diff --git a/klippy/chelper.py b/klippy/chelper.py
index cca91b43..7fb8fd98 100644
--- a/klippy/chelper.py
+++ b/klippy/chelper.py
@@ -7,9 +7,9 @@ import os, logging
 import cffi
 
 COMPILE_CMD = "gcc -Wall -g -O -shared -fPIC -o %s %s"
-SOURCE_FILES = ['stepcompress.c', 'serialqueue.c']
+SOURCE_FILES = ['stepcompress.c', 'serialqueue.c', 'pyhelper.c']
 DEST_LIB = "c_helper.so"
-OTHER_FILES = ['list.h', 'serialqueue.h']
+OTHER_FILES = ['list.h', 'serialqueue.h', 'pyhelper.h']
 
 defs_stepcompress = """
     struct stepcompress *stepcompress_alloc(uint32_t max_error
diff --git a/klippy/pyhelper.c b/klippy/pyhelper.c
new file mode 100644
index 00000000..3de9c2e8
--- /dev/null
+++ b/klippy/pyhelper.c
@@ -0,0 +1,62 @@
+// Helper functions for C / Python interface
+//
+// Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include <errno.h> // errno
+#include <stdint.h> // uint8_t
+#include <stdio.h> // fprintf
+#include <string.h> // strerror
+#include <sys/time.h> // gettimeofday
+#include <time.h> // struct timespec
+#include "pyhelper.h" // get_time
+
+// Return the current system time as a double
+double
+get_time(void)
+{
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return (double)tv.tv_sec + (double)tv.tv_usec / 1000000.;
+}
+
+// Fill a 'struct timespec' with a system time stored in a double
+struct timespec
+fill_time(double time)
+{
+    time_t t = time;
+    return (struct timespec) {t, (time - t)*1000000000. };
+}
+
+// Report 'errno' in a message written to stderr
+void
+report_errno(char *where, int rc)
+{
+    int e = errno;
+    fprintf(stderr, "Got error %d in %s: (%d)%s\n", rc, where, e, strerror(e));
+}
+
+// Return a hex character for a given number
+#define GETHEX(x) ((x) < 10 ? '0' + (x) : 'e' + (x) - 10)
+
+// Translate a binary string into an ASCII string with escape sequences
+char *
+dump_string(char *outbuf, int outbuf_size, char *inbuf, int inbuf_size)
+{
+    char *outend = &outbuf[outbuf_size-5], *o = outbuf;
+    uint8_t *inend = (void*)&inbuf[inbuf_size], *p = (void*)inbuf;
+    while (p < inend && o < outend) {
+        uint8_t c = *p++;
+        if (c > 31 && c < 127 && c != '\\') {
+            *o++ = c;
+            continue;
+        }
+        *o++ = '\\';
+        *o++ = 'x';
+        *o++ = GETHEX(c >> 4);
+        *o++ = GETHEX(c & 0x0f);
+    }
+    *o = '\0';
+    return outbuf;
+}
diff --git a/klippy/pyhelper.h b/klippy/pyhelper.h
new file mode 100644
index 00000000..ccf16ab8
--- /dev/null
+++ b/klippy/pyhelper.h
@@ -0,0 +1,9 @@
+#ifndef PYHELPER_H
+#define PYHELPER_H
+
+double get_time(void);
+struct timespec fill_time(double time);
+void report_errno(char *where, int rc);
+char *dump_string(char *outbuf, int outbuf_size, char *inbuf, int inbuf_size);
+
+#endif // pyhelper.h
diff --git a/klippy/serialqueue.c b/klippy/serialqueue.c
index 0700ecc3..6274e277 100644
--- a/klippy/serialqueue.c
+++ b/klippy/serialqueue.c
@@ -12,7 +12,6 @@
 // clock times, prioritizes commands, and handles retransmissions.  A
 // background thread is launched to do this work and minimize latency.
 
-#include <errno.h> // errno
 #include <math.h> // ceil
 #include <poll.h> // poll
 #include <pthread.h> // pthread_mutex_lock
@@ -21,70 +20,13 @@
 #include <stdio.h> // snprintf
 #include <stdlib.h> // malloc
 #include <string.h> // memset
-#include <sys/time.h> // gettimeofday
-#include <time.h> // struct timespec
 #include <termios.h> // tcflush
 #include <unistd.h> // pipe
 #include "list.h" // list_add_tail
+#include "pyhelper.h" // get_time
 #include "serialqueue.h" // struct queue_message
 
 
-/****************************************************************
- * Helper functions
- ****************************************************************/
-
-// Return the current system time as a double
-static double
-get_time(void)
-{
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return (double)tv.tv_sec + (double)tv.tv_usec / 1000000.;
-}
-
-#if 0
-// Fill a 'struct timespec' with a system time stored in a double
-struct timespec
-fill_time(double time)
-{
-    time_t t = time;
-    return (struct timespec) {t, (time - t)*1000000000. };
-}
-#endif
-
-// Report 'errno' in a message written to stderr
-void
-report_errno(char *where, int rc)
-{
-    int e = errno;
-    fprintf(stderr, "Got error %d in %s: (%d)%s\n", rc, where, e, strerror(e));
-}
-
-// Return a hex character for a given number
-#define GETHEX(x) ((x) < 10 ? '0' + (x) : 'e' + (x) - 10)
-
-// Translate a binary string into an ASCII string with escape sequences
-char *
-dump_string(char *outbuf, int outbuf_size, uint8_t *inbuf, int inbuf_size)
-{
-    char *outend = &outbuf[outbuf_size-5], *o = outbuf;
-    uint8_t *inend = &inbuf[inbuf_size], *p = inbuf;
-    while (p < inend && o < outend) {
-        uint8_t c = *p++;
-        if (c > 31 && c < 127 && c != '\\') {
-            *o++ = c;
-            continue;
-        }
-        *o++ = '\\';
-        *o++ = 'x';
-        *o++ = GETHEX(c >> 4);
-        *o++ = GETHEX(c & 0x0f);
-    }
-    *o = '\0';
-    return outbuf;
-}
-
-
 /****************************************************************
  * Poll reactor
  ****************************************************************/