1 /*
2  * Author: Marc Graham <marc@m2ag.net>
3  * Copyright (c) 2015 Intel Corporation.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be
14  * included in all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  */
24 
25 #include "micsv89.h"
26 
27 using namespace upm;
28 
MICSV89(int bus,uint8_t address)29 MICSV89::MICSV89 (int bus, uint8_t address) {
30     m_name = "micsv89";
31     m_valid = false;
32     m_address = address;
33     i2c = new mraa::I2c(bus);
34     if(i2c->frequency(mraa::I2C_STD) != mraa::SUCCESS){
35       throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.frequency(I2C_STD) failed");
36       return;
37     }
38     tx_buf[0] = 0x09;
39     tx_buf[1] = 0x00;
40     tx_buf[2] = 0x00;
41 }
42 
update()43 void MICSV89::update() {
44     m_valid = false;
45     if(i2c->address(m_address) != mraa::SUCCESS){
46       throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.address() failed");
47       return;
48     }
49     if(i2c->write(tx_buf, 3) != mraa::SUCCESS){
50       throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.write() failed");
51       return;
52     }
53     sleep(1); //Give the device time to make the measurement.
54     if(i2c->address(m_address) != mraa::SUCCESS){
55       throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.address() failed");
56       return;
57     }
58     if(i2c->read(rx_buf, 6) != 6){
59       throw std::invalid_argument(std::string(__FUNCTION__) + ": I2c.read() failed");
60       return;
61     }
62     m_valid = true;
63 }
64 
co2equ()65 float MICSV89::co2equ() {
66     return ((rx_buf[0] - 13) * (1600/229) + 400);
67 }
68 
vocshort()69 int MICSV89::vocshort() {
70     return rx_buf[1];
71 }
72 
tvoc()73 float MICSV89::tvoc() {
74     return rx_buf[2] * (1000/229);
75 }
76 
resistor()77 float MICSV89::resistor() {
78     return 10 * (rx_buf[3] + (256 * rx_buf[4]) + (65536 * rx_buf[5]));
79 }
80 
~MICSV89()81 MICSV89::~MICSV89() {
82     delete i2c;
83 }
84