extras/new_pwm: multi-channel soft PWM with example

.gitmodules

@@ -34,3 +34,6 @@
 [submodule "extras/libesphttpd/libesphttpd/lib/heatshrink"]
 	path = extras/libesphttpd/libesphttpd/lib/heatshrink
 	url = https://github.com/atomicobject/heatshrink
+[submodule "extras/new_pwm"]
+	path = extras/new_pwm
+	url = https://github.com/nochkin/new_pwm

examples/new_pwm/Makefile

@@ -0,0 +1,4 @@
+# Simple makefile for simple example
+PROGRAM = new_pwm
+EXTRA_COMPONENTS = extras/new_pwm
+include ../../common.mk

examples/new_pwm/new_pwm.c

@@ -0,0 +1,55 @@
+/* Very basic example to test the pwm library
+ * Hook up an LED to pin14 and you should see the intensity change
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2015 Javier Cardona (https://github.com/jcard0na)
+ * BSD Licensed as described in the file LICENSE
+ */
+#include "espressif/esp_common.h"
+#include "esp/uart.h"
+#include "FreeRTOS.h"
+#include "task.h"
+#include "new_pwm.h"
+
+#define PWM_CHANNELS 3
+const uint32_t period = 5000; // * 200ns ^= 1 kHz
+
+// PWM setup
+uint32_t io_info[PWM_CHANNELS][3] = {
+    {0, 0, 12},
+    {0, 0, 13},
+    {0, 0, 15},
+};
+
+// Initial duty: all off
+uint32_t pwm_duty_init[PWM_CHANNELS] = {0};
+
+void pwm_task(void *pvParameters)
+{
+    uint32_t counts[PWM_CHANNELS] = {0, 1000, 3000};
+    while(1) {
+        vTaskDelay(10);
+        for (uint8_t ii=0; ii<PWM_CHANNELS; ii++) {
+            pwm_set_duty(counts[ii], ii);
+            counts[ii] += period/32;
+            if (counts[ii] > period)
+                counts[ii] = 0;
+        }
+        pwm_start();
+    }
+}
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+
+    printf("pwm_init()\n");
+    pwm_init(period, pwm_duty_init, PWM_CHANNELS, io_info);
+
+    printf("pwm_start()\n");
+    pwm_start();
+
+    xTaskCreate(pwm_task, "new_pwm", 256, NULL, 2, NULL);
+}

extras/new_pwm

@@ -0,0 +1 @@
+Subproject commit 8b8fc35f5fa6c6209e9d77dc539cf34f0f151c30