Merge branch 'pwm' into for-pull

api/maa.h

@@ -27,6 +27,7 @@
 #include "i2c.h"
 #include "i2cslave.h"
 #include "gpio.h"
+#include "pwm.h"
 
 #define MAA_LIBRARY_VERSION 1
 

api/pwm.h

@@ -0,0 +1,139 @@
+/*
+ * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
+ *
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdio.h>
+#include <fcntl.h>
+
+namespace maa {
+
+/** A PWM object, used for interacting with PWM output.
+ *
+ * Example:
+ * @code
+ * // Set up PWM object then cycle percentage 0-100.
+ *
+ * #include "maa.h"
+ *
+ * PWM pwm(3);
+ *
+ * int main() {
+ *     pwm.period_us(7968750i); //Max Galileo Rev D
+ *     pwm.enable(1);
+ *
+ *     float value = 0;
+ *     while(1) {
+ *         pwm.write(value);
+ *         sleep(0.5);
+ *         if(value == 1.0) {
+ *             value = 0;
+ *         } else {
+ *             value = value +0.1;
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
+class PWM {
+
+private:
+    int chipid, pin;
+    FILE *duty_fp;
+
+    void write_period(int period);
+    void write_duty(int duty);
+    int setup_duty_fp();
+    int get_period();
+    int get_duty();
+
+public:
+
+    /** Create an PWM object
+     *
+     *  @param chipid The chip in which the following pin is on.
+     *  @param pin The PWM channel to operate on
+     */
+    PWM(int chipid, int pin);
+
+    /** Set the ouput duty-cycle percentage, as a float
+     *
+     *  @param percentage A floating-point value representing percentage of output.
+     *    The value should lie between 0.0f (representing on 0%) and 1.0f
+     *    Values above or below this range will be set at either 0.0f or 1.0f.
+     */
+    void write(float percentage);
+
+    /** Read the ouput duty-cycle percentage, as a float
+     *
+     *  @return percentage A floating-point value representing percentage of output.
+     *    The value should lie between 0.0f (representing on 0%) and 1.0f
+     *    Values above or below this range will be set at either 0.0f or 1.0f.
+     */
+    float read();
+
+    /** Set the PWM period as seconds represented in a float
+     *
+     *  @param seconds Peroid represented as a float in seconds.
+     */
+    void period(float seconds);
+
+    /** Set period. milli-oseconds.
+     *  @param ms milli-seconds for period.
+     */
+    void period_ms(int ms);
+
+    /** Set period. microseconds
+     *  @param ns microseconds as period.
+     */
+    void period_us(int us);
+
+    /** Set pulsewidth, As represnted by seconds in a (float).
+     *  @param seconds The duration of a pulse
+     */
+    void pulsewidth(float seconds);
+
+     /** Set pulsewidth. Milliseconds
+     *  @param ms milliseconds for pulsewidth.
+     */
+    void pulsewidth_ms(int ms);
+
+      /** Set pulsewidth, microseconds.
+     *  @param us microseconds for pulsewidth.
+     */
+    void pulsewidth_us(int us);
+
+    /** Set the enable status of the PWM pin. None zero will assume on with output being driven.
+     *   and 0 will disable the output.
+     *  @param enable enable status of pin
+     */
+    void enable(int enable);
+
+     /** Close and unexport the PWM pin.
+     */
+    void close();
+
+};
+}

examples/CMakeLists.txt

@@ -1,7 +1,9 @@
 add_executable (readi2c readi2c.cpp)
 add_executable (hellomaa hellomaa.cpp)
+add_executable (cycle-pwm3 cycle-pwm3.cpp)
 
 include_directories(${PROJECT_SOURCE_DIR}/api ${PROJECT_SOURCE_DIR}/include)
 
 target_link_libraries (hellomaa maa)
 target_link_libraries (readi2c maa)
+target_link_libraries (cycle-pwm3 maa)

examples/cycle-pwm3.cpp

@@ -0,0 +1,24 @@
+#include <unistd.h>
+
+#include "maa.h"
+
+int
+main ()
+{
+  maa::PWM pwm(0, 3);
+  pwm.period_us(200);
+  pwm.enable(1);
+
+  float value = 0.0f;
+
+  while(1) {
+    value = value + 0.01f;
+    pwm.write(value);
+    usleep(50000);
+    if (value >= 1.0f) {
+        value = 0.0f;
+    }
+    float output = pwm.read();
+  }
+  return 0;
+}

examples/python/cycle-pwm3.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+
+import pymaa as maa
+import time
+
+x = maa.PWM(0,3)
+x.enable(1);
+x.period_us(20)
+value= 0.0
+
+while True:
+    x.write(value)
+    time.sleep(0.2)
+    value = value +0.01
+    if value >= 1:
+        value = 0.0

src/CMakeLists.txt

@@ -9,6 +9,7 @@ set (maa_LIB_SRCS
   ${PROJECT_SOURCE_DIR}/src/i2c/i2cslave.cxx
   ${PROJECT_SOURCE_DIR}/src/i2c/smbus.c
   ${PROJECT_SOURCE_DIR}/src/gpio/gpio.c
+  ${PROJECT_SOURCE_DIR}/src/pwm/pwm.cxx
 )
 
 add_library (maa STATIC ${maa_LIB_SRCS})

src/pwm/pwm.cxx

@@ -0,0 +1,205 @@
+/*
+ * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
+ *
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+
+#include "pwm.h"
+
+using namespace maa;
+
+PWM::PWM(int chipin, int pinin)
+{
+    chipid = chipin;
+    pin = pinin;
+
+    FILE *export_f;
+    char buffer[64];
+    snprintf(buffer, 64, "/sys/class/pwm/pwmchip%d/export", chipid);
+
+    if((export_f = fopen(buffer, "w")) == NULL) {
+        fprintf(stderr, "Failed to open export for writing!\n");
+    } else {
+        fprintf(export_f, "%d", pin);
+        fclose(export_f);
+        setup_duty_fp();
+    }
+}
+
+void
+PWM::write(float percentage)
+{
+    write_duty(percentage*get_period());
+}
+
+float
+PWM::read()
+{
+    float output = get_duty() / (float) get_period();
+    return output;
+}
+
+void
+PWM::period(float seconds)
+{
+    period_ms(seconds*1000);
+}
+
+void
+PWM::period_ms(int ms)
+{
+    period_us(ms*1000);
+}
+
+void
+PWM::period_us(int us)
+{
+    write_period(us*1000);
+}
+
+void
+PWM::pulsewidth(float seconds)
+{
+    pulsewidth_ms(seconds*1000);
+}
+
+void
+PWM::pulsewidth_ms(int ms)
+{
+    pulsewidth_us(ms*1000);
+}
+
+void
+PWM::pulsewidth_us(int us)
+{
+    write_duty(us*1000);
+}
+
+void
+PWM::enable(int enable)
+{
+    int status;
+    if(enable != 0) {
+        status = 1;
+    } else {
+        status = enable;
+    }
+    FILE *enable_f;
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/enable", chipid, pin);
+
+    if((enable_f = fopen(bu, "w")) == NULL) {
+        fprintf(stderr, "Failed to open export for writing!\n");
+    } else {
+        fprintf(enable_f, "%d", status);
+        fclose(enable_f);
+    }
+    //Do Something
+}
+
+void
+PWM::close()
+{
+    enable(0);
+    FILE *unexport_f;
+    char buffer[64];
+    snprintf(buffer, 64, "/sys/class/pwm/pwmchip%d/unexport", chipid);
+
+    if((unexport_f = fopen(buffer, "w")) == NULL) {
+        fprintf(stderr, "Failed to open unexport for writing!\n");
+    } else {
+        fprintf(unexport_f, "%d", pin);
+        fclose(unexport_f);
+    }
+}
+
+void
+PWM::write_period(int period)
+{
+    FILE *period_f;
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/period", chipid, pin);
+
+    if((period_f = fopen(bu, "r+b")) == NULL) {
+        fprintf(stderr, "Failed to open period for writing!\n");
+    } else {
+        fprintf(period_f, "%d", period);
+        fclose(period_f);
+    }
+}
+
+void
+PWM::write_duty(int duty)
+{
+    if(duty_fp == NULL) {
+        setup_duty_fp();
+    }
+    fprintf(duty_fp, "%d", duty);
+    rewind(duty_fp);
+    fflush(duty_fp);
+}
+
+int
+PWM::setup_duty_fp()
+{
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/duty_cycle", chipid, pin);
+
+    if((duty_fp = fopen(bu, "r+b")) == NULL) {
+        return 1;
+    } else {
+        return 0;
+    }
+    return 1;
+}
+
+int
+PWM::get_period()
+{
+    FILE *period_f;
+    char bu[64];
+    char output[16];
+
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/period", chipid, pin);
+    if((period_f = fopen(bu, "rb")) == NULL) {
+        fprintf(stderr, "Failed to open period for reading!\n");
+        return 0;
+    } else {
+        fgets(output, 16, period_f);
+        fclose(period_f);
+        return atoi(output);
+    }
+}
+
+int
+PWM::get_duty()
+{
+    if(duty_fp == NULL) {
+        setup_duty_fp();
+    }
+    char output[16];
+    fgets(output, 16, duty_fp);
+    fseek(duty_fp, SEEK_SET, 0);
+    return atoi(output);
+}