User Manual

Software Design

ZSTAR3 Reference Design Manual, Rev. 0.1

Freescale Semiconductor 5-39

Preliminary

for all 16 devices elapses. When the master catches any message from slaves, process it and immediatly

open new receive window, if the last message wasn’t from 16th Slave device..

Figure 5-3. ZSTAR3 RF protocol period

5.4 ZSTAR3 USB protocol - Extended STAR protocol

The ZSTAR3 demo uses a subset of the original ZSTAR demo protocol commands.The Original ZSTAR

is build on STAR demo protocol. This way, most of the software originally developed for the

RD3152MMA7260Q (ZSTAR) and RD3112MMA7260Q (STAR) is also usable with the ZSTAR3.

The STAR demo communicates over the RS232 serial line with a simple text-based protocol. The same

protocol is used in ZSTAR/ZSTAR3 for communication between the USB stick and a PC (over a virtual

serial port). The PC application sees the same interface (serial port) and the same protocol as if a STAR

demo was connected.

Because the ZSTAR3 can serve up to 16 connected sensor boards, all commands that works direct with

sensor boards are communicated with one selected board by ‘N’ command from 5.4.3, “Subset of new

added ZSTAR3 protocol commands.

5.4.1 Subset of original STAR protocol commands

The ZSTAR3 software contains all unchanged original STAR commands. Some commands can send

extended information in ZSTAR3 mode - ZSTAR3 USB protocol extend some Original commands when

PC send any command from new subset of command table. These extended information return to PC

information of result individual commands.

Slave 0

MCU

Master

MCU

SMAC Interupts

Slave 1

MCU

Slave 8

MCU

ZStar3 RF protocol typical period