Transcript Samantha - SSI Robotics

Samantha
Samantha
• What is it?
– It is a Wi-Fi interface for the Lego Mindstorms
– It replaces the Bluetooth connection for
running matches
• It is mostly for running matches
• You theoretically can download software over this
link
Samantha
• How does it hook up to the NXT?
– The Samantha hooks up to the USB port on
the NXT – It does not use up a sensor port
– It will see the “name” of your NXT and use
that to identify your NXT to the field control
system
Samantha
• What does it mean to me for competition?
– You do not have to bring a laptop to the
competition field!
– You do not have to bring joysticks to the
competition field!
– All you have to bring is your robot (and drive
team)
– Matches will be controlled from a central
computer
Samantha
• What does it mean to me for practice?
– You will need Wi-Fi to test your robot under
actual competition conditions
– Samantha can use an existing Wi-Fi
infrastructure
• Configuration is done using the Samantha Network
Configuration program (included with FCS)
• The network information is written to a file on a
USB flash drive.
• This file is read by the Samantha to configure the
network
Samantha
• What does it mean to me for practice?
– The Samantha FCS will be available for download.
• Team Resources
• FTC Toolkit
• Field Control System Resources
– The installation package also provides utilities for
verifying the network connection
• RobotC
– Samostat
• Labview
– Samostat
– Communications_status
Samantha
• What is Samostat?
– The Samostat program is a useful Wi-Fi
status and network verification tool
– The first message you may see is Acquiring..
Samantha
• What is Samostat?
– When the Samantha module connects the
network information is displayed on the
screen
Samantha
• What does Samostat tell me?
– The first line is WiFi Stat and the software
version number (1.42 in this case)
– Next is the IP address of the module
– Following that is a series
of number indicating the
basic state of the TCP
connection
Samantha
• Networks line?
– These are the Wi-Fi networks the Samantha
has detected. There are two character
positions in front of the network names. If the
first character is an * then this is the
connected network. If the
second character is an @,
then it is an ad hoc
network, if it is blank, it is
an infrastructure network.
Samantha
• What is the Comunications Status
program?
– The Communications Status (LabView only)
program is a communications monitoring tool
– It tracks the messages being received in the
NXT mailbox and reports the status to the
NXT LCD
Samantha
– The first line provides NXT and external battery
voltage
• Msg Cnt is the number of messages received
• Msg Rate is the packet to packet time (not averaged)
• Msg Delay is the additional packet to packet time relative to
the expected 20 messages per second time slice. This is
reset to 0 every 5 seconds.
Samantha
• The Communications Status program
– This is strictly meant as a verification tool for
message traffic integrity
– The writes to the display take too long, and
the messages get read too fast to all be
visible to the user.
– The data displayed is provided as a
“reasonable” representation of the message
traffic.
Samantha
• Mounting
– Preferred is vertical with USB facing down
– Horizontal has most potential for loosened
connections, but this can be mitigated with
proper strain relief
– Use zip ties to hold cables in place
– Mount as high as possible
– Do not bury it behind a bunch of metal
Samantha
The ½” gear hub that is supplied in the TETRIX kit is the right size and
is a good choice to use as a spacer for proper strain relief with the
original Samantha. Experiment to find the best solution with the
newer modules.
Samantha
• Robot Power Management Using
Anderson Powerpole© Connectors
•
This comes from a document on the USFIRST web site Samantha resources
Samantha
• The newer Samantha units work the same as the
older units. The connectors seem to be a bit more
rugged.
• CAUTION
– If you are loading new network information (re-flashing
the unit). Do not attempt to only change the encryption
type for a network. The Samantha does not seem to
correctly update if only the encryption has changed. It is
best to rename the network to something different then
flash again to set the proper name and encryption.
Samantha
• Any Questions?