Arduino code techniques: Unterschied zwischen den Versionen
Aus www.wiki.ardumower.de
(→Mean filter) |
(→Mean filter) |
||
Zeile 2: | Zeile 2: | ||
=Mean filter= | =Mean filter= | ||
− | Problem: you have multiple ADC measurements (battery, ultrasonic etc.) that can contain outliers. What value is the 'most seen value'? | + | *Problem: you have multiple ADC measurements (battery, ultrasonic etc.) that can contain outliers. What value is the 'most seen value'? |
− | Solution: This code will sort and choose the center value. | + | *Solution: This code will sort and choose the center value. |
− | Example: | + | *Example: |
− | Measurements: 32,7,7,1,6,8,7,9,23,7,8,9,7 | + | *Measurements: 32,7,7,1,6,8,7,9,23,7,8,9,7 |
− | Sorted: 1,6,7,7,7,7,7,8,8,9,9,23,32 | + | *Sorted: 1,6,7,7,7,7,7,8,8,9,9,23,32 |
− | Returned: 7 (center value) | + | *Returned: 7 (center value) |
unsigned int ADCmedian(int pin, int count) { | unsigned int ADCmedian(int pin, int count) { |
Version vom 11. September 2014, 15:51 Uhr
This page shows common code techniques that can be useful on the Arduino.
Mean filter
- Problem: you have multiple ADC measurements (battery, ultrasonic etc.) that can contain outliers. What value is the 'most seen value'?
- Solution: This code will sort and choose the center value.
- Example:
- Measurements: 32,7,7,1,6,8,7,9,23,7,8,9,7
- Sorted: 1,6,7,7,7,7,7,8,8,9,9,23,32
- Returned: 7 (center value)
unsigned int ADCmedian(int pin, int count) { int values[count], last; uint8_t j, i = 0; values[0] = 0; while (i < count) { last = analogRead(pin); if (i > 0) { for (j = i; j > 0 && values[j - 1] < last; j--) // Insertion sort loop. values[j] = values[j - 1]; // Shift ping array to correct position for sort insertion. } else j = 0; // First ping is starting point for sort. values[j] = last; // Add last ping to array in sorted position. i++; // Move to next ping. if (i < count) delay(1); } return (values[count/2]); // Return the median. }