Help with RoboRio Serial Ports -

[dougwilliams]

We are integrating a NAV6 IMU with the RoboRIO and had it working fine over USB (with USB/RS232 converter), and tried to go direct to the RoboRio RS232 port. We keep getting errors when running - similar to what we had with the USB port before we correctly passed the port (SerialPort::kUSB). We have swapped that out with SerialPort::kOnboard, but still have no luck. We tried swapping the TX/RX wires, but the RoboRIO choked after that, so we went back to the original which seemed more promising.

What should we see in the RoboRIO web page - we always seem to see two ports, but both are stuck at 9600. In the LIDAR thread someone mentiones something about the "main" I2C port not working, but the MXP one does, and I'm wondering if there is a setting somewhere that is steering logical ports to either the "On Board" ports vs the MXP ports.

Our code and most relevant setup file for serial comms is here:
https://github.com/team2053tigertron...r/FODRobot2015

Related side question 1: Where is the latest "official" downloadable source for the WPILib? I see a few repositories, but nothing I can discern as latest/official, etc. (So I can browse the functions and make sure we are using them right).

Related side question 2: Are there any links to Beta teams who used C++, and posted their code somewhere? I have only found one or two, but none that used the serial port...

[slibert]

Originally Posted by dougwilliams

We are integrating a NAV6 IMU with the RoboRIO and had it working fine over USB (with USB/RS232 converter), and tried to go direct to the RoboRio RS232 port. We keep getting errors when running - similar to what we had with the USB port before we correctly passed the port (SerialPort::kUSB). We have swapped that out with SerialPort::kOnboard, but still have no luck. We tried swapping the TX/RX wires, but the RoboRIO choked after that, so we went back to the original which seemed more promising.

What should we see in the RoboRIO web page - we always seem to see two ports, but both are stuck at 9600. In the LIDAR thread someone mentiones something about the "main" I2C port not working, but the MXP one does, and I'm wondering if there is a setting somewhere that is steering logical ports to either the "On Board" ports vs the MXP ports.

Our code and most relevant setup file for serial comms is here:
https://github.com/team2053tigertron...r/FODRobot2015

Related side question 1: Where is the latest "official" downloadable source for the WPILib? I see a few repositories, but nothing I can discern as latest/official, etc. (So I can browse the functions and make sure we are using them right).

Related side question 2: Are there any links to Beta teams who used C++, and posted their code somewhere? I have only found one or two, but none that used the serial port...

One thing to check is that the Roborio "console out" functionality needs to be disabled to use the Roborio RS-232 port.

Others have successfully integrated the nav6 with Roborio via the RS-232 port, though I don't know about doing so in c++.

[dougwilliams]

Originally Posted by slibert

One thing to check is that the Roborio "console out" functionality needs to be disabled to use the Roborio RS-232 port.

Interesting ... where is console output setting?

[Mark McLeod]

In the roboRIo WebDash.

RoboRIO Webdashboard

[Joe Ross]

Originally Posted by Mark McLeod

In the roboRIo WebDash.

And on the imaging tool. Note that if you ever have to reimage the roboRIO, the imaging tool will automatically turn the console out back on.

[razorgator]

We are also trying to get the Nav6 to run on the RoboRio using C++. We originally tried going from Nav6 to a USB input on the RoboRio (changing the initialization of the serial port to kUSB). We didn't have any luck with that approach. However, perhaps that was to be expected. I see that there is a note on the Kauai Labs website that suggests using a USB-serial cable with FTDI or Prolific chipsets. The cable we used did not have either of those.

We have moved to trying to communicate with the Nav6 via the RS-232 port onboard the RoboRio. Until this evening, we were getting messages while our code was running on the RoboRio suggesting that there was an issue with our use of SerialPort.h. While we did change the initialization parameter to kOnboard, we had not disabled the console out. When we disabled that, the messages went away. However, we are still unable to receive information from the Nav6. For testing purposes, we are just calling the GetYaw function and attempting to display it on the SmartDashboard. At the moment, no value is displayed.

Thanks for everyone's input this far. Any other suggestions are welcome!

[slibert]

Originally Posted by razorgator

We are also trying to get the Nav6 to run on the RoboRio using C++. We originally tried going from Nav6 to a USB input on the RoboRio (changing the initialization of the serial port to kUSB). We didn't have any luck with that approach. However, perhaps that was to be expected. I see that there is a note on the Kauai Labs website that suggests using a USB-serial cable with FTDI or Prolific chipsets. The cable we used did not have either of those.

We have moved to trying to communicate with the Nav6 via the RS-232 port onboard the RoboRio. Until this evening, we were getting messages while our code was running on the RoboRio suggesting that there was an issue with our use of SerialPort.h. While we did change the initialization parameter to kOnboard, we had not disabled the console out. When we disabled that, the messages went away. However, we are still unable to receive information from the Nav6. For testing purposes, we are just calling the GetYaw function and attempting to display it on the SmartDashboard. At the moment, no value is displayed.

Thanks for everyone's input this far. Any other suggestions are welcome!

The Trendnet TU-S9 USB serial adapter works on the roborio, that's the easiest integration method from a wiring perspective. There are some additional troubleshooting tips on the nav6 wiki. This has been tested with C++.

For RS-232, check your wiring. TX on the nav6 side connects to RX on the roborio side, and vice versa. And you have to connect GND on the nav6 to GND on the roborio's RS-232 connector.

To be sure the nav6 is sending data, look at the green TX led on the nav6 circuit board.

[razorgator]

Thank you for the direction.

The green TX led is lit. We will double check the RS-232 wiring this evening.

[jreneew2]

On the same team as dougwilliams here - We got the serial port working. All we had to do was switch the pinouts and uncheck console output in the roboRIO webdashboard. Now it works!

Thanks for the help!

- Drew

[slibert]

Originally Posted by jreneew2

On the same team as dougwilliams here - We got the serial port working. All we had to do was switch the pinouts and uncheck console output in the roboRIO webdashboard. Now it works!

Thanks for the help!

- Drew

You're very welcome, Drew. We've updated the nav6 troubleshooting page to capture the issue you encountered. Good luck in this year's competition!