got it so that reading usb packets reliably works "sometimes"
diff --git a/aos/common/sensors/sensor_receiver-tmpl.h b/aos/common/sensors/sensor_receiver-tmpl.h
index dc9f17d..e3840c4 100644
--- a/aos/common/sensors/sensor_receiver-tmpl.h
+++ b/aos/common/sensors/sensor_receiver-tmpl.h
@@ -6,7 +6,7 @@
 
 template<class Values>
 const time::Time SensorReceiver<Values>::kJitterDelay =
-    time::Time::InSeconds(0.0035);
+    time::Time::InSeconds(0.00225);
 // Not a multiple of kSensorSendFrequency to unwedge ourself if we hit some bug
 // where it needs to get off of that frequency to work.
 template<class Values>
@@ -185,6 +185,7 @@
         }
       }
 
+      Synchronized(goal_time + kLoopFrequency * kTestCycles);
       return true;
     }
 
@@ -197,13 +198,6 @@
   int old_count = data_.count;
   DoReceiveData();
 
-  data_.checksum = ntoh(data_.checksum);
-  if (!data_.CheckChecksum()) {
-    LOG(WARNING, "got a bad packet\n");
-    return ReceiveData();
-  }
-
-  data_.NetworkToHost();
   if (data_.count < 0) {
     LOG(FATAL, "data count overflowed. currently %"PRId32"\n", data_.count);
   }
@@ -251,6 +245,13 @@
   while (true) {
     if (socket_.Receive(this->data(), sizeof(*this->data())) ==
         sizeof(*this->data())) {
+      this->data()->checksum = ntoh(this->data()->checksum);
+      if (!this->data()->CheckChecksum()) {
+        LOG(WARNING, "got a bad packet\n");
+        continue;
+      }
+
+      this->data()->NetworkToHost();
       return;
     }
     LOG(WARNING, "received incorrect amount of data\n");
diff --git a/aos/common/sensors/sensor_receiver.h b/aos/common/sensors/sensor_receiver.h
index c829d53..9cd24e1 100644
--- a/aos/common/sensors/sensor_receiver.h
+++ b/aos/common/sensors/sensor_receiver.h
@@ -53,6 +53,8 @@
 
   // Subclasses need to implement this to read 1 set of data (blocking until it
   // is available) into data().
+  // It needs to have the correct byte order etc and not be corrupted
+  // (subclasses can check the checksum if they want).
   virtual void DoReceiveData() = 0;
 
   // Optional: if subclasses can do anything to reinitialize after there are
@@ -60,6 +62,10 @@
   // This will be called right before calling DoReceiveData() the first time.
   virtual void Reset() {}
 
+  // Optional: if subclasses want to be notified when this is first convinced
+  // that it has a good packet, they should do whatever here.
+  virtual void Synchronized(time::Time /*last_packet_ideal_time*/) {}
+
   // Returns whether the current packet looks like a good one to use.
   bool GoodPacket();
 
diff --git a/aos/common/time.cc b/aos/common/time.cc
index 995011a..75ea196 100644
--- a/aos/common/time.cc
+++ b/aos/common/time.cc
@@ -120,6 +120,9 @@
 const Time Time::operator/(int32_t rhs) const {
   return Time(*this) /= rhs;
 }
+double Time::operator/(const Time &rhs) const {
+  return ToSeconds() / rhs.ToSeconds();
+}
 Time &Time::operator%=(int32_t rhs) {
   nsec_ = ToNSec() % rhs;
   const int wraps = nsec_ / kNSecInSec;
diff --git a/aos/common/time.h b/aos/common/time.h
index ea703f7..276cf1c 100644
--- a/aos/common/time.h
+++ b/aos/common/time.h
@@ -160,6 +160,8 @@
   const Time operator-(const Time &rhs) const;
   const Time operator*(int32_t rhs) const;
   const Time operator/(int32_t rhs) const;
+  // TODO(brians) test this
+  double operator/(const Time &rhs) const;
   const Time operator%(int32_t rhs) const;
 
   bool operator==(const Time &rhs) const;
diff --git a/frc971/atom_code/atom_code.gyp b/frc971/atom_code/atom_code.gyp
index 710a5d4..e9cfeff 100644
--- a/frc971/atom_code/atom_code.gyp
+++ b/frc971/atom_code/atom_code.gyp
@@ -28,6 +28,7 @@
         #'camera/camera.gyp:frc971',
         '../../gyro_board/src/libusb-driver/libusb-driver.gyp:get',
         '../input/input.gyp:gyro_board_reader',
+        '../input/input.gyp:gyro_sensor_receiver',
       ],
       'copies': [
         {
diff --git a/frc971/input/gyro_sensor_receiver.cc b/frc971/input/gyro_sensor_receiver.cc
new file mode 100644
index 0000000..aedc9a3
--- /dev/null
+++ b/frc971/input/gyro_sensor_receiver.cc
@@ -0,0 +1,270 @@
+#include <libusb-1.0/libusb.h>
+#include <memory>
+
+#include "aos/common/inttypes.h"
+#include "aos/atom_code/init.h"
+#include "aos/common/logging/logging.h"
+#include "aos/common/time.h"
+#include "aos/common/sensors/sensor_unpacker.h"
+#include "aos/common/sensors/sensor_receiver.h"
+
+#include "frc971/control_loops/drivetrain/drivetrain.q.h"
+#include "frc971/control_loops/wrist/wrist_motor.q.h"
+#include "frc971/control_loops/angle_adjust/angle_adjust_motor.q.h"
+#include "frc971/control_loops/index/index_motor.q.h"
+#include "frc971/control_loops/shooter/shooter_motor.q.h"
+#include "frc971/input/gyro_board_data.h"
+#include "gyro_board/src/libusb-driver/libusb_wrap.h"
+#include "frc971/queues/GyroAngle.q.h"
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+using ::frc971::control_loops::drivetrain;
+using ::frc971::control_loops::wrist;
+using ::frc971::control_loops::angle_adjust;
+using ::frc971::control_loops::shooter;
+using ::frc971::control_loops::index_loop;
+using ::frc971::sensors::gyro;
+
+namespace frc971 {
+namespace {
+
+inline double drivetrain_translate(int32_t in) {
+  return static_cast<double>(in) / (256.0 /*cpr*/ * 4.0 /*quad*/) *
+      (19.0 / 50.0) /*output reduction*/ * (64.0 / 24.0) /*encoder gears*/ *
+      (3.5 /*wheel diameter*/ * 2.54 / 100.0 * M_PI);
+}
+
+inline double wrist_translate(int32_t in) {
+  return static_cast<double>(in) / (256.0 /*cpr*/ * 4.0 /*quad*/) *
+      (14.0 / 50.0 * 20.0 / 84.0) /*gears*/ * (2 * M_PI);
+}
+
+inline double angle_adjust_translate(int32_t in) {
+  static const double kCableDiameter = 0.060;
+  return -static_cast<double>(in) / (256.0 /*cpr*/ * 4.0 /*quad*/) *
+      ((0.75 + kCableDiameter) / (16.61125 + kCableDiameter)) /*pulleys*/ *
+      (2 * M_PI);
+}
+
+inline double shooter_translate(int32_t in) {
+ return static_cast<double>(in) / (32.0 /*cpr*/ * 4.0 /*quad*/) *
+      (15.0 / 34.0) /*gears*/ * (2 * M_PI);
+}
+
+inline double index_translate(int32_t in) {
+  return -static_cast<double>(in) / (128.0 /*cpr*/ * 4.0 /*quad*/) *
+      (1.0) /*gears*/ * (2 * M_PI);
+}
+
+}  // namespace
+
+class GyroSensorUnpacker :
+    public ::aos::sensors::SensorUnpackerInterface<GyroBoardData> {
+ public:
+  GyroSensorUnpacker()
+      : top_rise_count_(0),
+        last_top_rise_count_(0),
+        top_fall_count_(0),
+        last_top_fall_count_(0),
+        bottom_rise_count_(0),
+        last_bottom_rise_count_(0),
+        bottom_fall_delay_count_(0),
+        last_bottom_fall_delay_count_(0),
+        bottom_fall_count_(0),
+        last_bottom_fall_count_(0),
+        wrist_rise_count_(0),
+        last_wrist_rise_count_(0),
+        shooter_angle_rise_count_(0),
+        last_shooter_angle_rise_count_(0) {
+  }
+
+  void UnpackFrom(GyroBoardData *data) {
+    data->NetworkToHost();
+    LOG(DEBUG, "processing a packet\n");
+
+    static ::aos::time::Time last_time = ::aos::time::Time::Now();
+    if ((last_time - ::aos::time::Time::Now()) >
+        ::aos::time::Time::InMS(0.00205)) {
+      LOG(INFO, "missed one\n");
+    }
+
+    gyro.MakeWithBuilder()
+        .angle(data->gyro_angle / 16.0 / 1000.0 / 180.0 * M_PI)
+        .Send();
+
+    UpdateWrappingCounter(data->top_rise_count,
+        &last_top_rise_count_, &top_rise_count_);
+    UpdateWrappingCounter(data->top_fall_count,
+        &last_top_fall_count_, &top_fall_count_);
+    UpdateWrappingCounter(data->bottom_rise_count,
+        &last_bottom_rise_count_, &bottom_rise_count_);
+    UpdateWrappingCounter(data->bottom_fall_delay_count,
+        &last_bottom_fall_delay_count_, &bottom_fall_delay_count_);
+    UpdateWrappingCounter(data->bottom_fall_count,
+        &last_bottom_fall_count_, &bottom_fall_count_);
+    UpdateWrappingCounter(data->wrist_rise_count,
+        &last_wrist_rise_count_, &wrist_rise_count_);
+    UpdateWrappingCounter(data->shooter_angle_rise_count,
+        &last_shooter_angle_rise_count_, &shooter_angle_rise_count_);
+
+    drivetrain.position.MakeWithBuilder()
+        .right_encoder(-drivetrain_translate(data->right_drive))
+        .left_encoder(drivetrain_translate(data->left_drive))
+        .Send();
+
+    wrist.position.MakeWithBuilder()
+        .pos(wrist_translate(data->wrist))
+        .hall_effect(!data->wrist_hall_effect)
+        .calibration(wrist_translate(data->capture_wrist_rise))
+        .Send();
+
+    angle_adjust.position.MakeWithBuilder()
+        .angle(angle_adjust_translate(data->shooter_angle))
+        .bottom_hall_effect(!data->angle_adjust_bottom_hall_effect)
+        .middle_hall_effect(false)
+        .bottom_calibration(angle_adjust_translate(
+                data->capture_shooter_angle_rise))
+        .middle_calibration(angle_adjust_translate(
+                0))
+        .Send();
+
+    shooter.position.MakeWithBuilder()
+        .position(shooter_translate(data->shooter))
+        .Send();
+
+    index_loop.position.MakeWithBuilder()
+        .index_position(index_translate(data->indexer))
+        .top_disc_detect(!data->top_disc)
+        .top_disc_posedge_count(top_rise_count_)
+        .top_disc_posedge_position(index_translate(data->capture_top_rise))
+        .top_disc_negedge_count(top_fall_count_)
+        .top_disc_negedge_position(index_translate(data->capture_top_fall))
+        .bottom_disc_detect(!data->bottom_disc)
+        .bottom_disc_posedge_count(bottom_rise_count_)
+        .bottom_disc_negedge_count(bottom_fall_count_)
+        .bottom_disc_negedge_wait_position(index_translate(
+                data->capture_bottom_fall_delay))
+        .bottom_disc_negedge_wait_count(bottom_fall_delay_count_)
+        .Send();
+  }
+
+ private:
+  void UpdateWrappingCounter(
+      uint8_t current, uint8_t *last, int32_t *counter) {
+    if (*last > current) {
+      *counter += 0x100;
+    }
+    *counter = (*counter & 0xffffff00) | current;
+    *last = current;
+  }
+
+  int32_t top_rise_count_;
+  uint8_t last_top_rise_count_;
+  int32_t top_fall_count_;
+  uint8_t last_top_fall_count_;
+  int32_t bottom_rise_count_;
+  uint8_t last_bottom_rise_count_;
+  int32_t bottom_fall_delay_count_;
+  uint8_t last_bottom_fall_delay_count_;
+  int32_t bottom_fall_count_;
+  uint8_t last_bottom_fall_count_;
+  int32_t wrist_rise_count_;
+  uint8_t last_wrist_rise_count_;
+  int32_t shooter_angle_rise_count_;
+  uint8_t last_shooter_angle_rise_count_;
+};
+
+class GyroSensorReceiver :
+    public ::aos::sensors::SensorReceiver<GyroBoardData> {
+ public:
+  GyroSensorReceiver(
+      ::aos::sensors::SensorUnpackerInterface<GyroBoardData> *unpacker)
+      : ::aos::sensors::SensorReceiver<GyroBoardData>(unpacker),
+        start_time_(0, 0) {
+    static_assert(sizeof(GyroBoardData) <= sizeof(data_),
+                  "the buffer is too small");
+  }
+
+ private:
+  static const unsigned char kEndpoint = 0x81;
+  // in ms
+  // 0 is unlimited
+  static const unsigned int kReadTimeout = 1000;
+
+  // vendor ID
+  static const int32_t kVid = 0x1424;
+  // product ID
+  static const int32_t kPid = 0xd243;
+
+  virtual void DoReceiveData() {
+    // Loop and then return once we get a good one.
+    while (true) {
+      int read_bytes;
+      int r = dev_handle_->interrupt_transfer(
+          kEndpoint, data_, sizeof(data_), &read_bytes, kReadTimeout);
+
+      if (r != 0) {
+        if (r == LIBUSB_ERROR_TIMEOUT) {
+          LOG(ERROR, "read timed out\n");
+          continue;
+        }
+        LOG(FATAL, "libusb gave error %d\n", r);
+      }
+
+      if (read_bytes < static_cast<ssize_t>(sizeof(GyroBoardData))) {
+        LOG(ERROR, "read %d bytes instead of at least %zd\n",
+            read_bytes, sizeof(GyroBoardData));
+        continue;
+      }
+
+      memcpy(&data()->values, data_, sizeof(GyroBoardData));
+      if (data()->count == 0) {
+        start_time_ = ::aos::time::Time::Now();
+        data()->count = 1;
+      } else {
+        ::aos::time::Time delta_time = ::aos::time::Time::Now() - start_time_;
+        data()->count = static_cast<int32_t>(
+            (delta_time / ::aos::sensors::kSensorSendFrequency) + 0.5);
+      }
+      return;
+    }
+  }
+
+  virtual void Reset() {
+    dev_handle_ = ::std::unique_ptr<LibUSBDeviceHandle>(
+        libusb_.FindDeviceWithVIDPID(kVid, kPid));
+    if (!dev_handle_) {
+      LOG(FATAL, "couldn't find device\n");
+    }
+    data()->count = 0;
+  }
+
+  virtual void Synchronized(::aos::time::Time start_time) {
+    LOG(INFO, "offset %f\n", (::aos::time::Time::Now() - start_time).ToSeconds());
+    start_time_ = start_time -
+        ::aos::sensors::kSensorSendFrequency * data()->count;
+  }
+
+  ::std::unique_ptr<LibUSBDeviceHandle> dev_handle_;
+
+  ::aos::time::Time start_time_;
+
+  LibUSB libusb_;
+
+  uint8_t data_[64];
+};
+
+}  // namespace frc971
+
+int main() {
+  ::aos::Init();
+  ::frc971::GyroSensorUnpacker unpacker;
+  ::frc971::GyroSensorReceiver receiver(&unpacker);
+  while (true) {
+    receiver.RunIteration();
+  }
+  ::aos::Cleanup();
+}
diff --git a/frc971/input/input.gyp b/frc971/input/input.gyp
index 447ded3..45f68a2 100644
--- a/frc971/input/input.gyp
+++ b/frc971/input/input.gyp
@@ -49,6 +49,27 @@
       ],
     },
     {
+      'target_name': 'gyro_sensor_receiver',
+      'type': 'executable',
+      'sources': [
+        'gyro_sensor_receiver.cc',
+      ],
+      'dependencies': [
+        '<(DEPTH)/frc971/control_loops/drivetrain/drivetrain.gyp:drivetrain_loop',
+        '<(DEPTH)/frc971/queues/queues.gyp:queues',
+        '<(DEPTH)/frc971/control_loops/angle_adjust/angle_adjust.gyp:angle_adjust_loop',
+        '<(DEPTH)/frc971/control_loops/wrist/wrist.gyp:wrist_loop',
+        '<(DEPTH)/frc971/control_loops/index/index.gyp:index_loop',
+        '<(DEPTH)/frc971/control_loops/shooter/shooter.gyp:shooter_loop',
+        '<(AOS)/atom_code/atom_code.gyp:init',
+        '<(DEPTH)/gyro_board/src/libusb-driver/libusb-driver.gyp:libusb_wrap',
+        '<(EXTERNALS):libusb',
+        '<(AOS)/build/aos.gyp:logging',
+        '<(AOS)/common/common.gyp:time',
+        '<(AOS)/common/sensors/sensors.gyp:sensor_receiver',
+      ],
+    },
+    {
       'target_name': 'gyro_board_reader',
       'type': 'executable',
       'sources': [
@@ -65,8 +86,8 @@
         '<(DEPTH)/gyro_board/src/libusb-driver/libusb-driver.gyp:libusb_wrap',
         '<(EXTERNALS):libusb',
         '<(AOS)/build/aos.gyp:logging',
-        '<(AOS)/common/common.gyp:timing',
         '<(AOS)/common/common.gyp:time',
+        '<(AOS)/common/common.gyp:timing',
       ],
     },
     {
diff --git a/gyro_board/src/libusb-driver/libusb_wrap.cc b/gyro_board/src/libusb-driver/libusb_wrap.cc
index 72fc58e..13a5e31 100644
--- a/gyro_board/src/libusb-driver/libusb_wrap.cc
+++ b/gyro_board/src/libusb-driver/libusb_wrap.cc
@@ -81,8 +81,7 @@
     libusb_device_handle *dev_handle) : dev_handle_(dev_handle) { }
 
 LibUSBDeviceHandle::~LibUSBDeviceHandle() {
-  int r;
-  r = libusb_release_interface(dev_handle_, 0);
+  int r = libusb_release_interface(dev_handle_, 0);
   if (r != 0) {
     LOG(FATAL, "Cannot Release Interface\n");
   }