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The battery voltage detected with ADS1115 is not in Volt ? - Printable Version

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The battery voltage detected with ADS1115 is not in Volt ? - kste - 2017-03-13

The measured voltage batteries through ADS1115 on SignalK is in mV.
And 'normal or to have it in volts needed to set something?


RE: The battery voltage detected with ADS1115 is not in Volt ? - e-sailing - 2017-03-13

You can use the adjustment for the mcp3008.
Go to tab "SPI sensors"
Select channel 0
Click value setting (the default for ads1115 should be 0 0 and 33000 xxxx)
now you can enter the measured values for some points.
The result (inserted points) can be shown in a "graph"
Open openplotter.conf in an editor, go to section SPI, copy the line value_0 = [...
into your openplotter_analog.conf section ADS1115_X adjust_points = [... (you have to rename value_0 to adjust_points)
It should look like "adjust_points = [[0.0,0.0],[3525.0,8.01],[4501.0,9.89],[5483.0,12.0],[6520.0,14.2],[33000.0,50.0]]" ([adc value,real value])

With this way you can measure formed tanks very well because the tank level isn't linear. The curv can be split in short lines.
Best is to use the Si unit for the real value. The Si units of SignalK can be found opening "diagnostic SignalK input", button "Unit Setting".


RE: The battery voltage detected with ADS1115 is not in Volt ? - kste - 2017-03-13

OK good!
Thanks e-sailing.

It just seems that the measure with ADS1115 is imprecise...
(I put a divider with precision resistors and a trimmer for calibration)