ANNOUNCING: navX MXP Robotics Navigation Sensor

[slibert]

Originally Posted by taichichuan

If you need someone to help test the updates with the 2016 Beta libraries, we'd be happy to help.

Mike A.
FRC #116

Hi Mike,

Beta versions of the navX-MXP C++/Java Libraries which are compatible the 2016 Beta WPI Libraries (C++/Java) are now available for testing. Anyone interested can PM me for details on getting a copy of the beta libraries.

The functional changes are:

- C++/Java: navX-MXP Libraries compiled w/latest 2016 WPI FRC beta libraries.
- C++/Java: I2C transfer sizes, previously limited to 7 bytes/transfer in the WPI Library, have been increased. The navX-MXP libraries now transfer all I2C data in a single bus read transaction, increasing performance.

Not yet changed:

- Java: to link w/the navX-MXP Java library, the WPI Library's build.properties file must be edited, as described in these directions. This additional step will be removed before the final release of the navX-MXP C++/Java Libraries for 2016.

[Jonathan L.]

Originally Posted by taichichuan

Unfortunately, the examples fail to build in the 2016 control system betas. The compiler complains about:

"invalid new expression of abstract class type 'AHRS'" and dies a horrible death.

Just to make things clear: Is this just a problem with C++/Java? Is the 2016 beta navX LabVIEW code working? If not will it be updated by kickoff? Thank you!

[slibert]

Originally Posted by Jonathan L.

Just to make things clear: Is this just a problem with C++/Java? Is the 2016 beta navX LabVIEW code working? If not will it be updated by kickoff? Thank you!

Yes, the previously reported compile problem when used with the 2016 FRC beta was limited to C++ and Java, and a fix for that issue is now in beta.

LabView is good to go. James Parks, the creator of the new V2 LabView NavX-MXP Library (http://www.chiefdelphi.com/forums/sh...highlight=NavX) has successfully tested the LabView library against the 2016 Beta, and indicates it works fine with the SPI, I2C and TTL UART interfaces.

The only further work remaining is to deal with an issue found when testing the USB interface against the FRC 2016 beta image/library.

So give it a go and let us know how it goes. The SPI interface is highly recommended.

[Jonathan L.]

My team is not a beta testing team, so I can't test it until build season. Anyway, we got the navX working with the 2015 FRC LabVIEW software recently. Looking forward to using it next year!

[slibert]

The navX-MXP Java and C++ Libraries have been updated to work w/the new 2016 WPI Libraries. And the Zebracorns have released an updated LabView library for 2016. The latest build of all these libraries is available now.

In addition, Team Shockwave has created a C# RoboRIO Library that also features a navX-MXP Library.

And there are more examples than ever both in the examples provided with the C++, Java and LabVIEW Libraries, as well as in the recent team code releases, including those of team 2465 (Kauaibots).

And we've heard wind of a Python RoboRIO Library being developed as well - we'll let you know when more details are available on that.

KauaiLabs wishes everyone an incredible 2016 build season!

[topgun]

Where is the CAD file for the MXP located? I downloaded the zip file, checked Git, but I still don't see the actual CAD file for the board itself. I am looking for the SolidWorks CAD file.

Thank you.

[Jonathan L.]

Originally Posted by topgun

Where is the CAD file for the MXP located? I downloaded the zip file, checked Git, but I still don't see the actual CAD file for the board itself. I am looking for the SolidWorks CAD file.

Thank you.

Get the download from this page http://www.pdocs.kauailabs.com/navx-mxp/software/

The CAD files are in the zip file; no need to install everything. I don't see a Solidworks model there, but there are several SketchUp files and an STL file.

[schleprock]

Originally Posted by slibert

The only further work remaining is to deal with an issue found when testing the USB interface against the FRC 2016 beta image/library.

we just received a couple of the navx's and we want to use the USB port as our roborio is mounted on the side of the robot in a verticle position. i tried the DataMonitor example and i can see everything when we plug the navx into the mxp port. but i see nothing when we connect it via USB. i changed Port parameter to the AHRS constructor to SerialPort.Port.kUSB but no output to the smartdashboard. it doesn't throw an exception, so the AHRS class instance is getting constructed. there's just doesn't seem to be any communication. is the issue you refer to? and is it going to be fixed anytime soon?

thanks

[schleprock]

Originally Posted by slibert

You will need to connect a total of 4 wires between two sets of connectors which are shown in the navX MXP RoboRio installation photo. The RoboRio SPI connector is at the top left of the photo. The navX MXP SPI connector is the middle row of 6 pins, just above the white arrowhead indicating the Y (Roll) axis.

First, carefully connect the following pins between the RoboRio SPI Connector and the navX MXP SPI Connector:

RoboRio <--->  navX MXP

CS0     <--->  CS
MISO    <--->  MOSI  [Note that the pin names are different on each side]
MOSI    <--->  MISO  [Note that the pin names are different on each side]
SCLK    <--->  SCLK

(Note: Don't connect the RoboRio SPI Connector's CS1, CS2, CS3, GND, 3.3V and 5.V pins)

Look closely at the silkscreen on the navX MXP, and you'll see the pin names labelled directly underneath each of the SPI pins.

we tried to communicate to the navx via usb but had no success, so i'm looking to connect via SPI. i understand the pinouts you have here, but what about PWR and GND? should i just use the USB as power and communicate via SPI? or should i connect the PWR (which one, 3.3 or 5V) and GND on the SPI breakout port?

[slibert]

Originally Posted by schleprock

we tried to communicate to the navx via usb but had no success, so i'm looking to connect via SPI. i understand the pinouts you have here, but what about PWR and GND? should i just use the USB as power and communicate via SPI? or should i connect the PWR (which one, 3.3 or 5V) and GND on the SPI breakout port?

Yes, USB is not working (used to work w/2015 RoboRIO firmware, but no longer works w/2016 RoboRIO firmware).

SPI is the recommended interface. The recommendation is to connect both USB power and the 5V/GND power from the SPI. The navX-MXP will automatically switch between the power supplies as needed. If the 5V power from the SPI connector goes away (this can happen in a RoboRIO stage 2 brownout), the power from the USB connector (which is a valid 5V even in a stage 2 brownout) will be used automatically.

You may need to shield the SPI connecting cable, since the clockrate of this interface by default is 2Mhz. And a long cable may cause problems, too. You do have the option of decreasing the SPI clockrate, which may help if there is signal degradation on the SPI interface.

[schleprock]

Originally Posted by slibert

Yes, USB is not working (used to work w/2015 RoboRIO firmware, but no longer works w/2016 RoboRIO firmware).

SPI is the recommended interface. The recommendation is to connect both USB power and the 5V/GND power from the SPI. The navX-MXP will automatically switch between the power supplies as needed. If the 5V power from the SPI connector goes away (this can happen in a RoboRIO stage 2 brownout), the power from the USB connector (which is a valid 5V even in a stage 2 brownout) will be used automatically.

You may need to shield the SPI connecting cable, since the clockrate of this interface by default is 2Mhz. And a long cable may cause problems, too. You do have the option of decreasing the SPI clockrate, which may help if there is signal degradation on the SPI interface.

thanks for the quick reply. as far as the USB cable, do we need to alter the USB cable to only provide PWR/GND and not data, or can we just use a regular USB cable.
just to make sure, we connect the 5V to the breakout SPI port PWR pin on the navx board, correct? there was no indication of 5V or 3.3V on the PWR pin.

[schleprock]

Originally Posted by schleprock

thanks for the quick reply. as far as the USB cable, do we need to alter the USB cable to only provide PWR/GND and not data, or can we just use a regular USB cable.
just to make sure, we connect the 5V to the breakout SPI port PWR pin on the navx board, correct? there was no indication of 5V or 3.3V on the PWR pin.

one more question, when i instantiate the AHRS class which enumerated type do i pass in?
SPI.Port.kMXP
this seems to imply using the SPI connections on the mxp connection. i'm going to use the breakout SPI connection. is there another enumerated type to use?

thanks...

[Joe Ross]

Originally Posted by schleprock

one more question, when i instantiate the AHRS class which enumerated type do i pass in?
SPI.Port.kMXP
this seems to imply using the SPI connections on the mxp connection. i'm going to use the breakout SPI connection. is there another enumerated type to use?

I'm not sure what you mean by the breakout SPI connection. Onboard the RoboRIO, there are 4 SPI CS, and one on the MXP. You need to specify which one you are using. See http://first.wpi.edu/FRC/roborio/rel.../SPI.Port.html

[schleprock]

Originally Posted by Joe Ross

I'm not sure what you mean by the breakout SPI connection. Onboard the RoboRIO, there are 4 SPI CS, and one on the MXP. You need to specify which one you are using. See http://first.wpi.edu/FRC/roborio/rel.../SPI.Port.html

ok, if i hook it up to CS0 on the roborio, then i assume i need to use: kOnboardCS0

ie: SPI.Port.kOnboardCS0

not sure how to specify ports on the roborio. when most people talk about the various ports, they seem to mean those available through the mxp port. if they're talking about using a port that is detached from the mxp, but available on the mxp, i've seen brokenout used... so how do you specify the SPI port connections that are separate from the mxp port?

thanks

[slibert]

Originally Posted by schleprock

thanks for the quick reply. as far as the USB cable, do we need to alter the USB cable to only provide PWR/GND and not data, or can we just use a regular USB cable.
just to make sure, we connect the 5V to the breakout SPI port PWR pin on the navx board, correct? there was no indication of 5V or 3.3V on the PWR pin.

You can just use a regular USB cable.