AN1711 datasheet(17/40 Pages) STMICROELECTRONICS

Part #	AN1711

Description	SOFTWARE TECHNIQUES FOR COMPENSATING ST7 ADC ERRORS

PDF	40 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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SOFTWARE TECHNIQUES FOR COMPENSATING ST7 ADC ERRORS

2.4 NOISE FILTERING ALGORITHM

During ADC conversions it is possible that a small number of results are received which are to-

tally different from the majority of values. These are called outliers. These may be the result of

induced noise in the system. Outliers should be filtered so that the average result is not af-

fected by them. The flowchart shows how this algorithm works.

Figure 10. Flow chart for noise filtering

yes

range

sample = (+/-)expected

If first sample then use this value as reference for noise

filtering

Initialise ADC, variables, and select analog channel

Check

Average

yes

over

16 samples

START

Take ADC converted value after

Use the value

Ignore the value

End of conversion

Reset the counter

and take fresh

readings

AN1711 Datasheet(PDF) 17 Page - STMicroelectronics