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Example program showing how to get the temperature readings from an MLX90614 infrared temperature sensor using an mbed.
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| #pragma once | |
| namespace gy906 { | |
| //const int default_addr = 0x5a; | |
| const int default_addr = 0x00; | |
| namespace opcode { | |
| const int eeprom_access = 0x20; | |
| const int ram_access = 0x00; | |
| const int read_flags = 0xf0; | |
| const int sleep = 0xff; | |
| const int read_mask = 0x80; | |
| const int write_mask = 0x00; | |
| } | |
| namespace eeprom { | |
| const int T0_max = 0x00; | |
| const int T0_min = 0x01; | |
| const int PWMCTRL = 0x02; | |
| const int Ta_range = 0x03; | |
| const int EC_coef = 0x04; | |
| const int config_reg1 = 0x05; | |
| const int SMBus_addr = 0x0e; | |
| const int id1 = 0x1c; | |
| const int id2 = 0x1d; | |
| const int id3 = 0x1e; | |
| const int id4 = 0x1f; | |
| } | |
| namespace ram { | |
| const int ir1 = 0x04; | |
| const int ir2 = 0x05; | |
| const int T_ambient = 0x06; | |
| const int T_obj1 = 0x07; | |
| const int T_obj2 = 0x08; | |
| } | |
| } |
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| /* | |
| * Example program showing how to get the temperature readings from | |
| * an MLX90614 infrared temperature sensor using an mbed. | |
| * http://www.haoyuelectronics.com/Attachment/GY-906/MLX90614.pdf | |
| * | |
| * Jonathan Jones | |
| */ | |
| #include "mbed.h" | |
| #include "gy-906.h" | |
| using namespace gy906; | |
| I2C i2c(p9, p10); | |
| const uint8_t addr = default_addr; | |
| // kelvin to fahrenheit | |
| float k2f(float raw_kelvin) | |
| { | |
| return (raw_kelvin - 273.15) * 1.8 + 32; | |
| } | |
| // read and return one of the temperature regs | |
| float get_temp(uint8_t reg) { | |
| char cmd[3] = { 0 }; | |
| // read the temperature data (kelvin) | |
| cmd[0] = opcode::ram_access | reg; | |
| i2c.write(addr,cmd,1,true); i2c.read(addr,cmd,3); | |
| // convert to meaningful units, still in kelvin - just normalized | |
| return 0.02 * static_cast<float>((cmd[1]<<8)|cmd[0]); | |
| } | |
| int main() { | |
| uint8_t reg_addrs[] = { ram::T_ambient, ram::T_obj1 }; | |
| float tt = 0.0; | |
| // clear terminal & hide cursor | |
| printf("\033[r\033[2J\033[?25l"); fflush(stdout); | |
| while (true) { | |
| for (size_t i = 0; i < sizeof(reg_addrs); ++i) { | |
| tt = get_temp(reg_addrs[i]); | |
| printf("\r\033[KT%u:\t%.2f°F\r\n", i, k2f(tt)); | |
| fflush(stdout); | |
| } | |
| wait(0.1); | |
| printf("\033[%uA", sizeof(reg_addrs)); fflush(stdout); | |
| } | |
| } |
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