Builders guide robot pacman.pdf

is held for several clock cycles and each transition period amountsto half a clock cycle. Since both chips were set to operate with thesame clock frequency, the decoder is able to unscramble andsynchronize the data received to its own internal clock. Figure 16illustrates how the data is unscrambled at the decoder. Note thatVT (valid transmission) only goes high once two sets of wordshave been received from the encoder.Figure 16. Encoder and Decoder transmission protocol4.2.3 RF ModulesThe RF module was selected based on reliability, size, and easiness ofimplementation. RF modules made by Abacom, Melex, MingMicrosystems, Ramsey, Linx and RF solutions were researched, however,the modules produced by Linx Technologies was chosen based onprevious project success and because it required the least amount ofexternal circuitry. In addition, since our controller’s case had a sizerestraint, the Linx transmitter module was ideal due to its small packaging.See Figure 17 and Figure 18 for their schematics.13