User Manual

Software Design

ZSTAR3 Reference Design Manual, Rev. 0.1

Freescale Semiconductor 5-37

Preliminary

5.3.5.2 ZSTAR3_MODE

This command is using only with ION device mounted on Sensor Board. Command can swtich individual

digital work modes on digital sensor.Sensor board answer by ZSTAR3_DATA command.

5.3.5.3 ZSTAR3_OFF

This command request switch off sensor. Is available only on Sensor Boards without power switch.

5.3.5.4 ZSTAR3_GSEL

This command is used as a request of change actual g select of sensor to new.Sensor board answer by

ZSTAR3_DATA command.

5.3.5.5 ZSTAR3_DATARATE

This command is used as a request of change actual datarate of sensor to new.Sensor board answer by

ZSTAR3_DATA command.

5.3.5.6 ZSTAR3_FLAG

This is special additional subcommand that is used only with initial ZSTAR_BROADCAST command to

recognize a RF protocol type - Original ZSTAR RF or ZSTAR3 RF Protocol.

5.3.6 ZSTAR3 RF Protocol description

ZSTAR3 Rf portocol is based on star RF network topology. The USB Stick is a master of the network and

Sensor boards are slaves. All network runs within time based RF protocol, thus each device of the ZSTAR3

RF network has own time in each period for transmit. Receive time it’s little different, all Sensor Boards

opens receive window in some time and tries to catch synchronization/data transmition of master, but USB

Stick (master) has opened receive window all time when RF Sensor Boards transmits.

The ZSTAR3 devices runs with simple state machine:

1. Init state - Devices initialize all neccesarry hardware peripherials and software drivers. After

initialization is done, state machine jumps to Broadcast state.

2. Broadcast state: this is little bit outdated state that is keep in protocol only for compatibilities

modes of ZSTAR3 protocol with original protocol devices.

— Master (USB Stick) - the ZStar3 protocol needs only find out free channel for prepared RF

network, but because the ZStar3 demo supports original ZStar RF protocol, then this state is

important only for compatibility capatibilities of the ZSTAR3 demo.

— Slave (Sensor board) - In this state the Sensor Board is looking for the ZSTAR3

communication. Ad when it’s found the RF communication with right NetNum number and its

time position is free, jump to the Run State of RF protocol. If not jumps to the Sleep state.

3. Compatibility state with original ZSTAR: