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Chapter 2 / Robotic System Overview
DYN2009635 20 MH and RXDMP49 11.0952 MHz “AT”
Cut Quartz Crystal Oscillator
The PIC16F876 RISC microcontroller uses a 20 MHz crystal, and the
MCP2150 uses an 11 MHz crystal. While the PIC16F876 has an 8 MHz
internal oscillator, a higher clock rate is desired for the communica-
tion link, analog input turnaround, and motor control reaction time
via the digital outputs. Figure 2.9 shows the physical dimensions of
the crystals.
Figure 2.9
Physical dimensions
of the RXDMP49
and DYN2009635
crystal oscillators.
Side and bottom
views.
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