Driver Station User Messages Not Updating

Technical C/C++
1

Hello, we are currently working on vision tracking for our robot using Wind River C++. We were attempting to use messages as debugs and realized that we are not receiving updates in the ‘User Messages’ section of the Driver Station.

This is the code being used to send and update messages to the Driver Station:


dsLCD->Printf(DriverStationLCD::kUser_Line1, 1,"Message
");
dsLCD->UpdateLCD();

The user message will sometimes print once when the code is first deployed, but will not continue to update after that. We have tried running this command at various points throughout the program without success.

Any ideas???

2

I’m not sure if this fixes your problem, but we’ve been printing data to the driver station like this:


//initialize		
DriverStationLCD *dsLCD = DriverStationLCD::GetInstance();


dsLCD->Printf(DriverStationLCD::kUser_Line1, 1, "Here is some text");
dsLCD->UpdateLCD();
Wait(0.1);

or like this:


dsLCD->PrintfLine(DriverStationLCD::kUser_Line1, "Here is some more text");
dsLCD->UpdateLCD();
Wait(0.1);

Because you defined the line to print on (the number after kUser_Line1, x), you don’t need the /n to go to the next line (I think). This may need confirmation. Good luck :smiley:

3

I haven’t used the LCD yet, but it works by sending a big block of text that sets every character on the display. You don’t want to include newlines (even if the LCD hardware handles them, it would mess up the position of the other text being displayed).

Your code will write “Message” on line 1 starting at column 1. If you run it again it will do the same thing. Maybe try something like this to see if it’s updating:


dsLCD->Printf(DriverStationLCD::kUser_Line1, 1, "Time %8.3f", Timer::GetPPCTimestamp());
dsLCD->UpdateLCD();
4

Thanks, we were able to debug the code with that :slight_smile:

5