diff --git a/Documentation/README.html b/Documentation/README.html
index aecabdc7aef..2a74c3e5a98 100644
--- a/Documentation/README.html
+++ b/Documentation/README.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX README Files</i></font></big></h1>
-      <p>Last Updated: May 29, 2018</p>
+      <p>Last Updated: May 30, 2018</p>
     </td>
   </tr>
 </table>
@@ -390,6 +390,8 @@ nuttx/
  |   |- libc/
  |   |   |- <a href="https://bitbucket.org/nuttx/nuttx/src/master/libs/libc/zoneinfo/README.txt" target="_blank">zoneinfo/README.txt</a>
  |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/libs/libc/README.txt" target="_blank"><b><i>README.txt</i></b></a>
+ |   |- libdsp/
+ |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/libs/libdsp/README.txt" target="_blank"><b><i>README.txt</i></b></a>
  |   |- libnx/
  |   |   |- <a href="https://bitbucket.org/nuttx/nuttx/src/master/libs/libnx/nxfonts/README.txt" target="_blank">libnx/README.txt</a>
  |   |   `- <a href="https://bitbucket.org/nuttx/nuttx/src/master/libs/libnx/README.txt" target="_blank"><b><i>README.txt</i></b></a>
diff --git a/README.txt b/README.txt
index 5aca4d83b04..49ceb3fc363 100644
--- a/README.txt
+++ b/README.txt
@@ -1981,6 +1981,8 @@ nuttx/
  |   |   |- zoneinfo
  |   |   |   `- README.txt
  |   |   `- README.txt
+ |   |- libdsp/
+ |   |   `- README.txt
  |   |- libnx/
  |   |   |- nxfongs
  |   |   |   `- README.txt
diff --git a/libs/libdsp/lib_observer.c b/libs/libdsp/lib_observer.c
index 0097b3bace9..44d671dd95b 100644
--- a/libs/libdsp/lib_observer.c
+++ b/libs/libdsp/lib_observer.c
@@ -54,7 +54,6 @@
  * Public Functions
  ****************************************************************************/
 
-
 /****************************************************************************
  * Name: motor_observer_init
  *
@@ -317,7 +316,7 @@ void motor_observer_smo(FAR struct motor_observer_s *observer, FAR ab_frame_t *i
 
 #if 1
   /* Some assertions
-   * TODO: simplyfy
+   * TODO: simplify
    */
 
   if (angle != angle) angle = 0.0;
diff --git a/libs/libdsp/lib_pid.c b/libs/libdsp/lib_pid.c
index 0f937559d3e..466d2ce99f4 100644
--- a/libs/libdsp/lib_pid.c
+++ b/libs/libdsp/lib_pid.c
@@ -250,7 +250,7 @@ float pid_controller(FAR pid_controller_t *pid, float err)
 
   pid->part[2] = pid->KD * (err - pid->err_prev);
 
-  /* Add diverative part to the PI part */
+  /* Add derivative part to the PI part */
 
   pid->out +=  pid->part[2];