diff --git a/bbb_cape/src/bbb/bbb.gyp b/bbb_cape/src/bbb/bbb.gyp
index c954482..1722bce 100644
--- a/bbb_cape/src/bbb/bbb.gyp
+++ b/bbb_cape/src/bbb/bbb.gyp
@@ -3,6 +3,11 @@
     'include_dirs': [
       '..',
     ],
+    'direct_dependent_settings': {
+      'include_dirs': [
+        '..',
+      ],
+    },
   },
   'targets': [
     {
@@ -70,6 +75,17 @@
       ],
     },
     {
+      'target_name': 'sensor_generation',
+      'type': 'static_library',
+      'sources': [
+        'sensor_generation.q',
+      ],
+      'variables': {
+        'header_path': 'bbb',
+      },
+      'includes': ['../../../aos/build/queues.gypi'],
+    },
+    {
       'target_name': 'packet_finder',
       'type': 'static_library',
       'sources': [
@@ -126,5 +142,25 @@
         '<(AOS)/build/aos.gyp:logging',
       ],
     },
+    {
+      'target_name': 'sensor_reader',
+      'type': 'static_library',
+      'sources': [
+        'sensor_reader.cc',
+      ],
+      'dependencies': [
+        'uart_reader',
+        'packet_finder',
+        'data_struct',
+        '<(AOS)/common/common.gyp:time',
+        'sensor_generation',
+      ],
+      'export_dependent_settings': [
+        'uart_reader',
+        'packet_finder',
+        'data_struct',
+        '<(AOS)/common/common.gyp:time',
+      ],
+    },
   ],
 }
diff --git a/bbb_cape/src/bbb/byte_reader.h b/bbb_cape/src/bbb/byte_reader.h
index 7818407..16e364c 100644
--- a/bbb_cape/src/bbb/byte_reader.h
+++ b/bbb_cape/src/bbb/byte_reader.h
@@ -17,7 +17,7 @@
   // Returns the number of bytes read, -1 if there is an error in errno, or -2
   // if reading takes longer than timeout.
   virtual ssize_t ReadBytes(AlignedChar *dest, size_t max_bytes,
-                            const ::aos::time::Time &timeout) = 0;
+                            const ::aos::time::Time &timeout_time) = 0;
 };
 
 }  // namespace bbb
diff --git a/bbb_cape/src/bbb/packet_finder.cc b/bbb_cape/src/bbb/packet_finder.cc
index 447d3a8..713ea69 100644
--- a/bbb_cape/src/bbb/packet_finder.cc
+++ b/bbb_cape/src/bbb/packet_finder.cc
@@ -32,9 +32,8 @@
   int zeros_found = 0;
   while (true) {
     size_t already_read = ::std::max(0, packet_bytes_);
-    ssize_t new_bytes =
-        reader_->ReadBytes(buf_ + already_read, packet_size_ - already_read,
-                           timeout_time - ::Time::Now());
+    ssize_t new_bytes = reader_->ReadBytes(
+        buf_ + already_read, packet_size_ - already_read, timeout_time);
     if (new_bytes < 0) {
       if (new_bytes == -1) {
         LOG(ERROR, "ReadBytes(%p, %zd) failed with %d: %s\n",
@@ -50,8 +49,8 @@
 
     if (!irq_priority_increased_) {
       // TODO(brians): Do this cleanly.
-      int chrt_result = system(
-          "bash -c 'chrt -r -p 55 $(top -n1 | fgrep irq/89 | cut -d\" \" -f2)'");
+      int chrt_result = system("bash -c 'chrt -r -p 55"
+                               " $(top -n1 | fgrep irq/89 | cut -d\" \" -f2)'");
       if (chrt_result == -1) {
         LOG(FATAL, "system(chrt -r -p 55 the_irq) failed\n");
       } else if (!WIFEXITED(chrt_result) || WEXITSTATUS(chrt_result) != 0) {
diff --git a/bbb_cape/src/bbb/packet_finder.h b/bbb_cape/src/bbb/packet_finder.h
index b86c0c9..9b74583 100644
--- a/bbb_cape/src/bbb/packet_finder.h
+++ b/bbb_cape/src/bbb/packet_finder.h
@@ -6,6 +6,7 @@
 
 #include "aos/common/logging/logging.h"
 #include "aos/common/time.h"
+#include "aos/common/macros.h"
 
 #include "bbb/byte_reader.h"
 
@@ -61,6 +62,8 @@
 
   // Whether we've increased the priority of the IRQ yet.
   bool irq_priority_increased_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(PacketFinder);
 };
 
 }  // namespace bbb
diff --git a/bbb_cape/src/bbb/sensor_generation.q b/bbb_cape/src/bbb/sensor_generation.q
new file mode 100644
index 0000000..a121999
--- /dev/null
+++ b/bbb_cape/src/bbb/sensor_generation.q
@@ -0,0 +1,14 @@
+package bbb;
+
+// Each different set of values here represents a different set of sensor
+// values (ie different encoder zeros etc).
+message SensorGeneration {
+	// The PID of the process reading sensor values.
+	int32_t reader_pid;
+	// A count of how many times a sensor reading process sees the cape reset.
+	uint32_t cape_resets;
+};
+
+// A new message is placed on here by the process that reads sensor values each
+// time it starts up or detects the cape resetting.
+queue SensorGeneration sensor_generation;
diff --git a/bbb_cape/src/bbb/sensor_reader.cc b/bbb_cape/src/bbb/sensor_reader.cc
new file mode 100644
index 0000000..2c36ae3
--- /dev/null
+++ b/bbb_cape/src/bbb/sensor_reader.cc
@@ -0,0 +1,61 @@
+#include "bbb/sensor_reader.h"
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include "bbb/sensor_generation.q.h"
+
+namespace bbb {
+
+SensorReader::SensorReader(const ::std::string &/*cape_code*/)
+    : reader_(750000), packet_finder_(&reader_, DATA_STRUCT_SEND_SIZE - 4) {
+  static_assert(sizeof(SensorGeneration::reader_pid) >= sizeof(pid_t),
+                "pid_t is really big");
+  ResetHappened();
+}
+
+const DataStruct *SensorReader::ReadPacket() {
+  static constexpr ::aos::time::Time kTimeout =
+      ::aos::time::Time::InSeconds(0.5);
+
+  while (true) {
+    ::aos::time::Time next_timeout = last_received_time_ + kTimeout;
+    if (next_timeout <= ::aos::time::Time::Now()) {
+      LOG(WARNING, "too long since good packet received\n");
+      Reset(false);
+    }
+    if (packet_finder_.ReadPacket(next_timeout)) {
+      last_received_time_ = ::aos::time::Time::Now();
+      const DataStruct *data = packet_finder_.get_packet<DataStruct>();
+      // TODO(brians): Check the flash checksum and reflash it if necessary.
+      if (data->timestamp < last_cape_timestamp_) {
+        LOG(WARNING, "cape timestamp decreased: %" PRIu64 " to %" PRIu64 "\n",
+            last_cape_timestamp_, data->timestamp);
+        ResetHappened();
+      }
+      last_cape_timestamp_ = data->timestamp;
+      return data;
+    }
+    LOG(WARNING, "receiving packet failed\n");
+  }
+}
+
+::aos::time::Time SensorReader::GetCapeTimestamp() {
+  return ::aos::time::Time::InUS(last_cape_timestamp_ * 10);
+}
+
+void SensorReader::Reset(bool reflash) {
+  LOG(INFO, "Reset(%s)\n", reflash ? "true" : "false");
+  // TODO(brians): Actually reset it and maybe reflash it.
+  ResetHappened();
+}
+
+void SensorReader::ResetHappened() {
+  sensor_generation.MakeWithBuilder().reader_pid(getpid())
+      .cape_resets(cape_resets_++).Send();
+  last_received_time_ = ::aos::time::Time::Now();
+  last_cape_timestamp_ = 0;
+}
+
+}  // namespace bbb
diff --git a/bbb_cape/src/bbb/sensor_reader.h b/bbb_cape/src/bbb/sensor_reader.h
new file mode 100644
index 0000000..16b2496
--- /dev/null
+++ b/bbb_cape/src/bbb/sensor_reader.h
@@ -0,0 +1,50 @@
+#ifndef BBB_CAPE_SRC_BBB_SENSOR_READER_H_
+#define BBB_CAPE_SRC_BBB_SENSOR_READER_H_
+
+#include <string>
+
+#include "aos/common/time.h"
+
+#include "bbb/uart_reader.h"
+#include "bbb/packet_finder.h"
+#include "bbb/data_struct.h"
+
+namespace bbb {
+
+// A class that handles reading sensor values from the BBB cape.
+// Automatically handles the gyro data and exposes the other data for other code
+// to deal with.
+class SensorReader {
+ public:
+  // The relative priority that tasks doing this should get run at (ie what to
+  // pass to ::aos::Init(int)).
+  static const int kRelativePriority = 5;
+
+  // cape_code is the name of the code that should be deployed to the cape if
+  // it's not already there.
+  SensorReader(const ::std::string &cape_code);
+
+  // Reads in 1 data packet, handles the gyro data in it, and returns a pointer
+  // to it.
+  const DataStruct *ReadPacket();
+
+  // Returns the timestamp the cape sent with the most recently read packet.
+  ::aos::time::Time GetCapeTimestamp();
+
+ private:
+  // Resets the cape.
+  void Reset(bool reflash);
+  // Called after a reset happens.
+  void ResetHappened();
+
+  UartReader reader_;
+  PacketFinder packet_finder_;
+
+  int cape_resets_ = 0;
+  ::aos::time::Time last_received_time_ = ::aos::time::Time::InSeconds(0);
+  uint64_t last_cape_timestamp_;
+};
+
+}  // namespace bbb
+
+#endif  // BBB_CAPE_SRC_BBB_SENSOR_READER_H_
diff --git a/bbb_cape/src/bbb/uart_reader.cc b/bbb_cape/src/bbb/uart_reader.cc
index f4ebaca..cebe127 100644
--- a/bbb_cape/src/bbb/uart_reader.cc
+++ b/bbb_cape/src/bbb/uart_reader.cc
@@ -54,8 +54,10 @@
 }
 
 ssize_t UartReader::ReadBytes(AlignedChar *dest, size_t max_bytes,
-                              const ::aos::time::Time &timeout) {
+                              const ::aos::time::Time &timeout_time) {
   do {
+    ::aos::time::Time timeout = timeout_time - ::aos::time::Time::Now();
+    if (timeout < ::aos::time::Time(0, 0)) return -2;
     struct timeval timeout_timeval = timeout.ToTimeval();
     switch (select(fd_ + 1, &fd_set_, NULL, NULL, &timeout_timeval)) {
       case 0:
diff --git a/bbb_cape/src/bbb/uart_reader.h b/bbb_cape/src/bbb/uart_reader.h
index 2d038ea..c441167 100644
--- a/bbb_cape/src/bbb/uart_reader.h
+++ b/bbb_cape/src/bbb/uart_reader.h
@@ -6,6 +6,7 @@
 #include <sys/select.h>
 
 #include "aos/common/time.h"
+#include "aos/common/macros.h"
 
 #include "bbb/byte_reader.h"
 
@@ -17,12 +18,14 @@
   virtual ~UartReader();
 
   virtual ssize_t ReadBytes(AlignedChar *dest, size_t max_bytes,
-                            const ::aos::time::Time &timeout) override;
+                            const ::aos::time::Time &timeout_time) override;
 
  private:
   const int fd_;
   // Gets initialized to only contain fd_.
   fd_set fd_set_;
+
+  DISALLOW_COPY_AND_ASSIGN(UartReader);
 };
 
 }  // namespace bbb