diff --git a/frc971/control_loops/DriveTrain.cc b/frc971/control_loops/DriveTrain.cc
new file mode 100644
index 0000000..b627cc0
--- /dev/null
+++ b/frc971/control_loops/DriveTrain.cc
@@ -0,0 +1,298 @@
+#include "frc971/control_loops/DriveTrain.h"
+
+#include <stdio.h>
+#include <sched.h>
+#include <cmath>
+
+#include "aos/aos_core.h"
+#include "aos/common/logging/logging.h"
+#include "aos/common/queue.h"
+#include "frc971/control_loops/DriveTrain.mat"
+#include "frc971/control_loops/DriveTrain.q.h"
+#include "frc971/queues/GyroAngle.q.h"
+#include "frc971/queues/Piston.q.h"
+
+using frc971::sensors::gyro;
+
+namespace frc971 {
+namespace control_loops {
+
+// Width of the robot.
+const double width = 22.0 / 100.0 * 2.54;
+
+class DrivetrainMotorsSS : public MatrixClass {
+ public:
+  DrivetrainMotorsSS (void) {
+    MATRIX_INIT;
+    _offset = 0;
+    _integral_offset = 0;
+    _left_goal = 0.0;
+    _right_goal = 0.0;
+    _raw_left = 0.0;
+    _raw_right = 0.0;
+  }
+  void SetGoal(double left, double left_velocity, double right, double right_velocity) {
+    _left_goal = left;
+    _right_goal = right;
+    R << left + _integral_offset * width / 2.0, left_velocity, right - _integral_offset * width / 2.0, right_velocity;
+  }
+  void SetRawPosition(double left, double right) {
+    _raw_right = right;
+    _raw_left = left;
+    Y << left + _offset + _integral_offset, right - _offset + _integral_offset;
+  }
+  void SetPosition(double left, double right, double gyro, bool control_loop_driving) {
+    // Decay the offset quickly because this gyro is great.
+    _offset = (0.25) * (right - left - gyro * width) / 2.0 + 0.75 * _offset;
+    const double angle_error = (_right_goal - _left_goal) / width - (_raw_right - _offset - _raw_left - _offset) / width;
+    if (!control_loop_driving) {
+      _integral_offset = 0.0;
+    } else if (std::abs(angle_error) < M_PI / 10.0) {
+      _integral_offset -= angle_error * 0.010;
+    } else {
+      _integral_offset *= 0.97;
+    }
+    _gyro = gyro;
+    SetRawPosition(left, right);
+    LOG(DEBUG, "Left %f->%f Right %f->%f Gyro %f aerror %f ioff %f\n", left + _offset, _left_goal, right - _offset, _right_goal, gyro, angle_error, _integral_offset);
+  }
+  double UnDeadband(double value) {
+    const double positive_deadband_power = 0.15 * 12;
+    const double negative_deadband_power = 0.09 * 12;
+    if (value > 0) {
+      value += positive_deadband_power;
+    }
+    if (value < 0) {
+      value -= negative_deadband_power;
+    }
+    if (value > 12.0) {
+      value = 12.0;
+    }
+    if (value < -12.0) {
+      value = -12.0;
+    }
+    return value;
+  }
+
+  void SendMotors(Drivetrain::Output *status) {
+    status->left_voltage = UnDeadband(U[0]);
+    status->right_voltage = UnDeadband(U[1]);
+  }
+  void PrintMotors() const {
+    // LOG(DEBUG, "Left Power %f Right Power %f lg %f rg %f le %f re %f gyro %f\n", U[0], U[1], R[0], R[2], Y[0], Y[1], _gyro);
+    LOG(DEBUG, "lg %f rg %f le %f re %f gyro %f off %f\n", R[0], R[2], Y[0], Y[1], _gyro * 180.0 / M_PI, _offset);
+  }
+
+ private:
+  double _integral_offset;
+  double _offset;
+  double _gyro;
+  double _left_goal;
+  double _right_goal;
+  double _raw_left;
+  double _raw_right;
+};
+
+class DrivetrainMotorsOL {
+ public:
+  DrivetrainMotorsOL() {
+    _old_wheel = 0.0;
+    quick_stop_accumulator = 0.0;
+    _wheel = 0.0;
+    _throttle = 0.0;
+    _quickturn = false;
+    _highgear = true;
+    _neg_inertia_accumulator = 0.0;
+    _left_pwm = 0.0;
+    _right_pwm = 0.0;
+  }
+  void SetGoal(double wheel, double throttle, bool quickturn, bool highgear) {
+    _wheel = wheel;
+    _throttle = throttle;
+    _quickturn = quickturn;
+    _highgear = highgear;
+    _left_pwm = 0.0;
+    _right_pwm = 0.0;
+  }
+  void Update(void) {
+    double overPower;
+    float sensitivity = 1.7;
+    float angular_power;
+    float linear_power;
+    double wheel;
+
+    double neg_inertia = _wheel - _old_wheel;
+    _old_wheel = _wheel;
+
+    double wheelNonLinearity;
+    if (_highgear) {
+      wheelNonLinearity = 0.7;  // used to be csvReader->TURN_NONLIN_HIGH
+      // Apply a sin function that's scaled to make it feel better.
+      const double angular_range = M_PI / 2.0 * wheelNonLinearity;
+      wheel = sin(angular_range * _wheel) / sin(angular_range);
+      wheel = sin(angular_range * _wheel) / sin(angular_range);
+    } else {
+      wheelNonLinearity = 0.4;  // used to be csvReader->TURN_NONLIN_LOW
+      // Apply a sin function that's scaled to make it feel better.
+      const double angular_range = M_PI / 2.0 * wheelNonLinearity;
+      wheel = sin(angular_range * _wheel) / sin(angular_range);
+      wheel = sin(angular_range * _wheel) / sin(angular_range);
+      wheel = sin(angular_range * _wheel) / sin(angular_range);
+    }
+
+    double neg_inertia_scalar;
+    if (_highgear) {
+      neg_inertia_scalar = 20.0;  // used to be csvReader->NEG_INTERTIA_HIGH
+      sensitivity = 1.22; // used to be csvReader->SENSE_HIGH
+    } else {
+      if (wheel * neg_inertia > 0) {
+        neg_inertia_scalar = 16;  // used to be csvReader->NEG_INERTIA_LOW_MORE
+      } else {
+        if (fabs(wheel) > 0.65) {
+          neg_inertia_scalar = 16;  // used to be csvReader->NEG_INTERTIA_LOW_LESS_EXT
+        } else {
+          neg_inertia_scalar = 5;  // used to be csvReader->NEG_INTERTIA_LOW_LESS
+        }
+      }
+      sensitivity = 1.24;  // used to be csvReader->SENSE_LOW
+
+      if (fabs(_throttle) > 0.1) {  // used to be csvReader->SENSE_CUTTOFF
+        sensitivity = 1 - (1 - sensitivity) / fabs(_throttle);
+      }
+    }
+    double neg_inertia_power = neg_inertia * neg_inertia_scalar;
+    _neg_inertia_accumulator += neg_inertia_power;
+
+    wheel = wheel + _neg_inertia_accumulator;
+    if (_neg_inertia_accumulator > 1) {
+      _neg_inertia_accumulator -= 1;
+    } else if (_neg_inertia_accumulator < -1) {
+      _neg_inertia_accumulator += 1;
+    } else {
+      _neg_inertia_accumulator = 0;
+    }
+
+    linear_power = _throttle;
+
+    const double quickstop_scalar = 6;
+    if (_quickturn) {
+      double qt_angular_power = wheel;
+      const double alpha = 0.1;
+      if (fabs(linear_power) < 0.2) {
+        if (qt_angular_power > 1) qt_angular_power = 1.0;
+        if (qt_angular_power < -1) qt_angular_power = -1.0;
+      } else {
+        qt_angular_power = 0.0;
+      }
+      quick_stop_accumulator = (1 - alpha) * quick_stop_accumulator + alpha * qt_angular_power * quickstop_scalar;
+      overPower = 1.0;
+      if (_highgear) {
+        sensitivity = 1.0;
+      } else {
+        sensitivity = 1.0;
+      }
+      angular_power = wheel;
+    } else {
+      overPower = 0.0;
+      angular_power = fabs(_throttle) * wheel * sensitivity;
+      angular_power -= quick_stop_accumulator;
+      if (quick_stop_accumulator > 1) {
+        quick_stop_accumulator -= 1;
+      } else if (quick_stop_accumulator < -1) {
+        quick_stop_accumulator += 1;
+      } else {
+        quick_stop_accumulator = 0;
+      }
+    }
+
+    _right_pwm = _left_pwm = linear_power;
+    _left_pwm += angular_power;
+    _right_pwm -= angular_power;
+
+    if (_left_pwm > 1.0) {
+      _right_pwm -= overPower*(_left_pwm - 1.0);
+      _left_pwm = 1.0;
+    } else if (_right_pwm > 1.0) {
+      _left_pwm -= overPower*(_right_pwm - 1.0);
+      _right_pwm = 1.0;
+    } else if (_left_pwm < -1.0) {
+      _right_pwm += overPower*(-1.0 - _left_pwm);
+      _left_pwm = -1.0;
+    } else if (_right_pwm < -1.0) {
+      _left_pwm += overPower*(-1.0 - _right_pwm);
+      _right_pwm = -1.0;
+    }
+  }
+
+  void SendMotors(Drivetrain::Output *output) {
+    LOG(DEBUG, "left pwm: %f right pwm: %f wheel: %f throttle: %f, qa %f\n",
+        _left_pwm, _right_pwm, _wheel, _throttle, quick_stop_accumulator);
+    output->left_voltage = _left_pwm * 12.0;
+    output->right_voltage = _right_pwm * 12.0;
+    if (_highgear) {
+      shifters.MakeWithBuilder().set(false).Send();
+    } else {
+      shifters.MakeWithBuilder().set(true).Send();
+    }
+  }
+
+ private:
+  double _old_wheel;
+  double _wheel;
+  double _throttle;
+  bool _quickturn;
+  bool _highgear;
+  double _neg_inertia_accumulator;
+  double _left_pwm;
+  double _right_pwm;
+  double quick_stop_accumulator;
+};
+
+void DrivetrainLoop::RunIteration(const Drivetrain::Goal *goal,
+                                  const Drivetrain::Position *position,
+                                  Drivetrain::Output *output,
+                                  Drivetrain::Status * /*status*/) {
+  // TODO(aschuh): These should be members of the class.
+  static DrivetrainMotorsSS dt_closedloop;
+  static DrivetrainMotorsOL dt_openloop;
+
+  bool bad_pos = false;
+  if (position == NULL) {
+    LOG(WARNING, "no pos\n");
+    bad_pos = true;
+  }
+
+  double wheel = goal->steering;
+  double throttle = goal->throttle;
+  bool quickturn = goal->quickturn;
+  bool highgear = goal->highgear;
+
+  bool control_loop_driving = goal->control_loop_driving;
+  double left_goal = goal->left_goal;
+  double right_goal = goal->right_goal;
+
+  dt_closedloop.SetGoal(left_goal, 0.0, right_goal, 0.0);
+  if (!bad_pos) {
+    const double left_encoder = position->left_encoder;
+    const double right_encoder = position->right_encoder;
+    if (gyro.FetchLatest()) {
+      dt_closedloop.SetPosition(left_encoder, right_encoder,
+          gyro->angle, control_loop_driving);
+    } else {
+      dt_closedloop.SetRawPosition(left_encoder, right_encoder);
+    }
+  }
+  dt_closedloop.Update(!bad_pos, bad_pos || (output == NULL));
+  dt_openloop.SetGoal(wheel, throttle, quickturn, highgear);
+  dt_openloop.Update();
+  if (control_loop_driving) {
+    dt_closedloop.SendMotors(output);
+  } else {
+    dt_openloop.SendMotors(output);
+  }
+}
+
+}  // namespace control_loops
+}  // namespace frc971
+
+AOS_RUN_LOOP(frc971::control_loops::DrivetrainLoop)