diff --git a/source/common.c b/source/common.c
index e36b7ec..4bd2463 100644
--- a/source/common.c
+++ b/source/common.c
@@ -131,7 +131,7 @@ pins_t pins_info[] = {
   { "CSID7",     "U14_38", 139, BASE_METHOD_AS_IS, -1, -1},
   { "GND",       "U14_39", 0, BASE_METHOD_AS_IS, -1, -1},
   { "GND",       "U14_40", 0, BASE_METHOD_AS_IS, -1, -1},
-    { NULL, NULL, 0 }
+  { NULL,        NULL,     0, 0,                 -1, -1}
 };
 
 
@@ -178,10 +178,10 @@ int get_xio_base(void)
             /* Found the expander, get the contents of base */
             snprintf(base_file, sizeof(base_file), "%s/%s/base", GPIO_PATH, ent->d_name); BUF2SMALL(base_file);
             base_fp = fopen(base_file, "r");  ASSRT(base_fp != NULL);
-            s = fgets(input_line, sizeof(input_line), base_fp);
-              ASSRT(s == input_line && strlen(input_line) < sizeof(input_line)-1);
+            s = fgets(input_line, sizeof(input_line), base_fp); BUF2SMALL(input_line); ASSRT(s);
             fclose(base_fp);
-            xio_base_address = atoi(input_line);  /* remember the result */
+            /* Remember the value in the static local. */
+            xio_base_address = atoi(input_line);  ASSRT(xio_base_address > 0);
             num_get_xio_base++;  /* for self-test purposes */
           }
         }  /* if label file is open */
@@ -377,7 +377,7 @@ int build_path(const char *partial_path, const char *prefix, char *full_path, si
     dp = opendir (partial_path);
     if (dp != NULL) {
         while ((ep = readdir (dp))) {
-            // Enforce that the prefix must be the first part of the file
+            // Enforce that the prefix must be the first part of the file name
             char* found_string = strstr(ep->d_name, prefix);
 
             if (found_string != NULL && (ep->d_name - found_string) == 0) {
@@ -419,3 +419,75 @@ int get_spi_bus_path_number(unsigned int spi)
     return -1;
   }
 }
+
+
+struct dyn_int_array {
+  int num_elements;
+  int *array;
+};
+
+void *dyn_int_array_create(int initial_num_elements, int initial_val)
+{
+  struct dyn_int_array *new_array = (struct dyn_int_array *)malloc(sizeof(struct dyn_int_array));
+  ASSRT(new_array != NULL);
+  new_array->num_elements = initial_num_elements;
+  new_array->array = (int *)malloc(initial_num_elements * sizeof(int));
+  ASSRT(new_array->array != NULL);
+  int i;
+  for (i = 0; i < initial_num_elements; i++)
+    new_array->array[i] = initial_val;
+
+  return (void *)new_array;
+}  /* dyn_int_array_create */
+
+
+void dyn_int_array_set(void **in_array, int i, int val, int initial_val)
+{
+  struct dyn_int_array *array = (struct dyn_int_array *)(*in_array);
+  if (array == NULL)
+    array = dyn_int_array_create(i * 3 / 2, initial_val);
+
+  if (i >= array->num_elements) {
+    int new_num_elements = i * 3 / 2;  /* half-again larger than current request */
+    array->array = realloc(array->array, new_num_elements * sizeof(int));
+    ASSRT(array->array != NULL);
+    // Zero out the newly allocated elements.
+    while (array->num_elements < new_num_elements) {
+      array->array[array->num_elements] = initial_val;
+      array->num_elements ++;
+    }
+  }
+
+  array->array[i] = val;
+  *in_array = (void *)array;
+}  /* dyn_int_array_set */
+
+
+int dyn_int_array_get(void **in_array, int i, int initial_val)
+{
+  struct dyn_int_array *array = (struct dyn_int_array *)(*in_array);
+  if (array == NULL)
+    array = dyn_int_array_create(i * 3 / 2, initial_val);
+
+  if (i >= array->num_elements) {
+    int new_num_elements = i * 3 / 2;  /* half-again larger than current request */
+    array->array = realloc(array->array, new_num_elements * sizeof(int));
+    ASSRT(array->array != NULL);
+    // Zero out the newly allocated elements.
+    while (array->num_elements < new_num_elements) {
+      array->array[array->num_elements] = initial_val;
+      array->num_elements ++;
+    }
+  }
+
+  return array->array[i];
+  *in_array = (void *)array;
+}  /* dyn_int_array_get */
+
+
+void dyn_int_array_delete(void **in_array)
+{
+  struct dyn_int_array *array = (struct dyn_int_array *)(*in_array);
+  free(array->array);
+  free(array);
+}  /* dyn_int_array_delete */
diff --git a/source/common.h b/source/common.h
index 54ae1e3..7fafeb3 100644
--- a/source/common.h
+++ b/source/common.h
@@ -41,7 +41,7 @@ SOFTWARE.
 // See http://blog.geeky-boy.com/2016/06/of-compiler-warnings-and-asserts-in.html
 #define ASSRT(cond_expr) do { \
   if (!(cond_expr)) { \
-    fprintf(stderr, "ASSRT failed at %s:%d (%s)", __FILE__, __LINE__, #cond_expr); \
+    fprintf(stderr, "ASSRT failed at %s:%d (%s)\n", __FILE__, __LINE__, #cond_expr); \
     fflush(stderr); \
     abort(); \
 } } while (0)
@@ -75,6 +75,7 @@ int setup_error;
 int module_setup;
 
 int get_xio_base(void);
+int gpio_number(pins_t *pin);
 int lookup_gpio_by_key(const char *key);
 int lookup_gpio_by_name(const char *name);
 int lookup_ain_by_key(const char *key);
@@ -89,3 +90,6 @@ int get_pwm_key(const char *input, char *key);
 int get_adc_ain(const char *key, unsigned int *ain);
 int build_path(const char *partial_path, const char *prefix, char *full_path, size_t full_path_len);
 int get_spi_bus_path_number(unsigned int spi);
+void dyn_int_array_set(void **in_array, int i, int val, int initial_val);
+int dyn_int_array_get(void **in_array, int i, int initial_val);
+void dyn_int_array_delete(void **in_array);
diff --git a/source/event_gpio.c b/source/event_gpio.c
index c5576f7..6f28f81 100644
--- a/source/event_gpio.c
+++ b/source/event_gpio.c
@@ -77,7 +77,7 @@ struct gpio_exp
 struct gpio_exp *exported_gpios = NULL;
 
 pthread_t threads;
-int event_occurred[430] = { 0 };
+void *event_occurred = NULL;
 int thread_running = 0;
 int epfd = -1;
 
@@ -92,8 +92,12 @@ int gpio_export(unsigned int gpio)
         return -1;
     }
     len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio); BUF2SMALL(str_gpio);
-    ssize_t s = write(fd, str_gpio, len);  ASSRT(s == len);
+    ssize_t s = write(fd, str_gpio, len);
     close(fd);
+    if (s != len)
+    {
+        return -1;
+    }
 
     // add to list
     new_gpio = malloc(sizeof(struct gpio_exp));
@@ -183,8 +187,9 @@ int open_value_file(unsigned int gpio)
     // create file descriptor of value file
     snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/value", gpio); BUF2SMALL(filename);
 
-    if ((fd = open(filename, O_RDONLY | O_NONBLOCK)) < 0)
-    return -1;
+    if ((fd = open(filename, O_RDONLY | O_NONBLOCK)) < 0) {
+        return -1;
+    }
     add_fd_list(gpio, fd);
     return fd;
 }
@@ -240,7 +245,6 @@ int gpio_set_direction(unsigned int gpio, unsigned int in_flag)
         } else {
             strncpy(direction, "in", ARRAY_SIZE(direction) - 1);
         }
-
         ssize_t s = write(fd, direction, strlen(direction));  ASSRT(s == strlen(direction));
         close(fd);
         return 0;
@@ -285,8 +289,11 @@ int gpio_set_value(unsigned int gpio, unsigned int value)
         strncpy(vstr, "0", ARRAY_SIZE(vstr) - 1);
     }
 
-    ssize_t s = write(fd, vstr, strlen(vstr));  ASSRT(s == strlen(vstr));
+    ssize_t s = write(fd, vstr, strlen(vstr));
     close(fd);
+
+    if (s != strlen(vstr))
+        return -2;
     return 0;
 }
 
@@ -454,11 +461,12 @@ void *poll_thread(void *threadarg)
                 thread_running = 0;
                 pthread_exit(NULL);
             }
+            // The return value represents the ending level after the edge.
             gpio = gpio_lookup(events.data.fd);
             if (gpio_initial(gpio)) {     // ignore first epoll trigger
                 set_initial_false(gpio);
             } else {
-                event_occurred[gpio] = 1;
+                dyn_int_array_set(&event_occurred, gpio, 1, 0);
                 run_callbacks(gpio);
             }
         }
@@ -512,6 +520,7 @@ int gpio_event_remove(unsigned int gpio)
     return 0;
 }
 
+// add_edge_detect assumes the caller has ensured the GPIO is already exported.
 int add_edge_detect(unsigned int gpio, unsigned int edge)
 // return values:
 // 0 - Success
@@ -528,31 +537,34 @@ int add_edge_detect(unsigned int gpio, unsigned int edge)
         return 1;
 
     // export /sys/class/gpio interface
-    gpio_export(gpio);
     gpio_set_direction(gpio, 0); // 0=input
     gpio_set_edge(gpio, edge);
 
     if (!fd)
     {
-        if ((fd = open_value_file(gpio)) == -1)
+        if ((fd = open_value_file(gpio)) == -1) {
             return 2;
+        }
     }
 
     // create epfd if not already open
-    if ((epfd == -1) && ((epfd = epoll_create(1)) == -1))
+    if ((epfd == -1) && ((epfd = epoll_create(1)) == -1)) {
         return 2;
+    }
 
     // add to epoll fd
     ev.events = EPOLLIN | EPOLLET | EPOLLPRI;
     ev.data.fd = fd;
-    if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev) == -1)
+    if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev) == -1) {
         return 2;
+    }
 
     // start poll thread if it is not already running
     if (!thread_running)
     {
-        if (pthread_create(&threads, NULL, poll_thread, (void *)t) != 0)
+        if (pthread_create(&threads, NULL, poll_thread, (void *)t) != 0) {
             return 2;
+        }
     }
 
     return 0;
@@ -576,13 +588,13 @@ void remove_edge_detect(unsigned int gpio)
     gpio_event_remove(gpio);
 
     // clear detected flag
-    event_occurred[gpio] = 0;
+    dyn_int_array_set(&event_occurred, gpio, 0, 0);
 }
 
 int event_detected(unsigned int gpio)
 {
-    if (event_occurred[gpio]) {
-        event_occurred[gpio] = 0;
+    if (dyn_int_array_get(&event_occurred, gpio, 0)) {
+        dyn_int_array_set(&event_occurred, gpio, 0, 0);
         return 1;
     } else {
         return 0;
@@ -612,7 +624,7 @@ int blocking_wait_for_edge(unsigned int gpio, unsigned int edge)
         return 2;
 
     // export /sys/class/gpio interface
-    gpio_export(gpio);
+    gpio_export(gpio);  // ignore errors
     gpio_set_direction(gpio, 0); // 0=input
     gpio_set_edge(gpio, edge);
 
diff --git a/source/py_gpio.c b/source/py_gpio.c
index f8af6a0..3e19d21 100644
--- a/source/py_gpio.c
+++ b/source/py_gpio.c
@@ -45,7 +45,7 @@ SOFTWARE.
 static int gpio_warnings = 1;
 
 int max_gpio = -1;
-int *gpio_direction = NULL;
+void *gpio_direction = NULL;
 
 struct py_callback
 {
@@ -60,26 +60,15 @@ static struct py_callback *py_callbacks = NULL;
 
 static int init_module(void)
 {
-    int i;
-
-    max_gpio = 1024;
-    gpio_direction = (int *)malloc(max_gpio * sizeof(int));
-    for (i=0; i<max_gpio; i++)
-        gpio_direction[i] = -1;
-
     module_setup = 1;
 
     return 0;
 }
 
 
-static void set_gpio_direction(int gpio, int direction)
+static void remember_gpio_direction(int gpio, int direction)
 {
-  if (gpio >= max_gpio) {  /* Does gpio_direction need to be expanded? */
-    max_gpio = gpio + (gpio / 2);
-    gpio_direction = (int *)realloc(gpio_direction, max_gpio * sizeof(int));
-  }
-  gpio_direction[gpio] = direction;
+  dyn_int_array_set(&gpio_direction, gpio, direction, -1);
 }
 
 // python function cleanup()
@@ -124,21 +113,23 @@ static PyObject *py_setup_channel(PyObject *self, PyObject *args, PyObject *kwar
       return NULL;
    }
 
-   if (get_gpio_number(channel, &gpio))
-       return NULL;
-
-   gpio_export(gpio);
-   gpio_set_direction(gpio, direction);
-   // For some reason, the following code doesn't work for XIOs.  Skip.
-   if (!(gpio >= lookup_gpio_by_name("XIO-P0") && gpio <= lookup_gpio_by_name("XIO-P7"))) {
-     if (direction == OUTPUT) {
-         gpio_set_value(gpio, initial);
-     } else {
-         gpio_set_value(gpio, pud);
-     }
+   if (get_gpio_number(channel, &gpio)) {
+      PyErr_SetString(PyExc_ValueError, "Invalid value for channel");
+      return NULL;
    }
 
-   set_gpio_direction(gpio, direction);
+   int result = gpio_export(gpio);
+   if (result < 0) {
+      PyErr_SetString(PyExc_ValueError, "Channel in use (already exported)");
+      return NULL;
+   }
+   gpio_set_direction(gpio, direction);
+   // For some reason, the following code doesn't work for XIOs.  Skip.
+   if (direction == OUTPUT) {
+       gpio_set_value(gpio, initial);
+   }
+
+   remember_gpio_direction(gpio, direction);
 
    Py_RETURN_NONE;
 }
@@ -153,16 +144,22 @@ static PyObject *py_output_gpio(PyObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "si", &channel, &value))
         return NULL;
 
-    if (get_gpio_number(channel, &gpio))
+    if (get_gpio_number(channel, &gpio)) {
+        PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
         return NULL;
+    }
 
-    if (!module_setup || gpio_direction[gpio] != OUTPUT)
+    if (!module_setup || dyn_int_array_get(&gpio_direction, gpio, -1) != OUTPUT)
     {
         PyErr_SetString(PyExc_RuntimeError, "The GPIO channel has not been setup() as an OUTPUT");
         return NULL;
     }
 
-    gpio_set_value(gpio, value);
+    int result = gpio_set_value(gpio, value);
+    if (result < 0) {
+        PyErr_SetString(PyExc_RuntimeError, "Could not write to channel");
+        return NULL;
+    }
 
     Py_RETURN_NONE;
 }
@@ -178,11 +175,13 @@ static PyObject *py_input_gpio(PyObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "s", &channel))
         return NULL;
 
-    if (get_gpio_number(channel, &gpio))
+    if (get_gpio_number(channel, &gpio)) {
+        PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
         return NULL;
+    }
 
    // check channel is set up as an input or output
-    if (!module_setup || (gpio_direction[gpio] != INPUT && gpio_direction[gpio] != OUTPUT))
+    if (!module_setup || (dyn_int_array_get(&gpio_direction, gpio, -1) == -1))
     {
         PyErr_SetString(PyExc_RuntimeError, "You must setup() the GPIO channel first");
         return NULL;
@@ -282,8 +281,10 @@ static PyObject *py_add_event_callback(PyObject *self, PyObject *args, PyObject
       return NULL;
    }
 
-   if (get_gpio_number(channel, &gpio))
-       return NULL;
+    if (get_gpio_number(channel, &gpio)) {
+        PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
+        return NULL;
+    }
 
    // check to ensure gpio is one of the allowed pins
    if (gpio != lookup_gpio_by_name("AP-EINT3")
@@ -294,7 +295,7 @@ static PyObject *py_add_event_callback(PyObject *self, PyObject *args, PyObject
    }
 
    // check channel is set up as an input
-   if (!module_setup || gpio_direction[gpio] != INPUT)
+   if (!module_setup || dyn_int_array_get(&gpio_direction, gpio, -1) != INPUT)
    {
       PyErr_SetString(PyExc_RuntimeError, "You must setup() the GPIO channel as an input first");
       return NULL;
@@ -305,7 +306,6 @@ static PyObject *py_add_event_callback(PyObject *self, PyObject *args, PyObject
       PyErr_SetString(PyExc_RuntimeError, "Add event detection using add_event_detect first before adding a callback");
       return NULL;
    }
-
    if (add_py_callback(channel, gpio, bouncetime, cb_func) != 0)
       return NULL;
 
@@ -331,8 +331,10 @@ static PyObject *py_add_event_detect(PyObject *self, PyObject *args, PyObject *k
       return NULL;
    }
 
-   if (get_gpio_number(channel, &gpio))
+   if (get_gpio_number(channel, &gpio)) {
+       PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
        return NULL;
+   }
 
    // check to ensure gpio is one of the allowed pins
    if (gpio != lookup_gpio_by_name("AP-EINT3")
@@ -343,7 +345,7 @@ static PyObject *py_add_event_detect(PyObject *self, PyObject *args, PyObject *k
    }
 
    // check channel is set up as an input
-   if (!module_setup || gpio_direction[gpio] != INPUT)
+   if (!module_setup || dyn_int_array_get(&gpio_direction, gpio, -1) != INPUT)
    {
       PyErr_SetString(PyExc_RuntimeError, "You must setup() the GPIO channel as an input first");
       return NULL;
@@ -387,8 +389,10 @@ static PyObject *py_remove_event_detect(PyObject *self, PyObject *args)
    if (!PyArg_ParseTuple(args, "s", &channel))
       return NULL;
 
-   if (get_gpio_number(channel, &gpio))
-        return NULL;
+   if (get_gpio_number(channel, &gpio)) {
+       PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
+       return NULL;
+   }
 
    // check to ensure gpio is one of the allowed pins
    if (gpio != lookup_gpio_by_name("AP-EINT3")
@@ -431,8 +435,10 @@ static PyObject *py_event_detected(PyObject *self, PyObject *args)
    if (!PyArg_ParseTuple(args, "s", &channel))
       return NULL;
 
-   if (get_gpio_number(channel, &gpio))
+   if (get_gpio_number(channel, &gpio)) {
+       PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
        return NULL;
+   }
 
    if (event_detected(gpio))
       Py_RETURN_TRUE;
@@ -451,8 +457,10 @@ static PyObject *py_wait_for_edge(PyObject *self, PyObject *args)
    if (!PyArg_ParseTuple(args, "si", &channel, &edge))
       return NULL;
 
-   if (get_gpio_number(channel, &gpio))
-      return NULL;
+   if (get_gpio_number(channel, &gpio)) {
+       PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
+       return NULL;
+   }
 
    // check to ensure gpio is one of the allowed pins
    if (gpio != lookup_gpio_by_name("AP-EINT3")
@@ -463,7 +471,7 @@ static PyObject *py_wait_for_edge(PyObject *self, PyObject *args)
    }
 
    // check channel is setup as an input
-   if (!module_setup || gpio_direction[gpio] != INPUT)
+   if (!module_setup || dyn_int_array_get(&gpio_direction, gpio, -1) != INPUT)
    {
       PyErr_SetString(PyExc_RuntimeError, "You must setup() the GPIO channel as an input first");
       return NULL;
@@ -507,8 +515,10 @@ static PyObject *py_gpio_function(PyObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "s", &channel))
        return NULL;
 
-    if (get_gpio_number(channel, &gpio))
+    if (get_gpio_number(channel, &gpio)) {
+        PyErr_SetString(PyExc_RuntimeError, "Invalid channel");
         return NULL;
+    }
 
     if (setup_error)
     {
@@ -538,17 +548,105 @@ static PyObject *py_setwarnings(PyObject *self, PyObject *args)
 
 // Internal unit tests
 extern int num_get_xio_base;
+extern pins_t pins_info[];
 static PyObject *py_selftest(PyObject *self, PyObject *args)
 {
   int input;
   if (!PyArg_ParseTuple(args, "i", &input))
     return NULL;
 
+  printf("Testing get_xio_base\n");
   ASSRT(num_get_xio_base == 0);
   int base = get_xio_base();  ASSRT(base > 0 && base < 1024);
   ASSRT(num_get_xio_base == 1);
   int second_base = get_xio_base();  ASSRT(second_base == base);
   ASSRT(num_get_xio_base == 1);  /* make sure it didn't do the full calc a second time. */
+  printf("base=%d\n", base);
+
+  printf("Testing lookup_gpio_by_key\n");
+  ASSRT(0 == lookup_gpio_by_key("U13_1"));
+  ASSRT(48 == lookup_gpio_by_key("U13_9"));
+  ASSRT(47 == lookup_gpio_by_key("U13_11"));
+  ASSRT(base == lookup_gpio_by_key("U14_13"));
+  ASSRT((base+1) == lookup_gpio_by_key("U14_14"));
+  ASSRT((base+6) == lookup_gpio_by_key("U14_19"));
+  ASSRT((base+7) == lookup_gpio_by_key("U14_20"));
+  ASSRT(193 == lookup_gpio_by_key("U14_23"));
+  ASSRT(139 == lookup_gpio_by_key("U14_38"));
+  ASSRT(0 == lookup_gpio_by_key("U14_40"));
+  ASSRT(0 == lookup_gpio_by_key("NOTFOUND"));
+  ASSRT(0 == lookup_gpio_by_key("U14_"));
+  ASSRT(0 == lookup_gpio_by_key("U14_4000"));
+
+  printf("Testing lookup_gpio_by_name\n");
+  ASSRT(0 == lookup_gpio_by_name("GND"));
+  ASSRT(48 == lookup_gpio_by_name("TWI1-SDA"));
+  ASSRT(47 == lookup_gpio_by_name("TWI1-SCK"));
+  ASSRT(base == lookup_gpio_by_name("XIO-P0"));
+  ASSRT((base+6) == lookup_gpio_by_name("XIO-P6"));
+  ASSRT((base+7) == lookup_gpio_by_name("XIO-P7"));
+  ASSRT(139 == lookup_gpio_by_name("CSID7"));
+  ASSRT(0 == lookup_gpio_by_name("NOTFOUND"));
+  ASSRT(0 == lookup_gpio_by_name("CSID"));
+  ASSRT(0 == lookup_gpio_by_name("CSID777"));
+
+  printf("Testing lookup_ain_by_key\n");
+  ASSRT(-1 == lookup_ain_by_key("U14_1"));
+  ASSRT(0 == lookup_ain_by_key("U14_11"));
+  ASSRT(-1 == lookup_ain_by_key("NOTFOUND"));
+  ASSRT(-1 == lookup_ain_by_key("U14_"));
+  ASSRT(-1 == lookup_ain_by_key("U14_1111"));
+
+  printf("Testing lookup_ain_by_name\n");
+  ASSRT(-1 == lookup_ain_by_name("GND"));
+  ASSRT(0 == lookup_ain_by_name("LRADC"));
+  ASSRT(-1 == lookup_ain_by_name("NOTFOUND"));
+  ASSRT(-1 == lookup_ain_by_name("LR"));
+  ASSRT(-1 == lookup_ain_by_name("LRADCCC"));
+
+  char k[9];
+
+  printf("Testing copy_key_by_key\n");
+  ASSRT(1 == copy_key_by_key("U13_1", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U13_1", k));
+  ASSRT(1 == copy_key_by_key("U14_40", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U14_40", k));
+  ASSRT(0 == copy_key_by_key("NOTFOUND", k));
+  ASSRT(0 == copy_key_by_key("U14_", k));
+  ASSRT(0 == copy_key_by_key("U14_4000", k));
+
+  printf("Testing copy_pwm_key_by_key\n");
+  ASSRT(1 == copy_pwm_key_by_key("U13_18", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U13_18", k));
+  ASSRT(0 == copy_pwm_key_by_key("U13_1", k));
+  ASSRT(0 == copy_pwm_key_by_key("U14_40", k));
+  ASSRT(0 == copy_pwm_key_by_key("NOTFOUND", k));
+  ASSRT(0 == copy_pwm_key_by_key("U13_", k));
+  ASSRT(0 == copy_pwm_key_by_key("U13_1888", k));
+
+  printf("Testing get_key_by_name\n");
+  ASSRT(1 == get_key_by_name("GND", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U13_1", k));
+  ASSRT(1 == get_key_by_name("CSID7", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U14_38", k));
+  ASSRT(0 == get_key_by_name("NOTFOUND", k));
+  ASSRT(0 == get_key_by_name("CSID", k));
+  ASSRT(0 == get_key_by_name("CSID777", k));
+
+  printf("Testing get_pwm_key_by_name\n");
+  ASSRT(1 == get_pwm_key_by_name("PWM0", k)); BUF2SMALL(k); ASSRT(0 == strcmp("U13_18", k));
+  ASSRT(0 == get_pwm_key_by_name("NOTFOUND", k));
+  ASSRT(0 == get_pwm_key_by_name("PWM", k));
+  ASSRT(0 == get_pwm_key_by_name("PWM000", k));
+
+  char fp[80];
+
+  printf("Testing build_path\n");
+  ASSRT(1 == build_path("/home", "ch", fp, sizeof(fp)));  ASSRT(0 == strcmp("/home/chip", fp));
+  ASSRT(1 == build_path("/home", "chip", fp, sizeof(fp)));  ASSRT(0 == strcmp("/home/chip", fp));
+  ASSRT(0 == build_path("/home", "NOTFOUND", fp, sizeof(fp)));
+  ASSRT(0 == build_path("/home", "chipp", fp, sizeof(fp)));
+  ASSRT(0 == build_path("/home", "ip", fp, sizeof(fp)));
+  ASSRT(0 == build_path("/NOTFOUND", "ch", fp, sizeof(fp)));
+
+  printf("Testing get_spi_bus_path_number\n");
+  ASSRT(2 == get_spi_bus_path_number(0));  /* doesn't really work on CHIP */
+  ASSRT(2 == get_spi_bus_path_number(1));  /* doesn't really work on CHIP */
 
   int value = input;
 
diff --git a/source/py_softpwm.c b/source/py_softpwm.c
index 8be3037..514c2ae 100644
--- a/source/py_softpwm.c
+++ b/source/py_softpwm.c
@@ -32,13 +32,13 @@ SOFTWARE.
 #include "Python.h"
 #include "constants.h"
 #include "common.h"
-#include "c_softpwm.h"
+#include "c_softpwm.h"
 
 // python function cleanup()
 static PyObject *py_cleanup(PyObject *self, PyObject *args)
 {
     // unexport the PWM
-    softpwm_cleanup();
+    softpwm_cleanup();
 
     Py_RETURN_NONE;
 }
@@ -47,7 +47,7 @@ static PyObject *py_cleanup(PyObject *self, PyObject *args)
 static PyObject *py_start_channel(PyObject *self, PyObject *args, PyObject *kwargs)
 {
     char key[8];
-    char *channel;
+    char *channel = NULL;
     float frequency = 2000.0;
     float duty_cycle = 0.0;
     int polarity = 0;
@@ -56,6 +56,7 @@ static PyObject *py_start_channel(PyObject *self, PyObject *args, PyObject *kwar
     if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|ffi", kwlist, &channel, &duty_cycle, &frequency, &polarity)) {
         return NULL;
     }
+    ASSRT(channel != NULL);
 
     if (!get_key(channel, key)) {
         PyErr_SetString(PyExc_ValueError, "Invalid SOFTPWM key or name.");
@@ -79,7 +80,7 @@ static PyObject *py_start_channel(PyObject *self, PyObject *args, PyObject *kwar
         return NULL;
     }
 
-    if (!softpwm_start(key, duty_cycle, frequency, polarity))
+    if (!softpwm_start(key, duty_cycle, frequency, polarity))
         return NULL;
 
     Py_RETURN_NONE;
@@ -94,12 +95,12 @@ static PyObject *py_stop_channel(PyObject *self, PyObject *args, PyObject *kwarg
     if (!PyArg_ParseTuple(args, "s", &channel))
         return NULL;
 
-    if (!get_key(channel, key)) {
+    if (!get_key(channel, key)) {
         PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
         return NULL;
     }
 
-    softpwm_disable(key);
+    softpwm_disable(key);
 
     Py_RETURN_NONE;
 }
@@ -121,12 +122,12 @@ static PyObject *py_set_duty_cycle(PyObject *self, PyObject *args, PyObject *kwa
         return NULL;
     }
 
-    if (!get_key(channel, key)) {
+    if (!get_key(channel, key)) {
         PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
         return NULL;
     }
 
-    if (softpwm_set_duty_cycle(key, duty_cycle) == -1) {
+    if (softpwm_set_duty_cycle(key, duty_cycle) == -1) {
         PyErr_SetString(PyExc_RuntimeError, "You must start() the PWM channel first");
         return NULL;
     }
@@ -145,13 +146,13 @@ static PyObject *py_set_frequency(PyObject *self, PyObject *args, PyObject *kwar
     if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|f", kwlist, &channel, &frequency))
         return NULL;
 
-    if ((frequency <= 0.0) || (frequency > 10000.0))
+    if ((frequency <= 0.0) || (frequency > 10000.0))
     {
-        PyErr_SetString(PyExc_ValueError, "frequency must be greater than 0.0 and less than 10000.0");
+        PyErr_SetString(PyExc_ValueError, "frequency must be greater than 0.0 and less than 10000.0");
         return NULL;
     }
 
-    if (!get_key(channel, key)) {
+    if (!get_key(channel, key)) {
         PyErr_SetString(PyExc_ValueError, "Invalid PWM key or name.");
         return NULL;
     }
diff --git a/test/.ropeproject/config.py b/test/.ropeproject/config.py
new file mode 100644
index 0000000..3745e30
--- /dev/null
+++ b/test/.ropeproject/config.py
@@ -0,0 +1,96 @@
+# The default ``config.py``
+
+
+def set_prefs(prefs):
+    """This function is called before opening the project"""
+
+    # Specify which files and folders to ignore in the project.
+    # Changes to ignored resources are not added to the history and
+    # VCSs.  Also they are not returned in `Project.get_files()`.
+    # Note that ``?`` and ``*`` match all characters but slashes.
+    # '*.pyc': matches 'test.pyc' and 'pkg/test.pyc'
+    # 'mod*.pyc': matches 'test/mod1.pyc' but not 'mod/1.pyc'
+    # '.svn': matches 'pkg/.svn' and all of its children
+    # 'build/*.o': matches 'build/lib.o' but not 'build/sub/lib.o'
+    # 'build//*.o': matches 'build/lib.o' and 'build/sub/lib.o'
+    prefs['ignored_resources'] = [
+        '*.pyc', '*~', '.ropeproject', '.hg', '.svn', '_svn', '.git',
+        '.tox', '.env', 'node_modules', 'bower_components']
+
+    # Specifies which files should be considered python files.  It is
+    # useful when you have scripts inside your project.  Only files
+    # ending with ``.py`` are considered to be python files by
+    # default.
+    #prefs['python_files'] = ['*.py']
+
+    # Custom source folders:  By default rope searches the project
+    # for finding source folders (folders that should be searched
+    # for finding modules).  You can add paths to that list.  Note
+    # that rope guesses project source folders correctly most of the
+    # time; use this if you have any problems.
+    # The folders should be relative to project root and use '/' for
+    # separating folders regardless of the platform rope is running on.
+    # 'src/my_source_folder' for instance.
+    #prefs.add('source_folders', 'src')
+
+    # You can extend python path for looking up modules
+    #prefs.add('python_path', '~/python/')
+
+    # Should rope save object information or not.
+    prefs['save_objectdb'] = True
+    prefs['compress_objectdb'] = False
+
+    # If `True`, rope analyzes each module when it is being saved.
+    prefs['automatic_soa'] = True
+    # The depth of calls to follow in static object analysis
+    prefs['soa_followed_calls'] = 0
+
+    # If `False` when running modules or unit tests "dynamic object
+    # analysis" is turned off.  This makes them much faster.
+    prefs['perform_doa'] = True
+
+    # Rope can check the validity of its object DB when running.
+    prefs['validate_objectdb'] = True
+
+    # How many undos to hold?
+    prefs['max_history_items'] = 32
+
+    # Shows whether to save history across sessions.
+    prefs['save_history'] = True
+    prefs['compress_history'] = False
+
+    # Set the number spaces used for indenting.  According to
+    # :PEP:`8`, it is best to use 4 spaces.  Since most of rope's
+    # unit-tests use 4 spaces it is more reliable, too.
+    prefs['indent_size'] = 4
+
+    # Builtin and c-extension modules that are allowed to be imported
+    # and inspected by rope.
+    prefs['extension_modules'] = []
+
+    # Add all standard c-extensions to extension_modules list.
+    prefs['import_dynload_stdmods'] = True
+
+    # If `True` modules with syntax errors are considered to be empty.
+    # The default value is `False`; When `False` syntax errors raise
+    # `rope.base.exceptions.ModuleSyntaxError` exception.
+    prefs['ignore_syntax_errors'] = False
+
+    # If `True`, rope ignores unresolvable imports.  Otherwise, they
+    # appear in the importing namespace.
+    prefs['ignore_bad_imports'] = False
+
+    # If `True`, rope will transform a comma list of imports into
+    # multiple separate import statements when organizing
+    # imports.
+    prefs['split_imports'] = False
+
+    # If `True`, rope will sort imports alphabetically by module name
+    # instead of alphabetically by import statement, with from imports
+    # after normal imports.
+    prefs['sort_imports_alphabetically'] = False
+
+
+def project_opened(project):
+    """This function is called after opening the project"""
+    # Do whatever you like here!
diff --git a/test/.ropeproject/globalnames b/test/.ropeproject/globalnames
new file mode 100644
index 0000000..02f3a4d
--- /dev/null
+++ b/test/.ropeproject/globalnames
@@ -0,0 +1,2 @@
+�}q
(Utest_softpwm_setup]q(Uteardown_moduleqUTestSoftpwmSetupqeUtest_gpio_output]q(hUTestGPIOOutputqeUtest_pwm_setup]q(hUTestPwmSetupqeUtest_gpio_setup]q	(hU	TestSetupq
+eUtest_gpio_input]q(hU
TestGPIOInputqeUgptest]q
(U
fUloopfunctionqU
num_callbacksqUedgeqU
tUloopfunction_exitqU
myfuncallbackqeu.
\ No newline at end of file
diff --git a/test/.ropeproject/history b/test/.ropeproject/history
new file mode 100644
index 0000000..fcd9c96
--- /dev/null
+++ b/test/.ropeproject/history
@@ -0,0 +1 @@
+�]q
(]q]qe.
\ No newline at end of file
diff --git a/test/.ropeproject/objectdb b/test/.ropeproject/objectdb
new file mode 100644
index 0000000..87a3774
--- /dev/null
+++ b/test/.ropeproject/objectdb
@@ -0,0 +1,5 @@
+�}q
US/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py}q(U
Thread._blockcrope.base.oi.memorydb
+ScopeInfo
+q)�q}qUinstanceqUdefinedqUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyUThreadq���hhUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyU
+_Conditionq	��s}q
+�bUThread._set_daemonh)�q}qhhUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyh���hUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyU
Thread.daemon�s}q
�bU
currentThreadqh)�q}q)hhUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyU_DummyThreadq��s}q�bU	Conditionqh)�q}qUunknown�q�hhUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyh	��s}q�bUEventqh)�q}q)hhUS/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyU_Eventq��s}q�bus.
\ No newline at end of file
diff --git a/test/gptest.py b/test/gptest.py
index 58750a2..9e0720f 100755
--- a/test/gptest.py
+++ b/test/gptest.py
@@ -1,27 +1,49 @@
 #!/usr/bin/python
 
 import CHIP_IO.GPIO as GPIO
-import time, os, threading
+import time
+import threading
+
+num_callbacks = 0
+
 
 def myfuncallback(channel):
+    global num_callbacks
+    num_callbacks += 1
     print "CALLBACK LIKE DRAKE IN HOTLINE BLING"
-    
+
+
+loopfunction_exit = False
+
+
 def loopfunction():
     print "LOOP FUNCTION"
-    for i in xrange(20):
+    for i in xrange(4):
+        if loopfunction_exit:
+            break
         if i % 2:
-            print "SETTING CSID0 LOW"
-            GPIO.output("CSID0",GPIO.LOW)
+            print "SETTING CSID0 LOW (i=", i, ")"
+            GPIO.output("CSID0", GPIO.LOW)
         else:
-            print "SETTING CSID0 HIGH"
-            GPIO.output("CSID0",GPIO.HIGH)
+            print "SETTING CSID0 HIGH (i=", i, ")"
+            GPIO.output("CSID0", GPIO.HIGH)
         print "SLEEPING"
         time.sleep(1)
-    
-print "SETUP XIO-P0"
-GPIO.setup("XIO-P0", GPIO.IN)
 
-print "SETUP CSID0"
+
+GPIO.selftest(0)
+
+GPIO.setup("XIO-P0", GPIO.IN)
+GPIO.setup("CSID0", GPIO.OUT, initial=GPIO.HIGH)
+assert(GPIO.input("XIO-P0") == GPIO.HIGH)
+GPIO.cleanup()
+
+GPIO.setup("XIO-P0", GPIO.IN)
+GPIO.setup("CSID0", GPIO.OUT, initial=GPIO.LOW)
+assert(GPIO.input("XIO-P0") == GPIO.LOW)
+GPIO.cleanup()
+
+GPIO.setup("XIO-P0", GPIO.IN)
 GPIO.setup("CSID0", GPIO.OUT)
 
 # VERIFY SIMPLE FUNCTIONALITY
@@ -29,51 +51,57 @@ print "VERIFY SIMPLE FUNCTIONALITY"
 
 print "READING XIO-PI"
 GPIO.output("CSID0", GPIO.HIGH)
-print "HIGH", GPIO.input("XIO-P0")
+assert(GPIO.input("XIO-P0") == GPIO.HIGH)
 
 GPIO.output("CSID0", GPIO.LOW)
 print "LOW", GPIO.input("XIO-P0")
+assert(GPIO.input("XIO-P0") == GPIO.LOW)
 
 # ==============================================
 # EDGE DETECTION - AP-EINT1
 print "SETTING UP EDGE DETECTION ON AP-EINT1"
 GPIO.setup("AP-EINT1", GPIO.IN)
-GPIO.add_event_detect("AP-EINT1",GPIO.FALLING)
+print "adding event detect"
+GPIO.add_event_detect("AP-EINT1", GPIO.RISING)
 
 print "VERIFYING EDGE DETECT"
-f = open("/sys/class/gpio/gpio193/edge","r")
+f = open("/sys/class/gpio/gpio193/edge", "r")
 edge = f.read()
 f.close()
-print "EDGE: %s" % edge
+print "edge='", edge, "'"
+assert(edge == "rising\n")
 GPIO.remove_event_detect("AP-EINT1")
 
 # ==============================================
 # EDGE DETECTION - AP-EINT3
 print "SETTING UP EDGE DETECTION ON AP-EINT3"
 GPIO.setup("AP-EINT3", GPIO.IN)
-GPIO.add_event_detect("AP-EINT3",GPIO.FALLING)
+GPIO.add_event_detect("AP-EINT3", GPIO.BOTH)
 
 print "VERIFYING EDGE DETECT"
-f = open("/sys/class/gpio/gpio35/edge","r")
+f = open("/sys/class/gpio/gpio35/edge", "r")
 edge = f.read()
 f.close()
 print "EDGE: %s" % edge
+assert(edge == "both\n")
 GPIO.remove_event_detect("AP-EINT3")
 
 # ==============================================
 # EDGE DETECTION - EXPANDED GPIO
 print "SETTING UP EDGE DETECTION ON XIO-P0"
-GPIO.add_event_detect("XIO-P0",GPIO.FALLING,myfuncallback)
+GPIO.add_event_detect("XIO-P0", GPIO.FALLING, myfuncallback)
 
 print "VERIFYING EDGE DETECT"
-f = open("/sys/class/gpio/gpio408/edge","r")
+f = open("/sys/class/gpio/gpio408/edge", "r")
 edge = f.read()
 f.close()
 print "EDGE: %s" % edge
+assert(edge == "falling\n")
 
 # LOOP WRITING ON CSID0 TO HOPEFULLY GET CALLBACK TO WORK
 print "WAITING FOR CALLBACKS"
 loopfunction()
+print "num_callbacks=", num_callbacks
 
 print "PRESS CONTROL-C TO EXIT IF SCRIPT GETS STUCK"
 GPIO.remove_event_detect("XIO-P0")
@@ -82,18 +110,30 @@ try:
     t = threading.Thread(target=loopfunction)
     t.start()
     print "WAITING FOR EDGE"
-    GPIO.wait_for_edge("XIO-P0",GPIO.FALLING)
+    GPIO.wait_for_edge("XIO-P0", GPIO.FALLING)
     print "WE'VE FALLEN LIKE COOLIO'S CAREER"
-    print "ATTEMPTING TO CANCEL THE TIMER"
-    t.cancel()
 except:
     pass
 
+print "Exit thread"
+loopfunction_exit = True
+t.join()  # Wait till the thread exits.
+GPIO.remove_event_detect("XIO-P0")
+
 print "TESTING ERRORS THROWN WHEN SPECIFYING EDGE DETECTION ON UNAUTHORIZED GPIO"
-GPIO.setup("CSID1",GPIO.IN)
-GPIO.add_event_detect("CSID1",GPIO.FALLING,myfuncallback)
+GPIO.setup("CSID1", GPIO.IN)
+try:
+    GPIO.add_event_detect("CSID1", GPIO.FALLING, myfuncallback)
+    print "Oops, it did not throw an exception!  BUG!!!"
+except:
+    pass
+
+print "TESTING ERRORS THROWN WHEN WRITING TO A GPIO WITH NO DIRECTION"
+try:
+    GPIO.output("CSID1", GPIO.LOW)
+    print "Oops, it did not throw an exception!  BUG!!!"
+except:
+    pass
 
 print "CLEANUP"
-GPIO.remove_event_detect("XIO-P0")
 GPIO.cleanup()
-
diff --git a/unexport_all.sh b/unexport_all.sh
new file mode 100755
index 0000000..bf497e6
--- /dev/null
+++ b/unexport_all.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+for F in /sys/class/gpio/gpio[0-9]*; do :
+  GPIO=`echo $F | sed 's/^[^0-9]*//'`
+  echo $F $GPIO
+  echo $GPIO >/sys/class/gpio/unexport
+done