/* * Author: Jon Trulson * Copyright (c) 2017 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 #include #include #include "wfs.h" // interrupt handler static void wfs_flow_isr(void *ctx) { assert(ctx != NULL); wfs_context dev = (wfs_context)ctx; dev->flowCounter++; } wfs_context wfs_init(int pin) { // make sure MRAA is initialized int mraa_rv; if ((mraa_rv = mraa_init()) != MRAA_SUCCESS) { printf("%s: mraa_init() failed (%d).\n", __FUNCTION__, mraa_rv); return NULL; } wfs_context dev = (wfs_context)malloc(sizeof(struct _wfs_context)); if (!dev) return NULL; // zero out context memset((void *)dev, 0, sizeof(struct _wfs_context)); if ( !(dev->gpio = mraa_gpio_init(pin)) ) { printf("%s: mraa_gpio_init() failed.\n", __FUNCTION__); wfs_close(dev); return NULL; } mraa_gpio_dir(dev->gpio, MRAA_GPIO_IN); wfs_init_clock(dev); return dev; } void wfs_close(wfs_context dev) { assert(dev != NULL); if (dev->isrInstalled) wfs_stop_flow_counter(dev); if (dev->gpio) mraa_gpio_close(dev->gpio); free(dev); } void wfs_init_clock(const wfs_context dev) { assert(dev != NULL); upm_clock_init(&dev->clock); } uint32_t wfs_get_millis(const wfs_context dev) { assert(dev != NULL); return upm_elapsed_ms(&dev->clock); } void wfs_clear_flow_counter(const wfs_context dev) { assert(dev != NULL); dev->flowCounter = 0; } upm_result_t wfs_start_flow_counter(const wfs_context dev) { assert(dev != NULL); wfs_init_clock(dev); // install our interrupt handler if (mraa_gpio_isr(dev->gpio, MRAA_GPIO_EDGE_RISING, &wfs_flow_isr, dev)) { printf("%s: mraa_gpio_isr() failed.\n", __FUNCTION__); return UPM_ERROR_OPERATION_FAILED; } dev->isrInstalled = true; return UPM_SUCCESS; } void wfs_stop_flow_counter(const wfs_context dev) { assert(dev != NULL); // remove the interrupt handler mraa_gpio_isr_exit(dev->gpio); dev->isrInstalled = false; } uint32_t wfs_flow_counter(const wfs_context dev) { assert(dev != NULL); return dev->flowCounter; } float wfs_flow_rate(const wfs_context dev) { assert(dev != NULL); uint32_t millis = wfs_get_millis(dev); uint32_t flow = wfs_flow_counter(dev); // 7.5 comes from the seeedstudio page, see the confusing datasheet :) return ((float)flow * 7.5) / ( ((float)millis / 1000.0) * 60.0); }