cleanup of brettcvz's read_byte function, added read_word since he really needs 12 bits of data. finally fixed the gpio cleanup() without argument issue once and for all, sorry for lying howientc

CHANGELOG.rst

@@ -1,3 +1,10 @@
+0.3.5
+---
+* Merged in brettcvz's code to read a byte of data from the GPIO
+  - Cleaned the code up and expanded it (in the low level C code) to read up to 32 bits of data
+  - Presented 8 bit and 16 bits of data functions to the Python interface with brettcvz's read_byte() and my read_word()
+* I think I finally fixed the GPIO.cleanup() code one and for all
+
 0.3.4.1
 ---
 * Quick fix as I borked XIO setup as inputs with the latest change that enabled PUD

README.rst

@@ -205,6 +205,15 @@ Polling inputs::
     else:
         print("LOW")
 
+Read lots of data::
+
+    # Get 8 bits of data in one shot
+    mybyte = GPIO.read_byte("LCD-D3")
+    # Get 16 bits of data in one shot
+    myword = GPIO.read_word("XIO-P4")
+
+This code was initially added by brettcvz and I cleaned it up and expanded it.
+
 The edge detection code below only works for the AP-EINT1, AP-EINT3, and XPO Pins on the CHIP.
 
 Waiting for an edge (GPIO.RISING, GPIO.FALLING, or GPIO.BOTH::

setup.py

@@ -20,7 +20,7 @@ classifiers = ['Development Status :: 3 - Alpha',
                'Topic :: System :: Hardware']
 
 setup(name             = 'CHIP_IO',
-      version          = '0.3.4.1',
+      version          = '0.3.5',
       author           = 'Robert Wolterman',
       author_email     = 'robert.wolterman@gmail.com',
       description      = 'A module to control CHIP IO channels',

source/constants.c

@@ -88,6 +88,6 @@ void define_constants(PyObject *module)
    module_debug = Py_BuildValue("i", DEBUG ? Py_True: Py_False);
    PyModule_AddObject(module, "DEBUG", module_debug);
 
-   version = Py_BuildValue("s", "0.3.4.1");
+   version = Py_BuildValue("s", "0.3.5");
    PyModule_AddObject(module, "VERSION", version);
 }

source/event_gpio.c

@@ -506,8 +506,7 @@ int gpio_get_value(int gpio, unsigned int *value)
     int fd = fd_lookup(gpio);
     char ch;
 
-    if (!fd)
+    if (!fd) {
-    {
         if ((fd = open_value_file(gpio)) == -1) {
             char err[256];
             snprintf(err, sizeof(err), "gpio_get_value: could not open GPIO %d value file", gpio);
@@ -547,6 +546,58 @@ int gpio_get_value(int gpio, unsigned int *value)
     return 0;
 }
 
+int gpio_get_more(int gpio, int bits, unsigned int *value)
+{
+    int fd = fd_lookup(gpio);
+    char ch;
+    
+    if (!fd) {
+        if ((fd = open_value_file(gpio)) == -1) {
+            char err[256];
+            snprintf(err, sizeof(err), "gpio_get_more: could not open GPIO %d value file", gpio);
+            add_error_msg(err);
+            return -1;
+        }
+    }
+
+    // Loop for our number of bits
+    int i;
+    for (i = 0; i < bits; i++) {
+
+        if (lseek(fd, 0, SEEK_SET) < 0) {
+            char err[256];
+            snprintf(err, sizeof(err), "gpio_get_more: could not seek GPIO %d (%s)", gpio, strerror(errno));
+            add_error_msg(err);
+            return -1;
+        }
+        ssize_t s = read(fd, &ch, sizeof(ch));
+        if (s < 0) {
+            char err[256];
+            snprintf(err, sizeof(err), "gpio_get_more: could not read GPIO %d (%s)", gpio, strerror(errno));
+            add_error_msg(err);
+            return -1;
+        }
+    
+        if (ch == '1') {
+            *value |= (1 << i);
+        } else if (ch == '0') {
+            *value |= (0 << i);
+        } else {
+            char err[256];
+            snprintf(err, sizeof(err), "gpio_get_more: unrecognized read GPIO %d (%c)", gpio, ch);
+            add_error_msg(err);
+            return -1;
+        }
+        if (DEBUG) {
+            printf(" ** gpio_get_more: %c **\n", ch);
+            printf(" ** gpio_get_more: current value: %u **\n", *value);
+        }
+    }
+
+    return 0;
+    
+}
+
 int gpio_set_edge(int gpio, unsigned int edge)
 {
     int fd;

source/event_gpio.h

@@ -69,6 +69,7 @@ int gpio_set_direction(int gpio, unsigned int in_flag);
 int gpio_get_direction(int gpio, unsigned int *value);
 int gpio_set_value(int gpio, unsigned int value);
 int gpio_get_value(int gpio, unsigned int *value);
+int gpio_get_more(int gpio, int bits, unsigned int *value);
 int fd_lookup(int gpio);
 int open_value_file(int gpio);
 

source/py_gpio.c

@@ -86,7 +86,6 @@ static int init_module(void)
     return 0;
 }
 
-
 static void remember_gpio_direction(int gpio, int direction)
 {
     dyn_int_array_set(&gpio_direction, gpio, direction, -1);
@@ -118,10 +117,7 @@ static PyObject *py_cleanup(PyObject *self, PyObject *args, PyObject *kwargs)
         event_cleanup();
     } else {
         if (get_gpio_number(channel, &gpio) < 0) {
-            char err[2000];
+            event_cleanup();
-            snprintf(err, sizeof(err), "Invalid channel %s. (%s)", channel, get_error_msg());
-            PyErr_SetString(PyExc_ValueError, err);
-            return NULL;
         }
         gpio_unexport(gpio);
     }
@@ -290,13 +286,12 @@ static PyObject *py_input_gpio(PyObject *self, PyObject *args)
     return py_value;
 }
 
+//TODO: Come up with a way to merge py_read_byte_gpio and py_read_word_gpio
 // python function value = read_byte(channel)
 static PyObject *py_read_byte_gpio(PyObject *self, PyObject *args)
 {
     int gpio;
     char *channel;
-    int i;
-    unsigned int bit;
     unsigned int value = 0;
     PyObject *py_value;
 
@@ -306,37 +301,63 @@ static PyObject *py_read_byte_gpio(PyObject *self, PyObject *args)
         return NULL;
 
     if (get_gpio_number(channel, &gpio)) {
-    }
-
-    if (strcmp(channel, "XIO") == 0) {
-      int base_gpio = get_xio_base();
-      for (i = 0; i < 8; i++) {
-        gpio = base_gpio + i;
-        if (gpio_get_value(gpio, &bit) < 0) {
-          char err[1024];
-          snprintf(err, sizeof(err), "Could not get bit ('%s')", get_error_msg());
-          PyErr_SetString(PyExc_RuntimeError, err);
-          return NULL;
-        }
-        value |= (bit << i);
-      }
-    } else if (strcmp(channel, "CSID") == 0) {
-      int base_gpio = 132;
-      for (i = 0; i < 8; i++) {
-        gpio = base_gpio + i;
-        if (gpio_get_value(gpio, &bit) < 0) {
-          char err[1024];
-          snprintf(err, sizeof(err), "Could not get bit ('%s')", get_error_msg());
-          PyErr_SetString(PyExc_RuntimeError, err);
-          return NULL;
-        }
-        value |= (bit << i);
-      }
-    } else {
         PyErr_SetString(PyExc_ValueError, "Invalid channel");
         return NULL;
     }
 
+   // check channel is set up as an input or 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;
+    }
+
+    // We only want to get a 8 bits here
+    if (gpio_get_more(gpio, 8, &value) < 0) {
+      char err[1024];
+      snprintf(err, sizeof(err), "Could not get 8 bits of data ('%s')", get_error_msg());
+      PyErr_SetString(PyExc_RuntimeError, err);
+      return NULL;
+    }
+
+    py_value = Py_BuildValue("i", value);
+
+    return py_value;
+}
+
+// python function value = read_word(channel)
+static PyObject *py_read_word_gpio(PyObject *self, PyObject *args)
+{
+    int gpio;
+    char *channel;
+    unsigned int value = 0;
+    PyObject *py_value;
+
+    clear_error_msg();
+
+    if (!PyArg_ParseTuple(args, "s", &channel))
+        return NULL;
+
+    if (get_gpio_number(channel, &gpio)) {
+        PyErr_SetString(PyExc_ValueError, "Invalid channel");
+        return NULL;
+    }
+
+   // check channel is set up as an input or 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;
+    }
+
+    // We only want to get a 8 bits here
+    if (gpio_get_more(gpio, 16, &value) < 0) {
+      char err[1024];
+      snprintf(err, sizeof(err), "Could not get 16 bits of data ('%s')", get_error_msg());
+      PyErr_SetString(PyExc_RuntimeError, err);
+      return NULL;
+    }
+
     py_value = Py_BuildValue("i", value);
 
     return py_value;
@@ -912,7 +933,8 @@ PyMethodDef gpio_methods[] = {
    {"cleanup", (PyCFunction)py_cleanup, METH_VARARGS | METH_KEYWORDS, "Clean up by resetting all GPIO channels that have been used by this program to INPUT with no pullup/pulldown and no event detection"},
    {"output", py_output_gpio, METH_VARARGS, "Output to a GPIO channel\ngpio  - gpio channel\nvalue - 0/1 or False/True or LOW/HIGH"},
    {"input", py_input_gpio, METH_VARARGS, "Input from a GPIO channel.  Returns HIGH=1=True or LOW=0=False\ngpio - gpio channel"},
-   {"read_byte", py_read_byte_gpio, METH_VARARGS, "Read a byte from a set of GPIO channels. Returns 8-bit integer\ngpio - gpio channel. Valid channels: 'XIO', 'CSID'"},
+   {"read_byte", py_read_byte_gpio, METH_VARARGS, "Read a byte (8 bits) from a set of GPIO channels. Returns 8-bits of integer data\ngpio - gpio channel."},
+   {"read_word", py_read_word_gpio, METH_VARARGS, "Read a word (16 bits) from a set of GPIO channels. Returns 16-bits of integer data\ngpio - gpio channel."},
    {"add_event_detect", (PyCFunction)py_add_event_detect, METH_VARARGS | METH_KEYWORDS, "Enable edge detection events for a particular GPIO channel.\nchannel      - either board pin number or BCM number depending on which mode is set.\nedge         - RISING, FALLING or BOTH\n[callback]   - A callback function for the event (optional)\n[bouncetime] - Switch bounce timeout in ms for callback"},
    {"remove_event_detect", py_remove_event_detect, METH_VARARGS, "Remove edge detection for a particular GPIO channel\ngpio - gpio channel"},
    {"event_detected", py_event_detected, METH_VARARGS, "Returns True if an edge has occured on a given GPIO.  You need to enable edge detection using add_event_detect() first.\ngpio - gpio channel"},

source/py_softpwm.c

@@ -62,8 +62,7 @@ static PyObject *py_cleanup(PyObject *self, PyObject *args)
         return NULL;
     } else {
         if (!get_key(channel, key)) {
-            PyErr_SetString(PyExc_ValueError, "Invalid SOFTPWM key or name.");
+            softpwm_cleanup();
-            return NULL;
         }
         softpwm_disable(key);
     }