Clean up a few after-merge idiosyncrasies.

- Get the bot3 input code up to date. (Again.)
- Get rid of old gyro_reader.cc file, which somehow survived.
diff --git a/bot3/input/gyro_sensor_receiver.cc b/bot3/input/gyro_sensor_receiver.cc
index 6553e3a..f53f15b 100644
--- a/bot3/input/gyro_sensor_receiver.cc
+++ b/bot3/input/gyro_sensor_receiver.cc
@@ -1,17 +1,10 @@
-#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 "aos/common/util/wrapping_counter.h"
 
 #include "bot3/control_loops/drivetrain/drivetrain.q.h"
-#include "frc971/input/gyro_board_data.h"
-#include "gyro_board/src/libusb-driver/libusb_wrap.h"
 #include "frc971/queues/GyroAngle.q.h"
+#include "frc971/input/usb_receiver.h"
 
 #ifndef M_PI
 #define M_PI 3.14159265358979323846
@@ -19,7 +12,8 @@
 
 using ::bot3::control_loops::drivetrain;
 using ::frc971::sensors::gyro;
-using ::frc971::GyroBoardData;
+using ::aos::util::WrappingCounter;
+using ::frc971::USBReceiver;
 
 namespace bot3 {
 namespace {
@@ -54,203 +48,40 @@
 
 }  // 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");
+class GyroSensorReceiver : public USBReceiver {
+  virtual void ProcessData() override {
+    if (data()->robot_id != 0) {
+      LOG(ERROR, "gyro board sent data for robot id %hhd!"
+          " dip switches are %x\n",
+          data()->robot_id, data()->base_status & 0xF);
+      return;
+    } else {
+      LOG(DEBUG, "processing a packet dip switches %x\n",
+          data()->base_status & 0xF);
     }
 
     gyro.MakeWithBuilder()
-        .angle(data->gyro_angle / 16.0 / 1000.0 / 180.0 * M_PI)
+        .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))
+        .right_encoder(drivetrain_translate(data()->main.right_drive))
+        .left_encoder(-drivetrain_translate(data()->main.left_drive))
         .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) <= kDataLength,
-                  "the buffer will be 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;
-
-  // How big of a buffer to give the function.
-  static const size_t kDataLength = 64;
-
-  virtual void DoReceiveData() {
-    // Loop and then return once we get a good one.
-    while (true) {
-      completed_transfer_ = NULL;
-      while (completed_transfer_ == NULL) {
-        libusb_.HandleEvents();
-      }
-      LOG(DEBUG, "processing transfer %p\n", completed_transfer_);
-
-      if (completed_transfer_->read_bytes() <
-          static_cast<ssize_t>(sizeof(GyroBoardData))) {
-        LOG(ERROR, "read %d bytes instead of at least %zd\n",
-            completed_transfer_->read_bytes(), sizeof(GyroBoardData));
-        continue;
-      }
-
-      memcpy(&data()->values, completed_transfer_->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() {
-    transfer1_.reset();
-    transfer2_.reset();
-    dev_handle_ = ::std::unique_ptr<LibUSBDeviceHandle>(
-        libusb_.FindDeviceWithVIDPID(kVid, kPid));
-    if (!dev_handle_) {
-      LOG(ERROR, "couldn't find device. exiting\n");
-      exit(1);
-    }
-    transfer1_ = ::std::unique_ptr<libusb::Transfer>(
-        new libusb::Transfer(kDataLength, StaticTransferCallback, this));
-    transfer2_ = ::std::unique_ptr<libusb::Transfer>(
-        new libusb::Transfer(kDataLength, StaticTransferCallback, this));
-    transfer1_->FillInterrupt(dev_handle_.get(), kEndpoint, kReadTimeout);
-    transfer2_->FillInterrupt(dev_handle_.get(), kEndpoint, kReadTimeout);
-    transfer1_->Submit();
-    transfer2_->Submit();
-
-    data()->count = 0;
-  }
-
-  static void StaticTransferCallback(libusb::Transfer *transfer, void *self) {
-    static_cast<GyroSensorReceiver *>(self)->TransferCallback(transfer);
-  }
-  void TransferCallback(libusb::Transfer *transfer) {
-    if (transfer->status() == LIBUSB_TRANSFER_COMPLETED) {
-      LOG(DEBUG, "transfer %p completed\n", transfer);
-      completed_transfer_ = transfer;
-    } else if (transfer->status() == LIBUSB_TRANSFER_TIMED_OUT) {
-      LOG(WARNING, "transfer %p timed out\n", transfer);
-    } else if (transfer->status() == LIBUSB_TRANSFER_CANCELLED) {
-      LOG(DEBUG, "transfer %p cancelled\n", transfer);
-    } else {
-      LOG(FATAL, "transfer %p has status %d\n", transfer, transfer->status());
-    }
-    transfer->Submit();
-  }
-
-  virtual void Synchronized(::aos::time::Time start_time) {
-    // Subtract off how many packets it read while synchronizing from the time.
-    start_time_ = start_time -
-        ::aos::sensors::kSensorSendFrequency * data()->count;
-  }
-
-  ::std::unique_ptr<LibUSBDeviceHandle> dev_handle_;
-  ::std::unique_ptr<libusb::Transfer> transfer1_, transfer2_;
-  // Temporary variable for holding a completed transfer to communicate that
-  // information from the callback to the code that wants it.
-  libusb::Transfer *completed_transfer_;
-
-  ::aos::time::Time start_time_;
-
-  LibUSB libusb_;
+  WrappingCounter top_rise_;
+  WrappingCounter top_fall_;
+  WrappingCounter bottom_rise_;
+  WrappingCounter bottom_fall_delay_;
+  WrappingCounter bottom_fall_; 
 };
 
 }  // namespace bot3
 
 int main() {
   ::aos::Init();
-  ::bot3::GyroSensorUnpacker unpacker;
-  ::bot3::GyroSensorReceiver receiver(&unpacker);
+  ::bot3::GyroSensorReceiver receiver;
   while (true) {
     receiver.RunIteration();
   }