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Topic: AtoD converters on an ATMEGA 168  (Read 177 times) previous topic - next topic


I am designing a device that can monitor cells in a Lithium battery pack.
I was going to use an ads1115 16 bit converter but I think the onboard AD converters will be accurate enough for the job, I will need to convert 6 voltages and have the I2C bus on the ATMEGA 168 I believe this is possible what I am not so sure on is how consistent the onboard AD converters are for a given voltage, over time and temperature how much will the output numbers change. the worst resolution I will be dealing with will be about 0.05v this will be fine for measuring the voltage in LiPo cells  a lot think that 3 DP are required but frankly only 1 is.
so my question is how much will an on board AD converter fluctuate.


Look at the datasheet for the ATMEGA 168  section Analog-to-Digital Converter to see details of the accuracy and resolution. The voltage reference is either dependent on the supply voltage or an internal voltage reference which you have to calibrate. Since it is a 10bit ADC, 1023 is the full scale. With a 5 volts as the reference, that represents units of approximately 5 millivolts.

Are these 6 cells wired in series and are you able to take them out of circuit (somehow) to measure their individual voltages in isolation or how are you intending to perform measurements ?

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