SPI in WPILib

jrothr...@hdsd.org

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Jun 30, 2020, 11:46:08 PM6/30/20

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I have finally finished my schoolwork and have begun to play around with the VMX-Pi a bit. I do not know if I mentioned this (and if so, sorry), but the updates are working for I2c. I have the color sensor and a Pixy2 working through I2c. I am using the Pseudo Resonance library for the Pixy2 and though it is working for the most part, moving the servos for the attached base lock up the pixy. I am wondering if the issue could be that I2C does not have the bandwidth for setting the servos.

I am using the MXP port (by selecting option 4 in the init method). I also tried changing the clock rate. It did not help either.

Pseudo Resonance says they recommend using SPI instead. When trying to get that to work, I get the following errors...

VMX HAL: SIGTERM signal received.
VMX HAL: closing pigpio library to release VMX resources.
At VMXPi::Terminate
VMX HAL: pigpio library closed and VMX resources released.
Robots should not quit, but yours did!
Warning at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:291): Robots should not quit, but yours did!
Unexpected return from startCompetition() method.
Error at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:297): Unexpected return from startCompetition() method.
Error! Inactive Notifier discovered during HAL_WaitForNotifierAlarm.Thu Jun 25 11:18:06 2020 - WARN : Error clearing CAN HW RX Buffer 0 Filter 0.
(VMXCAN.cpp [922])
Thu Jun 25 11:18:06 2020 - WARN : Error clearing CAN HW Mask for RX Buffer 0.
(VMXCAN.cpp [937])
*******VMX HAL SPIClient Performance*******

- Writes:
Total #: 27
Avg Us: 151
Min Us: 63
Max Us: 283
# long: 0
# lng2: 0
# lng3: 0
MinWait: 25
MaxWait: 73

Write CRC Errors: 0
Write Retries: 0
Write Failures: 0

- Reads:
Total #: 226760
Avg Us: 199
Min Us: 51
Max Us: 303
# long: 1
# lng2: 0
# lng3: 0
MinWait: 12
MaxWait: 24

Read CRC Errors: 0
Read Retries: 0
Read Failures: 0
*******************************************
2020-06-25 11:18:06 spiClose: pigpio uninitialised, call gpioInitialise()
VMX HAL: Error closing SPI AUX Channel 2.
Entering VMX HAL Internal Kill Handler.
Entering VMX HAL Internal Kill Handler.
MAU HAL: Error expiring IO Watchdog.

I did not post as a bug as I am wondering if I am doing something wrong. Does anyone have any idea what that could be?

I am using the following tutorial.

https://github.com/PseudoResonance/Pixy2JavaAPI/wiki/Using-the-API

This hardware is amazing. Thank you.

~Jacob

Scott Libert

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Jul 1, 2020, 6:47:13 PM7/1/20

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Hi Jacob,

1) Regarding I2C, if you want to run the I2C bus at a higher rate (400Kbps) rather than run at the default 100Kbps, please follow these instructions:

By default, the Raspberry Pi I2C bus speed is 100Khz (“Standard Mode”). To change the bus speed to 400Khz (Fast Mode) follow these I2C bus speed configuration instructions. Note that the I2C-capable device to which VMX-pi is connected may only communicate at a lower speed than 400Khz; consult the external device technical documentation for further details.

2) Unfortunately, there aren't any clues in the logs you attached to your message regarding troubles accessing SPI. Can you please send or attach a copy of your code and we can review that and perhaps try to reproduce it on our side?

- scott

jrothr...@hdsd.org

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Jul 1, 2020, 10:29:27 PM7/1/20

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Scott,

Thank you. That is helpful info about the I2C speed. I will look into it and report back. If that works, I am not sure our team needs SPI. It is also possible that the servos

As for the SPI, I have not uploaded our code to git but will post it below. Is there a test you know of that I could do to easily ensure I have SPI set up and working?

Here is our code...

Robot.java

/*----------------------------------------------------------------------------*

/

*/

/* Open Source Software - may be modified and shared by FRC teams. The code

*/

/* must be accompanied by the FIRST BSD license file in the root directory of

*/

/* the project.

*/

/*----------------------------------------------------------------------------*/

package frc.robot;

import java.util.ArrayList;

import edu.wpi.first.wpilibj.TimedRobot;

import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;

import io.github.pseudoresonance.pixy2api.*;

import io.github.pseudoresonance.pixy2api.Pixy2CCC.Block;

import io.github.pseudoresonance.pixy2api.links.SPILink;

/**

* PIXY SPI EXAMPLE

* A few notes

* 1.) Two things need to be added to the build.gradle file. See the attached

tutorial document

* 2.) This code is for using Chip Select 0 (CS0) and the onboard SPI Port

* 3.) If you are using SPI mode, go into PixyMon and set the control mode to

SPI

*/

public class Robot extends TimedRobot {

/**

* This function is run when the robot is first started up and should be used

* for any initialization code.

*/

private Pixy2 pixycam;

boolean isCamera = false ;

//private SPILink spi;

int state=- 1 ;

@Override

public void robotInit () {

pixycam = Pixy2.createInstance(new SPILink()); // Creates a new Pixy2 camera using SPILink

}

@Override

public void teleopPeriodic () {

if (!isCamera)

state = pixycam.init(4); // if no camera present, try to initialize

isCamera = state>= 0 ;

pixycam.setLamp((byte) 1, (byte) 1);

SmartDashboard.putBoolean( "Camera" , isCamera); //publish if we are connected

pixycam.getCCC().getBlocks( false , 255 , 255 ); //run getBlocks with arguments to have the camera

SmartDashboard.putNumber( "Stuff" , pixycam.getCCC().getBlocks() );

//acquire target data

ArrayList<Block> blocks = pixycam.getCCC().getBlockCache(); //assign the data to an ArrayList for convinience

if (blocks.size() > 0 )

{

double xcoord = blocks.get( 0 ).getX(); // x position of the largest target

double ycoord = blocks.get( 0 ).getY(); // y position of the largest target

String data = blocks.get( 0 ).toString(); // string containing target info

SmartDashboard.putBoolean( "present" , true ); // show there is a target present

SmartDashboard.putNumber( "Xccord" ,xcoord);

SmartDashboard.putNumber( "Ycoord" , ycoord);

SmartDashboard.putString( "Data" , data );

}

else

SmartDashboard.putBoolean( "present" , false );

SmartDashboard.putNumber( "size" , blocks.size());//push to dashboard how many targets are detected

}

build.gradle...

plugins {

id "java"

id "com.kauailabs.first.GradleRIO" version "2020.3.2.1"

}

sourceCompatibility = JavaVersion.VERSION_11

targetCompatibility = JavaVersion.VERSION_11

def ROBOT_MAIN_CLASS = "frc.robot.Main"

// Define my targets (RoboRIO) and artifacts (deployable files)

// This is added by GradleRIO's backing project EmbeddedTools.

deploy {

targets {

vmxpi("roborio") {

// Team number is loaded either from the .wpilib/wpilib_preferences.json

// or from command line. If not found an exception will be thrown.

// You can use getTeamOrDefault(team) instead of getTeamNumber if you

// want to store a team number in this file.

team = frc.getTeamNumber()

}

artifacts {

frcJavaArtifact('frcJava') {

targets << "roborio"

// Debug can be overridden by command line, for use with VSCode

debug = frc.getDebugOrDefault(false)

}

// Built in artifact to deploy arbitrary files to the roboRIO.

fileTreeArtifact('frcStaticFileDeploy') {

// The directory below is the local directory to deploy

files = fileTree(dir: 'src/main/deploy')

// Deploy to RoboRIO target, into /home/lvuser/deploy

targets << "roborio"

directory = '/home/lvuser/deploy'

}

repositories {

maven { url 'https://nexus.otake.pw/repository/maven-public/' }

}

// Set this to true to enable desktop support.

def includeDesktopSupport = false

// Defining my dependencies. In this case, WPILib (+ friends), and vendor libraries.

// Also defines JUnit 4.

dependencies {

implementation wpi.deps.wpilib()

nativeZip wpi.deps.wpilibJni(wpi.platforms.raspbian)

nativeDesktopZip wpi.deps.wpilibJni(wpi.platforms.desktop)

implementation wpi.deps.vendor.java()

nativeZip wpi.deps.vendor.jni(wpi.platforms.raspbian)

nativeDesktopZip wpi.deps.vendor.jni(wpi.platforms.desktop)

implementation 'pw.otake.pseudoresonance:pixy2-java-api:1.4'

testImplementation 'junit:junit:4.12'

// Enable simulation gui support. Must check the box in vscode to enable support

// upon debugging

simulation wpi.deps.sim.gui(wpi.platforms.desktop, false)

}

// Setting up my Jar File. In this case, adding all libraries into the main jar ('fat jar')

// in order to make them all available at runtime. Also adding the manifest so WPILib

// knows where to look for our Robot Class.

jar {

from { configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it) } }

manifest edu.wpi.first.gradlerio.GradleRIOPlugin.javaManifest(ROBOT_MAIN_CLASS)

}

Scott Libert

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Jul 1, 2020, 10:55:34 PM7/1/20

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> As for the SPI, I have not uploaded our code to git but will post it below.

Thanks, I took a quick look and found the SPILink source code, it does appear to be using SPI.Port.kOnboardCS0. That should work.

Can you run it again and see if the output in the log looks any different? The one that you sent isn't giving us many clues, perhaps another run might yield more info.

> Is there a test you know of that I could do to easily ensure I have SPI set up and working?

If you have a navX-MXP, you can connect the SPI port pins to the RoboRIO Onboard SPI port, and use the "Data Monitor" example code (change the port passed to the AHRS class constructor to SPI.Port.kOnboardCS0 to match what SPILink is doing) and see if that works. That's the test case that we use to verify WPI Library SPI support on VMX-pi here in our labs. Link to Data Monitor Example page: https://pdocs.kauailabs.com/navx-mxp/examples/data-monitor/

Hope that helps,

- scott

jrothr...@hdsd.org

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Jul 1, 2020, 11:09:18 PM7/1/20

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Scott,

Thank you. I do not have a Navx MXP here, but I am going in to begin cleaning my classroom tomorrow, so I may be able to grab one (if we did not bury it when we cleaned up the shop).

I also tried using the MXP port, but that gave the same results.

I tried to get a more verbose log by selecting Detail Tags. Here it is below. I started from a reboot (hence the bad ping results in the beginning).

~Jacob

<TagVersion>1 <time> 00.000 <count> 1 <flags> 2 <Code> 44002 <details> Ping Results: link-bad, DS radio(.4)-bad, robot radio(.1)-bad, roboRIO(.2)-bad, FMS-bad FRC: Driver Station ping status has changed. <location> Driver Station <stack>

<TagVersion>1 <time> 00.000 <message> VMX HAL: pigpio library version 69 opened.

<TagVersion>1 <time> 00.000 <message> VMX HAL: SPI Aux Channel 2 opened with baudrate of 4000000.

<TagVersion>1 <time> 00.000 <message> Retrying Read....

<TagVersion>1 <time> 00.000 <message> VMX HAL: Error reading from bank 0, address 0, length 4.

<TagVersion>1 <time> 00.000 <message> Read Aborted!

<TagVersion>1 <time> 00.000 <message> VMX HAL: Established communication with VMX-pi model 0x32, hardware rev 60, firmware version 3.0.411

<TagVersion>1 <time> 00.000 <message> VMX HAL: Acquired navX-Sensor configuration.

<TagVersion>1 <time> 00.000 <message> VMX HAL: Library version 1.1.225

<TagVersion>1 <time> 00.000 <message> Set VMX CAN Mode to NORMAL.

<TagVersion>1 <time> 00.000 <message> Server Running...

<TagVersion>1 <time> 00.000 <message> ********** Robot program starting **********

<TagVersion>1 <time> 00.000 <message> Default simulationInit() method... Override me!

<TagVersion>1 <time> 00.000 <message> Default disabledInit() method... Override me!

<TagVersion>1 <time> 00.000 <message> Default disabledPeriodic() method... Override me!

<TagVersion>1 <time> 00.000 <message> Default robotPeriodic() method... Override me!

<TagVersion>1 <time> 00.000 <message> Watchdog not fed within 0.020000s

<TagVersion>1 <time> 00.000 <message> Default simulationPeriodic() method... Override me!

<TagVersion>1 <time> 00.000 <count> 1 <flags> 0 <Code> 1 <details> Loop time of 0.02s overrun

<location> edu.wpi.first.wpilibj.IterativeRobotBase.printLoopOverrunMessage(IterativeRobotBase.java:309) <stack>

<TagVersion>1 <time> 00.000 <message> Warning at edu.wpi.first.wpilibj.IterativeRobotBase.printLoopOverrunMessage(IterativeRobotBase.java:309): Loop time of 0.02s overrun

<TagVersion>1 <time> 00.000 <message> SmartDashboard.updateValues(): 0.008132s

<TagVersion>1 <time> 00.000 <message> disabledInit(): 0.001855s

<TagVersion>1 <time> 00.000 <message> disablePeriodic(): 0.000379s

<TagVersion>1 <time> 00.000 <message> robotPeriodic(): 0.000101s

<TagVersion>1 <time> 00.000 <message> LiveWindow.updateValues(): 0.011141s

<TagVersion>1 <time> 00.000 <message> Shuffleboard.update(): 0.000037s

<TagVersion>1 <time> 00.000 <message> simulationPeriodic(): 0.053747s

<TagVersion>1 <time> 00.000 <count> 1 <flags> 2 <Code> 44003 <details> FRC: No robot code is currently running. <location> Driver Station <stack>

<TagVersion>1 <time> 00.000 <count> 1 <flags> 2 <Code> 44002 <details> Ping Results: link-bad, DS radio(.4)-bad, robot radio(.1)-bad, roboRIO(.2)-GOOD, FMS-bad FRC: Driver Station ping status has changed. <location> Driver Station <stack>

<TagVersion>1 <time> 00.000 <message> NT: server: client CONNECTED: 10.67.62.11 port 64778

<TagVersion>1 <time> 00.000 <message> Default teleopInit() method... Override me!

<TagVersion>1 <time> 00.000 <message> Thu Jun 25 11:17:34 2020 - WARN : Error deactivating Resource type 9, index 0

<TagVersion>1 <time> 00.000 <message> (VMXIO.cpp [1214])

<TagVersion>1 <time> 00.000 <message> 2020-06-25 11:17:34 spiOpen: bad baud (2000)

<TagVersion>1 <time> 00.000 <message> Watchdog not fed within 0.020000s

<TagVersion>1 <time> 00.000 <count> 1 <flags> 0 <Code> 1 <details> Loop time of 0.02s overrun

<location> edu.wpi.first.wpilibj.IterativeRobotBase.printLoopOverrunMessage(IterativeRobotBase.java:309) <stack>

<TagVersion>1 <time> 00.000 <message> Warning at edu.wpi.first.wpilibj.IterativeRobotBase.printLoopOverrunMessage(IterativeRobotBase.java:309): Loop time of 0.02s overrun

<TagVersion>1 <time> 00.000 <message> teleopPeriodic(): 5.023429s

<TagVersion>1 <time> 00.000 <message> SmartDashboard.updateValues(): 0.000027s

<TagVersion>1 <time> 00.000 <message> robotPeriodic(): 0.000010s

<TagVersion>1 <time> 00.000 <message> LiveWindow.updateValues(): 0.000022s

<TagVersion>1 <time> 00.000 <message> Shuffleboard.update(): 0.000010s

<TagVersion>1 <time> 00.000 <message> simulationPeriodic(): 0.000004s

<TagVersion>1 <time> 00.000 <message> teleopInit(): 0.000276s

<TagVersion>1 <time> 00.000 <message> 2020-06-25 11:17:39 spiOpen: bad baud (2000)

<TagVersion>1 <time> 00.000 <message> Thu Jun 25 11:17:39 2020 - WARN : Error deactivating Resource type 9, index 0

<TagVersion>1 <time> 00.000 <message> (VMXIO.cpp [1214])

<TagVersion>1 <time> 00.000 <count> 1 <flags> 1 <Code> 1 <details> Unhandled exception: edu.wpi.first.hal.util.UncleanStatusException: Code: -20013. Error configuring physical resource <location> io.github.pseudoresonance.pixy2api.links.SPILink.open(SPILink.java:65) <stack> at edu.wpi.first.hal.SPIJNI.spiInitialize(Native Method)

at edu.wpi.first.wpilibj.SPI.<init>(SPI.java:48)

at io.github.pseudoresonance.pixy2api.links.SPILink.open(SPILink.java:65)

at io.github.pseudoresonance.pixy2api.Pixy2.init(Pixy2.java:125)

at frc.robot.Robot.teleopPeriodic(Robot.java:52)

at edu.wpi.first.wpilibj.IterativeRobotBase.loopFunc(IterativeRobotBase.java:267)

at edu.wpi.first.wpilibj.TimedRobot.startCompetition(TimedRobot.java:86)

at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:276)

at edu.wpi.first.wpilibj.RobotBase.startRobot(RobotBase.java:348)

at frc.robot.Main.main(Main.java:27)

<TagVersion>1 <time> 00.000 <message> Error at io.github.pseudoresonance.pixy2api.links.SPILink.open(SPILink.java:65): Unhandled exception: edu.wpi.first.hal.util.UncleanStatusException: Code: -20013. Error configuring physical resource

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.hal.SPIJNI.spiInitialize(Native Method)

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.wpilibj.SPI.<init>(SPI.java:48)

<TagVersion>1 <time> 00.000 <message> at io.github.pseudoresonance.pixy2api.links.SPILink.open(SPILink.java:65)

<TagVersion>1 <time> 00.000 <message> at io.github.pseudoresonance.pixy2api.Pixy2.init(Pixy2.java:125)

<TagVersion>1 <time> 00.000 <message> at frc.robot.Robot.teleopPeriodic(Robot.java:52)

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.wpilibj.IterativeRobotBase.loopFunc(IterativeRobotBase.java:267)

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.wpilibj.TimedRobot.startCompetition(TimedRobot.java:86)

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:276)

<TagVersion>1 <time> 00.000 <message> at edu.wpi.first.wpilibj.RobotBase.startRobot(RobotBase.java:348)

<TagVersion>1 <time> 00.000 <message> at frc.robot.Main.main(Main.java:27)

<TagVersion>1 <time> 00.000 <count> 1 <flags> 0 <Code> 1 <details> Robots should not quit, but yours did! <location> edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:291) <stack>

<TagVersion>1 <time> 00.000 <message> Warning at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:291): Robots should not quit, but yours did!

<TagVersion>1 <time> 00.000 <count> 1 <flags> 1 <Code> 1 <details> The startCompetition() method (or methods called by it) should have handled the exception above. <location> edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:293) <stack>

<TagVersion>1 <time> 00.000 <message> Error at edu.wpi.first.wpilibj.RobotBase.runRobot(RobotBase.java:293): The startCompetition() method (or methods called by it) should have handled the exception above.