fhksc.cpp

00001 /* Copyright (c) 2017 Philippe Kalaf, MIT License
00002  *
00003  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
00004  * and associated documentation files (the "Software"), to deal in the Software without restriction, 
00005  * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
00006  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
00007  * furnished to do so, subject to the following conditions:
00008  *
00009  * The above copyright notice and this permission notice shall be included in all copies or 
00010  * substantial portions of the Software.
00011  *
00012  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
00013  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
00014  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
00015  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
00016  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017  */
00018 
00019 /* Digmesa FHKSC flowmeter driver */
00020 #include "fhksc.h"
00021 
00022 FHKSC::FHKSC(PinName pin) : _interrupt(pin) {        // create the InterruptIn on the pin specified to FHKSC
00023         _interrupt.mode(PullDown); // an internal pull up is used, otherwise disable here
00024         _interrupt.rise(callback(this, &FHKSC::increment)); // attach increment function of this counter instance  
00025         _flow_rate_timer.start(); 
00026         _time_last_increment_us = 0;
00027 }
00028 
00029 void FHKSC::increment()
00030 {
00031     int time_us = _flow_rate_timer.read_us();
00032     // Every 1925 pulses is 1L
00033     // Each pulse is 1000000/1925 = 520 ul or 0.52 ml
00034     _flow_ul += 520;
00035     _interval_between_increments_us = time_us - _time_last_increment_us;
00036     _time_last_increment_us = time_us;
00037 }
00038 
00039 // return in ml
00040 float FHKSC::get_volume()
00041 {
00042     return float(_flow_ul)/1000;
00043 }
00044 
00045 uint32_t FHKSC::get_volume_ul()
00046 {
00047     return _flow_ul;
00048 }
00049 
00050 void FHKSC::reset_count()
00051 {
00052     _flow_ul = 0;
00053     // reset timer since it can only run for 30 mins
00054     _flow_rate_timer.reset();
00055     _time_last_increment_us = 0;
00056 }
00057 
00058 // flow rate in ml per second
00059 float FHKSC::get_flow_rate()
00060 {
00061     int time_us = _flow_rate_timer.read_us();
00062     // if we got no incremenet in 2 seconds, flowrate is 0
00063     if (time_us - _time_last_increment_us > 2000000)
00064     return 0;
00065 
00066     if (_interval_between_increments_us)
00067     return float(0.52 / (float(_interval_between_increments_us)/1000000));
00068     else
00069     return 0;
00070 }