1 /*
2 * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
3 * Copyright (c) 2014 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 <iostream>
26 #include <unistd.h>
27 #include <stdlib.h>
28 #include <stdexcept>
29
30 #include "mlx90614.h"
31
32 using namespace upm;
33
MLX90614(int bus,int devAddr)34 MLX90614::MLX90614 (int bus, int devAddr) : m_i2Ctx(bus) {
35 m_name = "MLX90614";
36
37 m_i2cAddr = devAddr;
38 m_bus = bus;
39
40 mraa::Result ret = m_i2Ctx.address(m_i2cAddr);
41 if (ret != mraa::SUCCESS) {
42 throw std::invalid_argument(std::string(__FUNCTION__) +
43 ": address() failed");
44 }
45 }
46
47 float
readObjectTempF(void)48 MLX90614::readObjectTempF(void) {
49 return (readTemperature(MLX90614_TOBJ1) * 9 / 5) + 32;
50 }
51
52 float
readAmbientTempF(void)53 MLX90614::readAmbientTempF(void) {
54 return (readTemperature(MLX90614_TA) * 9 / 5) + 32;
55 }
56
57 float
readObjectTempC(void)58 MLX90614::readObjectTempC(void) {
59 return readTemperature(MLX90614_TOBJ1);
60 }
61
62 float
readAmbientTempC(void)63 MLX90614::readAmbientTempC(void) {
64 return readTemperature(MLX90614_TA);
65 }
66
67 /*
68 * **************
69 * private area
70 * **************
71 */
72 uint16_t
i2cReadReg_N(int reg,unsigned int len,uint8_t * buffer)73 MLX90614::i2cReadReg_N (int reg, unsigned int len, uint8_t * buffer) {
74 int readByte = 0;
75
76 m_i2Ctx.address(m_i2cAddr);
77 m_i2Ctx.writeByte(reg);
78
79 readByte = m_i2Ctx.read(buffer, len);
80 return readByte;
81 }
82
83 mraa::Result
i2cWriteReg_N(uint8_t reg,unsigned int len,uint8_t * buffer)84 MLX90614::i2cWriteReg_N (uint8_t reg, unsigned int len, uint8_t * buffer) {
85 mraa::Result error = mraa::SUCCESS;
86
87 error = m_i2Ctx.address(m_i2cAddr);
88 error = m_i2Ctx.write(buffer, len);
89
90 return error;
91 }
92
93 float
readTemperature(uint8_t address)94 MLX90614::readTemperature (uint8_t address) {
95 uint8_t buffer[3];
96 float temperature = 0;
97
98 /* Reading temperature from sensor.
99 Answer contained of 3 bytes (TEMP_LSB | TEMP_MSB | PEC)
100 */
101 if (i2cReadReg_N(address, 3, buffer) > 2) {
102 temperature = buffer[0];
103 temperature = buffer[1] << 8;
104
105 temperature *= .02;
106 temperature -= 273.15;
107 }
108
109 return temperature;
110 }
111