zeus 3110
/
MH-Z19_Test
CO2 Sensor MH-Z19 Class (uses interrupt input as PWM input)
Diff: MH_Z19.cpp
- Revision:
- 0:3c154d34f47e
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MH_Z19.cpp Thu Aug 11 00:41:23 2016 +0000 @@ -0,0 +1,45 @@ +/* mbed MH-Z19 Library + * Copyright (c) 2016, zeus3110 + * + * 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 "MH_Z19.h" + +MH_Z19::MH_Z19(PinName p) : Port(p) { + Port.rise(this, &MH_Z19::rise); + Port.fall(this, &MH_Z19::fall); + OnWidth=2; + T.start(); +} + +int MH_Z19::ReadCO2PPM() { + + return ((CO2_MAX_PPM)*(OnWidth-2)/(PWM_CYCLE_MS-4)); + +} + + +void MH_Z19::rise() { + T.reset(); +} + +void MH_Z19::fall() { + OnWidth=T.read_ms(); +}