Add code for a practice defense bot

We want to use the 2nd robot drivetrain as a defense bot to use in drive
practice, this commit adds the folder for that robot.

Signed-off-by: Maxwell Henderson <mxwhenderson@gmail.com>
Change-Id: I8d379c8793dffe3248f1ecef83fe18040c7e0e77
diff --git a/y2024_defense/wpilib_interface.cc b/y2024_defense/wpilib_interface.cc
new file mode 100644
index 0000000..7cecb21
--- /dev/null
+++ b/y2024_defense/wpilib_interface.cc
@@ -0,0 +1,381 @@
+#include <unistd.h>
+
+#include <array>
+#include <chrono>
+#include <cinttypes>
+#include <cmath>
+#include <cstdio>
+#include <cstring>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <thread>
+
+#include "ctre/phoenix/CANifier.h"
+
+#include "frc971/wpilib/ahal/AnalogInput.h"
+#include "frc971/wpilib/ahal/Counter.h"
+#include "frc971/wpilib/ahal/DigitalGlitchFilter.h"
+#include "frc971/wpilib/ahal/DriverStation.h"
+#include "frc971/wpilib/ahal/Encoder.h"
+#include "frc971/wpilib/ahal/Servo.h"
+#include "frc971/wpilib/ahal/TalonFX.h"
+#include "frc971/wpilib/ahal/VictorSP.h"
+#undef ERROR
+
+#include "ctre/phoenix/cci/Diagnostics_CCI.h"
+#include "ctre/phoenix6/TalonFX.hpp"
+
+#include "aos/commonmath.h"
+#include "aos/containers/sized_array.h"
+#include "aos/events/event_loop.h"
+#include "aos/events/shm_event_loop.h"
+#include "aos/init.h"
+#include "aos/logging/logging.h"
+#include "aos/realtime.h"
+#include "aos/time/time.h"
+#include "aos/util/log_interval.h"
+#include "aos/util/phased_loop.h"
+#include "aos/util/wrapping_counter.h"
+#include "frc971/autonomous/auto_mode_generated.h"
+#include "frc971/can_configuration_generated.h"
+#include "frc971/control_loops/drivetrain/drivetrain_can_position_generated.h"
+#include "frc971/control_loops/drivetrain/drivetrain_position_generated.h"
+#include "frc971/input/robot_state_generated.h"
+#include "frc971/queues/gyro_generated.h"
+#include "frc971/wpilib/ADIS16448.h"
+#include "frc971/wpilib/buffered_pcm.h"
+#include "frc971/wpilib/buffered_solenoid.h"
+#include "frc971/wpilib/can_drivetrain_writer.h"
+#include "frc971/wpilib/can_sensor_reader.h"
+#include "frc971/wpilib/dma.h"
+#include "frc971/wpilib/drivetrain_writer.h"
+#include "frc971/wpilib/encoder_and_potentiometer.h"
+#include "frc971/wpilib/falcon.h"
+#include "frc971/wpilib/joystick_sender.h"
+#include "frc971/wpilib/logging_generated.h"
+#include "frc971/wpilib/loop_output_handler.h"
+#include "frc971/wpilib/pdp_fetcher.h"
+#include "frc971/wpilib/sensor_reader.h"
+#include "frc971/wpilib/wpilib_robot_base.h"
+#include "y2024_defense/constants.h"
+
+DEFINE_bool(ctre_diag_server, false,
+            "If true, enable the diagnostics server for interacting with "
+            "devices on the CAN bus using Phoenix Tuner");
+
+using ::aos::monotonic_clock;
+using ::frc971::CANConfiguration;
+using ::y2024_defense::constants::Values;
+
+using frc971::control_loops::drivetrain::CANPosition;
+using frc971::wpilib::Falcon;
+
+using std::make_unique;
+
+namespace y2024_defense {
+namespace wpilib {
+namespace {
+
+constexpr double kMaxBringupPower = 12.0;
+
+double drivetrain_velocity_translate(double in) {
+  return (((1.0 / in) / Values::kDrivetrainCyclesPerRevolution()) *
+          (2.0 * M_PI)) *
+         Values::kDrivetrainEncoderRatio() *
+         control_loops::drivetrain::kWheelRadius;
+}
+
+constexpr double kMaxFastEncoderPulsesPerSecond = std::max({
+    Values::kMaxDrivetrainEncoderPulsesPerSecond(),
+});
+static_assert(kMaxFastEncoderPulsesPerSecond <= 1300000,
+              "fast encoders are too fast");
+
+}  // namespace
+
+// Class to send position messages with sensor readings to our loops.
+class SensorReader : public ::frc971::wpilib::SensorReader {
+ public:
+  SensorReader(::aos::ShmEventLoop *event_loop,
+               std::shared_ptr<const Values> values)
+      : ::frc971::wpilib::SensorReader(event_loop),
+        values_(std::move(values)),
+        auto_mode_sender_(
+            event_loop->MakeSender<::frc971::autonomous::AutonomousMode>(
+                "/autonomous")),
+        drivetrain_position_sender_(
+            event_loop
+                ->MakeSender<::frc971::control_loops::drivetrain::Position>(
+                    "/drivetrain")),
+        gyro_sender_(event_loop->MakeSender<::frc971::sensors::GyroReading>(
+            "/drivetrain")) {
+    // Set to filter out anything shorter than 1/4 of the minimum pulse width
+    // we should ever see.
+    UpdateFastEncoderFilterHz(kMaxFastEncoderPulsesPerSecond);
+    event_loop->SetRuntimeAffinity(aos::MakeCpusetFromCpus({0}));
+  }
+
+  void Start() override { AddToDMA(&imu_yaw_rate_reader_); }
+
+  // Auto mode switches.
+  void set_autonomous_mode(int i, ::std::unique_ptr<frc::DigitalInput> sensor) {
+    autonomous_modes_.at(i) = ::std::move(sensor);
+  }
+
+  void set_yaw_rate_input(::std::unique_ptr<frc::DigitalInput> sensor) {
+    imu_yaw_rate_input_ = ::std::move(sensor);
+    imu_yaw_rate_reader_.set_input(imu_yaw_rate_input_.get());
+  }
+
+  void RunIteration() override {
+    superstructure_reading_->Set(true);
+    {
+      {
+        auto builder = drivetrain_position_sender_.MakeBuilder();
+        frc971::control_loops::drivetrain::Position::Builder
+            drivetrain_builder =
+                builder
+                    .MakeBuilder<frc971::control_loops::drivetrain::Position>();
+        drivetrain_builder.add_left_encoder(
+            constants::Values::DrivetrainEncoderToMeters(
+                drivetrain_left_encoder_->GetRaw()));
+        drivetrain_builder.add_left_speed(drivetrain_velocity_translate(
+            drivetrain_left_encoder_->GetPeriod()));
+
+        drivetrain_builder.add_right_encoder(
+            -constants::Values::DrivetrainEncoderToMeters(
+                drivetrain_right_encoder_->GetRaw()));
+        drivetrain_builder.add_right_speed(-drivetrain_velocity_translate(
+            drivetrain_right_encoder_->GetPeriod()));
+
+        builder.CheckOk(builder.Send(drivetrain_builder.Finish()));
+      }
+
+      {
+        auto builder = gyro_sender_.MakeBuilder();
+        ::frc971::sensors::GyroReading::Builder gyro_reading_builder =
+            builder.MakeBuilder<::frc971::sensors::GyroReading>();
+        // +/- 2000 deg / sec
+        constexpr double kMaxVelocity = 4000;  // degrees / second
+        constexpr double kVelocityRadiansPerSecond =
+            kMaxVelocity / 360 * (2.0 * M_PI);
+
+        // Only part of the full range is used to prevent being 100% on or off.
+        constexpr double kScaledRangeLow = 0.1;
+        constexpr double kScaledRangeHigh = 0.9;
+
+        constexpr double kPWMFrequencyHz = 200;
+        double velocity_duty_cycle =
+            imu_yaw_rate_reader_.last_width() * kPWMFrequencyHz;
+
+        constexpr double kDutyCycleScale =
+            1 / (kScaledRangeHigh - kScaledRangeLow);
+        // scale from 0.1 - 0.9 to 0 - 1
+        double rescaled_velocity_duty_cycle =
+            (velocity_duty_cycle - kScaledRangeLow) * kDutyCycleScale;
+
+        if (!std::isnan(rescaled_velocity_duty_cycle)) {
+          gyro_reading_builder.add_velocity(
+              (rescaled_velocity_duty_cycle - 0.5) * kVelocityRadiansPerSecond);
+        }
+        builder.CheckOk(builder.Send(gyro_reading_builder.Finish()));
+      }
+
+      {
+        auto builder = auto_mode_sender_.MakeBuilder();
+
+        uint32_t mode = 0;
+        for (size_t i = 0; i < autonomous_modes_.size(); ++i) {
+          if (autonomous_modes_[i] && autonomous_modes_[i]->Get()) {
+            mode |= 1 << i;
+          }
+        }
+
+        auto auto_mode_builder =
+            builder.MakeBuilder<frc971::autonomous::AutonomousMode>();
+
+        auto_mode_builder.add_mode(mode);
+
+        builder.CheckOk(builder.Send(auto_mode_builder.Finish()));
+      }
+    }
+  }
+
+  std::shared_ptr<frc::DigitalOutput> superstructure_reading_;
+
+  void set_superstructure_reading(
+      std::shared_ptr<frc::DigitalOutput> superstructure_reading) {
+    superstructure_reading_ = superstructure_reading;
+  }
+
+ private:
+  std::shared_ptr<const Values> values_;
+
+  aos::Sender<frc971::autonomous::AutonomousMode> auto_mode_sender_;
+  aos::Sender<frc971::control_loops::drivetrain::Position>
+      drivetrain_position_sender_;
+  ::aos::Sender<::frc971::sensors::GyroReading> gyro_sender_;
+
+  std::array<std::unique_ptr<frc::DigitalInput>, 2> autonomous_modes_;
+
+  std::unique_ptr<frc::DigitalInput> imu_yaw_rate_input_;
+
+  frc971::wpilib::DMAPulseWidthReader imu_yaw_rate_reader_;
+};
+
+class WPILibRobot : public ::frc971::wpilib::WPILibRobotBase {
+ public:
+  ::std::unique_ptr<frc::Encoder> make_encoder(int index) {
+    return make_unique<frc::Encoder>(10 + index * 2, 11 + index * 2, false,
+                                     frc::Encoder::k4X);
+  }
+
+  void Run() override {
+    std::shared_ptr<const Values> values =
+        std::make_shared<const Values>(constants::MakeValues());
+
+    aos::FlatbufferDetachedBuffer<aos::Configuration> config =
+        aos::configuration::ReadConfig("aos_config.json");
+
+    // Thread 1.
+    ::aos::ShmEventLoop joystick_sender_event_loop(&config.message());
+    ::frc971::wpilib::JoystickSender joystick_sender(
+        &joystick_sender_event_loop);
+    AddLoop(&joystick_sender_event_loop);
+
+    // Thread 2.
+    ::aos::ShmEventLoop pdp_fetcher_event_loop(&config.message());
+    ::frc971::wpilib::PDPFetcher pdp_fetcher(&pdp_fetcher_event_loop);
+    AddLoop(&pdp_fetcher_event_loop);
+
+    // Thread 3.
+    ::aos::ShmEventLoop sensor_reader_event_loop(&config.message());
+    SensorReader sensor_reader(&sensor_reader_event_loop, values);
+    std::shared_ptr<frc::DigitalOutput> superstructure_reading =
+        make_unique<frc::DigitalOutput>(25);
+
+    sensor_reader.set_pwm_trigger(true);
+    sensor_reader.set_drivetrain_left_encoder(make_encoder(1));
+    sensor_reader.set_drivetrain_right_encoder(make_encoder(0));
+    sensor_reader.set_superstructure_reading(superstructure_reading);
+    sensor_reader.set_yaw_rate_input(make_unique<frc::DigitalInput>(0));
+
+    AddLoop(&sensor_reader_event_loop);
+
+    // Thread 4.
+    std::vector<ctre::phoenix6::BaseStatusSignal *> signals_registry;
+
+    std::shared_ptr<Falcon> right_front = std::make_shared<Falcon>(
+        1, true, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+    std::shared_ptr<Falcon> right_back = std::make_shared<Falcon>(
+        2, true, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+    std::shared_ptr<Falcon> right_under = std::make_shared<Falcon>(
+        3, true, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+    std::shared_ptr<Falcon> left_front = std::make_shared<Falcon>(
+        4, false, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+    std::shared_ptr<Falcon> left_back = std::make_shared<Falcon>(
+        5, false, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+    std::shared_ptr<Falcon> left_under = std::make_shared<Falcon>(
+        6, false, "Drivetrain Bus", &signals_registry,
+        constants::Values::kDrivetrainStatorCurrentLimit(),
+        constants::Values::kDrivetrainSupplyCurrentLimit());
+
+    // Setting up CAN.
+    if (!FLAGS_ctre_diag_server) {
+      c_Phoenix_Diagnostics_SetSecondsToStart(-1);
+      c_Phoenix_Diagnostics_Dispose();
+    }
+
+    // Creating list of falcons for CANSensorReader
+    std::vector<std::shared_ptr<Falcon>> falcons;
+    for (auto falcon : {right_front, right_back, right_under, left_front,
+                        left_back, left_under}) {
+      falcons.push_back(falcon);
+    }
+
+    ctre::phoenix::platform::can::CANComm_SetRxSchedPriority(
+        constants::Values::kDrivetrainRxPriority, true, "Drivetrain Bus");
+    ctre::phoenix::platform::can::CANComm_SetTxSchedPriority(
+        constants::Values::kDrivetrainTxPriority, true, "Drivetrain Bus");
+
+    ::aos::ShmEventLoop can_sensor_reader_event_loop(&config.message());
+    can_sensor_reader_event_loop.set_name("CANSensorReader");
+
+    aos::Sender<CANPosition> can_position_sender =
+        can_sensor_reader_event_loop.MakeSender<CANPosition>("/drivetrain");
+
+    frc971::wpilib::CANSensorReader can_sensor_reader(
+        &can_sensor_reader_event_loop, std::move(signals_registry), falcons,
+        [falcons, &can_position_sender](ctre::phoenix::StatusCode status) {
+          auto builder = can_position_sender.MakeBuilder();
+          aos::SizedArray<flatbuffers::Offset<frc971::control_loops::CANFalcon>,
+                          6>
+              flatbuffer_falcons;
+
+          for (auto falcon : falcons) {
+            falcon->SerializePosition(
+                builder.fbb(), control_loops::drivetrain::kHighOutputRatio);
+            std::optional<flatbuffers::Offset<frc971::control_loops::CANFalcon>>
+                falcon_offset = falcon->TakeOffset();
+
+            CHECK(falcon_offset.has_value());
+
+            flatbuffer_falcons.push_back(falcon_offset.value());
+          }
+
+          auto falcons_list =
+              builder.fbb()
+                  ->CreateVector<
+                      flatbuffers::Offset<frc971::control_loops::CANFalcon>>(
+                      flatbuffer_falcons);
+
+          frc971::control_loops::drivetrain::CANPosition::Builder
+              can_position_builder = builder.MakeBuilder<
+                  frc971::control_loops::drivetrain::CANPosition>();
+
+          can_position_builder.add_falcons(falcons_list);
+          can_position_builder.add_timestamp(falcons.front()->GetTimestamp());
+          can_position_builder.add_status(static_cast<int>(status));
+
+          builder.CheckOk(builder.Send(can_position_builder.Finish()));
+        });
+
+    AddLoop(&can_sensor_reader_event_loop);
+
+    // Thread 5.
+    ::aos::ShmEventLoop can_drivetrain_writer_event_loop(&config.message());
+    can_drivetrain_writer_event_loop.set_name("CANDrivetrainWriter");
+
+    frc971::wpilib::CANDrivetrainWriter can_drivetrain_writer(
+        &can_drivetrain_writer_event_loop);
+
+    can_drivetrain_writer.set_falcons({right_front, right_back, right_under},
+                                      {left_front, left_back, left_under});
+
+    can_drivetrain_writer_event_loop.MakeWatcher(
+        "/roborio", [&can_drivetrain_writer](
+                        const frc971::CANConfiguration &configuration) {
+          can_drivetrain_writer.HandleCANConfiguration(configuration);
+        });
+
+    AddLoop(&can_drivetrain_writer_event_loop);
+
+    RunLoops();
+  }
+};
+
+}  // namespace wpilib
+}  // namespace y2024_defense
+
+AOS_ROBOT_CLASS(::y2024_defense::wpilib::WPILibRobot);