Zitat:
Servo Position
The position (low byte/high byte) is a 16 bit number which directly sets the output pulse
width in uS. Setting the position to 1500 (1500uS or 1.5mS) will set most servo's to their
center position. The range of pulse widths that are normally supported are from 1000uS
(1mS) to 2000uS (2mS). It is usually possible to go beyond these limits though. On a Hitec
HS311 servo, we can set the position from 800 to 2200 to give a nice wide range of
movement. Take care though as its easy to make the servo run into its internal stops if
you give it pulse widths at the upper or lower extremes. The registers can also be read
back. The position will be the current position of the servo during a speed controlled
movement, so you can track its progress towards the requested position.
Das bedeutet, die Position wird in Mikrosekunden angegeben, Werte von ca. 1000 bis 2000 (je nach Servo etwas unterschiedlich). Da die SD21-Register aber nur 8Bit groß sind (0-255) werden die Werte auf zwei Register verteilt (16 Bit). Dabei unterscheidet man zwischen Low-Byte(das niederwertige Byte) und High-Byte(das hochwertige Byte). Die Position errechnet sich dann so: