (or lower then Vdd), which in most cases I'm aware of is limited to standard Vcc values of 5 vdc or lower. And any ADC type module that can handle that high of input voltages would just be using some kind of programmable front end attenuator (voltage divider) and still process the ADC conversion at standard Vcc values.