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-   -   Incorrect voltage readout on Driver Station (http://www.chiefdelphi.com/forums/showthread.php?t=91024)

Kevin Wang 05-02-2011 15:55

Incorrect voltage readout on Driver Station
 
Whenever we are connected to the robot, the driver station always reports a voltage of 17.68 volts. This issue has been observed on multiple laptops. Has anyone else observed this issue?

kinganu123 05-02-2011 16:34

Re: Incorrect voltage readout on Driver Station
 
Just thought I'd add to the problem:
We always get somewhere between .05-.07 volts
This happened like 3 or 4 days after the switch to SmartDashboard

Joe Ross 09-02-2011 10:44

Re: Incorrect voltage readout on Driver Station
 
Quote:

Originally Posted by Kevin Wang (Post 1016300)
Whenever we are connected to the robot, the driver station always reports a voltage of 17.68 volts. This issue has been observed on multiple laptops. Has anyone else observed this issue?

What programming language are you using?

Quote:

Originally Posted by kinganu123 (Post 1016320)
Just thought I'd add to the problem:
We always get somewhere between .05-.07 volts
This happened like 3 or 4 days after the switch to SmartDashboard

Is the battery monitoring jumper installed on the analog breakout?

Alan Anderson 09-02-2011 11:48

Re: Incorrect voltage readout on Driver Station
 
The NI 9201 analog input module is only supposed to be capable of reading a maximum of ten volts. The Analog Breakout has a 680ohm/1k voltage divider in the circuit to reduce the battery voltage to something within range. The calculation of the number to display compensates for this. If somehow you're getting full battery voltage on the NI 9201 input, and if it is somehow returning that value (which is greater than it is specified to handle), you'd see about 17.68 volts on the display. An open circuit in the 1k resistor path would do it.

Your team probably has a spare Analog Breakout (one came in the kit this year and last year, and there were two with the first year's cRIO). Try swapping out the one you're using now and see if the voltage display becomes correct.

LV1601 09-02-2011 13:03

Re: Incorrect voltage readout on Driver Station
 
This happened to us before just try to install the jumper again if it not perfect then it might read wrong.

kinganu123 09-02-2011 22:06

Re: Incorrect voltage readout on Driver Station
 
No idea what the heck happened, but our bot hit a locker (don't worry the bumpers were on) and it started magically working
I guess the impact somehow fixed the wiring

cilginbilgin 20-02-2011 08:49

Re: Incorrect voltage readout on Driver Station
 
Another thing to add that issue our driver station always reads 0 voltages whenever we are connected to robot.

Does someone know how to fix this problem?

Vikesrock 20-02-2011 09:11

Re: Incorrect voltage readout on Driver Station
 
Quote:

Originally Posted by cilginbilgin (Post 1027330)
Another thing to add that issue our driver station always reads 0 voltages whenever we are connected to robot.

Does someone know how to fix this problem?

Common causes of this are not installing the jumper on the Analog Breakout and not powering the Analog Breakout board.

The jumper should be installed on the outside two pins of the 3 pin header.

The Analog Breakout requires 12V power from the Power Distribution board in order to run.

The Analog Breakout Datasheet provides more detail if you need it:
http://www.usfirst.org/uploadedFiles...out%281%29.pdf

wireties 21-02-2011 14:01

Re: Incorrect voltage readout on Driver Station
 
Ours is reading zero also. I have swapped analog modules and breakouts and the jumper is in the correct position. We are playing with custom dashboard code at the moment and getting message errors. Could that be messing it up?

TIA

Alan Anderson 21-02-2011 14:32

Re: Incorrect voltage readout on Driver Station
 
Quote:

Originally Posted by cilginbilgin (Post 1027330)
...our driver station always reads 0 voltages...

Quote:

Originally Posted by wireties (Post 1028408)
Ours is reading zero also.

It would greatly help us help you if you could take a clear photo of your analog breakout while the problem is occurring and post it here, showing the jumper and the wiring connected to it.

wireties 21-02-2011 15:57

Re: Incorrect voltage readout on Driver Station
 
photo attached - sure looks correct

Alan Anderson 21-02-2011 16:11

Re: Incorrect voltage readout on Driver Station
 
Quote:

Originally Posted by wireties (Post 1028481)
photo attached - sure looks correct

It looks okay...except for the lack of any indication that there is actually power applied. There's a green LED that ought to be lit. What voltage do you see using a meter on the white Wago connector?

wireties 21-02-2011 16:20

Re: Incorrect voltage readout on Driver Station
 
Quote:

Originally Posted by Alan Anderson (Post 1028495)
It looks okay...except for the lack of any indication that there is actually power applied. There's a green LED that ought to be lit. What voltage do you see using a meter on the white Wago connector?

Sorry - the power was not on - the green LED is on when power is applied - we see 12.07V on the wago connector. It must have something to do with the dashboard packet format not matching (because we are customizing it).

TIA

Greg McKaskle 21-02-2011 17:45

Re: Incorrect voltage readout on Driver Station
 
Customizing a dashboard will not break the robot battery voltage communications. They are very independent.

Greg McKaskle

Alan Anderson 21-02-2011 23:21

Re: Incorrect voltage readout on Driver Station
 
The problem became obvious once I realized what to look for.

Keith, your NI 9201 module is in Slot 8 of the cRIO chassis. It needs to be in Slot 1, at the end nearest the Ethernet ports and power connector.


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