Transcript Troubleshooting

VEX Troubleshooting
J.M. Gabrielse
The Troubleshooting Process
Describe the problem:
– What did you expect the robot to do?
– What is the robot doing differently?
J.M. Gabrielse
Potential Problem Areas
• Power (Joystick & Robot Batteries)
• Communication (VEXnet Connections)
• Robot (Software/Hardware)
J.M. Gabrielse
Check the Lights
(on the robot & the joystick)
(only works on the joystick
when linked)
(no backup battery is only
indicated if the competition
cable is connected)
(red)
Main Battery = Dead (<5.5v) or CORTEX Off
(yellow)
Main Battery = Low (<6.5v)
(green)
Main Battery = Good
Solid
All Good: Both Joysticks connected
Solid + 1 Blink
All Good: Tx1 Joystick connected
Fast (red) [3]
Fault: Low Backup Battery (0v-8v)
Blip (yellow)
Startup - looking for USB device
Fast (yellow)
Linking - Searching for VEXnet mate
Fast (green)
Linked
Slow (yellow)
Linked - Data quality reduced
Solid (green)
Tethered
Slow (red)
Fault: Lost Link - Searching for VEXnet mate
Off
No Competition connection
Solid (green)
Driver
Fast (green)
Autonomous
Fast (yellow)
Disabled
J.M. Gabrielse
Power Checklist
 Check the joystick light
 Check the robot light
J.M. Gabrielse
Check the Joystick Light
Symptom: the joystick light is red
Solution: put fresh AA batteries in the joystick
J.M. Gabrielse
(red)
Main Battery = Dead (<5.5v) or CORTEX Off
(yellow)
Main Battery = Low (<6.5v)
(green)
Main Battery = Good
Solid
All Good: Both Joysticks connected
Solid + 1 Blink
All Good: Tx1 Joystick connected
Fast (red) [3]
Fault: Low Backup Battery (0v-8v)
Check
the Robot
Light
Symptom: the robot light is red (solid or slow blink)
Solution: put a fresh main battery on the robot
Symptom: the robot light is red (fast blink)
Solution: change the backup battery J.M. Gabrielse
Connections
Blip (yellow)
Startup - looking for USB device
Fast (yellow)
Linking - Searching for VEXnet mate
Fast (green)
Linked
Slow (yellow)
Linked - Data quality reduced
Solid (green)
Tethered
Slow (red)
Fault: Lost Link - Searching for VEXnet mate
Symptom: the VEXnet light stays
red
Test: Connect with the USB A-A
cable
Solutions: Try other VEXnet
J.M. Gabrielse
Hardware & Software
 Check the wiring.
 Use the online window to determine if you
have a hardware or a software problem.
J.M. Gabrielse
Check the Wiring
Open the Project menu → Select the Controller Configuration
 Are the wires plugged in the correct ports?
J.M. Gabrielse
Use the USB A-A cable to connect your robot to the computer.
Open the Tools menu → Select the On-Line Window → Click the Enable button
Test
Hardware
with Online
Control
If motors or
servos don’t work
properly it’s a
hardware problem
else it’s software.
J. M. Gabrielse
Drag the
sliders to
adjust motor
speeds and
servo
positions.
J.M. Gabrielse
Hardware Checklist





lights
wiring
axles
screws
motors
If you can figure out the
problem, you can fix it.
J.M. Gabrielse
Check Axles
Is a motor turning, but the axle isn’t?
Push the axle all the way in.
Replace clutches (if in use) if the axle still won’t
turn.
J.M. Gabrielse
Tighten Loose Screws
Loose screws can cause friction (rubbing).
This can make the robot drive funny.
If they aren’t causing a problem now, they
will later.
J.M. Gabrielse
Motors & Servos Look Similar
(Check to make sure they aren’t switched)
Servos won’t go all the way around. Motors will.
They are labeled on the back.
J.M. Gabrielse
Check Motor Temperature
(Are they warm/hot to the touch)
Solutions:
• Add power by adding motors to help
the overheating motors.
• Reduce power consumption by
making the robot lighter, balancing
loads (use counterweights or rubber
bands), or avoiding stalls while
driving (don’t get into pushing
matches).
The new two-wire motors have thermal breakers so they shut down when
overheated. They don’t burn up, they just stop working for a little while.
J.M. Gabrielse
Software Checklist
 check
lights
 check
wiring
 reload
firmware
 default
program
 your
program
If you can figure out the
problem, you can fix it.
J.M. Gabrielse
Check Game Light
Off
No Competition connection
Solid (green)
Driver
Fast (green)
Autonomous
Fast (yellow)
Disabled
J.M. Gabrielse
Reload Firmware
Unplug the VEXnet key from the
robot or joystick.
Use the USB-A to USB-A cable
to connect directly to the
computer.
Open the IFI VEXnet Firmware
Upgrade utility, located in the
easyC v4 for Cortex folder of
the Start menu.
Click SEARCH
If that doesn’t work click
BootLoad and then try again.
Click DOWNLOAD.
Repeat for both the robot and
the joystick.
J.M. Gabrielse
Reload the Program
After reloading the
firmware the
program needs to
be reloaded.
J.M. Gabrielse
Test Software with the Default
Code
• If the default code works fine then the problem is
your program.
• Check for endless loops.
– If you have an endless loop in your autonomous
function, you will never get to operator control.
• Check to make sure you set everything the way
you set it up in the controller configuration.
J.M. Gabrielse
Resources
•
•
•
•
Cortex Joystick LED Codes
(http://content.vexrobotics.com/docs/Cortex_Joystick_LED_Codes_052010.p
df)
VEXnet Troubleshooting Tips
(http://www.vexforum.com/wiki/index.php/VEXnet_Joystick#Troubleshooting)
Vex Inventor’s Guide: ?·? - ?·?
Vex Forum (http://www.vexforum.com):
– search previous posts, someone else might have already
– post your own question if someone hasn’t already asked it
J.M. Gabrielse
Notes:
I figured out a way to rescue a Cortex controller that wouldn't connect to the firmware upgrade utility (it still doesn't work on my Windows 7
laptop). I've only done three so far, and I had to try some of the steps multiple times. However, this is what I think is going on.
The problem:
"USB Device Not Recognized" message from the computer, all red lights and then none on the Cortex
The solution:
Use the battery to power on the Cortex while holding in the config button. Then leave it on and then connect the USB A-A cable to the
computer.
If I tried to do the config button trick with power from the USB cable, but the device wasn't in the right state when I connected it, so the computer
couldn't recognize it.
Notes:
I also had a hard time downloading code onto the rescued Cortex controllers. It took several attempts before I was able to successfully load the
code. I certainly don't trust these controllers anymore.
Suggestions:
Please continue to test your firmware upgrade utility with Windows 7. It worked a couple times on my Windows 7 (Home Premium x64)
laptop and then stopped. I suspect USB driver issues. However, EasyC works fine.
Also, I found that many teachers were confused by the firmware upgrade utility: After pressing "Search" and they received a message telling
them to press "Download" but it was grayed out. Instead they had to first press "Bootload" and then press "Download".
Also, it would be nice if the firmware upgrade didn't say to contact Vex when the access ID number is lost. A message suggesting that pairing
the cortex and the joystick would be more helpful. If you really want to be contacted, put the phone number in the message.
Another weird issue that I discovered is that sometimes you can't pair the joystick and cortex until some code is loaded (not always, just
sometimes). I don't know why.
J.M. Gabrielse