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ACHIEVING HIGH ACCURACY AND 13-BIT RESOLUTION WITH ST7LITE2 ADC

Figure 5 Averaging Algorithm

Table 4 is for reference only, representing the relation between the number of samples and

the accuracy. After 25 samples, it shows an LSB accuracy of 2. The number of samples to

choose depends on the application (noise level and timing) as these two are directly propor-

tional. The disadvantage of having too many samples is that it takes more time to convert the

data.

Table 4 Number of Samples vs. Accuracy

Number of Samples

Accuracy in LSB

10

4

20

3

25

2

30

2

40

2

50

2

START

Initialize ADC variables, and select analog channel,

Total = 0

Start ADC

Read the ADC output registers after End of conversion

Add read value to Total

Num. of Conv.

= N?

yes

no

Average = Total / N

Use the Result