Gabriel Silva
/
mlx90615_lpc1768
program for temperature reading with mlx90615
Mlx90615.cpp@0:db513e91a2c9, 2020-07-15 (annotated)
- Committer:
- glsfacom
- Date:
- Wed Jul 15 18:20:00 2020 +0000
- Revision:
- 0:db513e91a2c9
- Child:
- 2:c4552b8c47c0
export to mbed studio;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
glsfacom | 0:db513e91a2c9 | 1 | #include "Mlx90615.h" |
glsfacom | 0:db513e91a2c9 | 2 | #include "smbus.h" |
glsfacom | 0:db513e91a2c9 | 3 | |
glsfacom | 0:db513e91a2c9 | 4 | I2C i2c(p28, p27);//I2C_SDA, I2C_SCL |
glsfacom | 0:db513e91a2c9 | 5 | void Mlx90615::wake() |
glsfacom | 0:db513e91a2c9 | 6 | { |
glsfacom | 0:db513e91a2c9 | 7 | /*SCL = 0; |
glsfacom | 0:db513e91a2c9 | 8 | wait_ms(50); |
glsfacom | 0:db513e91a2c9 | 9 | SCL = 1;*/ |
glsfacom | 0:db513e91a2c9 | 10 | MLX_VCC = 1; |
glsfacom | 0:db513e91a2c9 | 11 | wait_us(301*1000);//Waiting for valid data as datasheet says |
glsfacom | 0:db513e91a2c9 | 12 | } |
glsfacom | 0:db513e91a2c9 | 13 | |
glsfacom | 0:db513e91a2c9 | 14 | unsigned int Mlx90615::sleep(){ |
glsfacom | 0:db513e91a2c9 | 15 | MLX_VCC = 0; |
glsfacom | 0:db513e91a2c9 | 16 | return 1; |
glsfacom | 0:db513e91a2c9 | 17 | } |
glsfacom | 0:db513e91a2c9 | 18 | |
glsfacom | 0:db513e91a2c9 | 19 | unsigned int Mlx90615::read(unsigned char memory, unsigned char address){ |
glsfacom | 0:db513e91a2c9 | 20 | unsigned char crc, addr, status = 0; |
glsfacom | 0:db513e91a2c9 | 21 | unsigned int read = 0x0000; |
glsfacom | 0:db513e91a2c9 | 22 | |
glsfacom | 0:db513e91a2c9 | 23 | addr = memory + address; |
glsfacom | 0:db513e91a2c9 | 24 | |
glsfacom | 0:db513e91a2c9 | 25 | i2c.start(); |
glsfacom | 0:db513e91a2c9 | 26 | |
glsfacom | 0:db513e91a2c9 | 27 | smbus_send_address(0x5B, WRITE); |
glsfacom | 0:db513e91a2c9 | 28 | if(!i2c.ACK) return 0; |
glsfacom | 0:db513e91a2c9 | 29 | |
glsfacom | 0:db513e91a2c9 | 30 | smbus_send_byte(addr); |
glsfacom | 0:db513e91a2c9 | 31 | if(!i2c.ACK) return 0; |
glsfacom | 0:db513e91a2c9 | 32 | |
glsfacom | 0:db513e91a2c9 | 33 | i2c.start(); |
glsfacom | 0:db513e91a2c9 | 34 | |
glsfacom | 0:db513e91a2c9 | 35 | smbus_send_address(0x5B, READ); |
glsfacom | 0:db513e91a2c9 | 36 | if(!i2c.ACK) return 0; |
glsfacom | 0:db513e91a2c9 | 37 | |
glsfacom | 0:db513e91a2c9 | 38 | read = smbus_read_uint(&status, LITTLE_ENDIAN); |
glsfacom | 0:db513e91a2c9 | 39 | |
glsfacom | 0:db513e91a2c9 | 40 | crc = smbus_read_byte(&status); |
glsfacom | 0:db513e91a2c9 | 41 | |
glsfacom | 0:db513e91a2c9 | 42 | smbus_stop(); |
glsfacom | 0:db513e91a2c9 | 43 | |
glsfacom | 0:db513e91a2c9 | 44 | return read; |
glsfacom | 0:db513e91a2c9 | 45 | } |
glsfacom | 0:db513e91a2c9 | 46 | |
glsfacom | 0:db513e91a2c9 | 47 | unsigned int Mlx90615::read_temperature(){ |
glsfacom | 0:db513e91a2c9 | 48 | unsigned int temp = read(RAM, 0x07); |
glsfacom | 0:db513e91a2c9 | 49 | while(temp == 0) |
glsfacom | 0:db513e91a2c9 | 50 | { |
glsfacom | 0:db513e91a2c9 | 51 | wait_us(5000); |
glsfacom | 0:db513e91a2c9 | 52 | temp = read(RAM, 0x07); |
glsfacom | 0:db513e91a2c9 | 53 | } |
glsfacom | 0:db513e91a2c9 | 54 | return temp; |
glsfacom | 0:db513e91a2c9 | 55 | } |
glsfacom | 0:db513e91a2c9 | 56 | |
glsfacom | 0:db513e91a2c9 | 57 | /*float convert_to_celsius(unsigned int temperature){ |
glsfacom | 0:db513e91a2c9 | 58 | return temperature * 0.02 - 273.15; |
glsfacom | 0:db513e91a2c9 | 59 | }*/ |
glsfacom | 0:db513e91a2c9 | 60 | typedef unsigned char uint8_t; |
glsfacom | 0:db513e91a2c9 | 61 | |
glsfacom | 0:db513e91a2c9 | 62 | uint8_t gencrc(uint8_t *data, size_t len) |
glsfacom | 0:db513e91a2c9 | 63 | { |
glsfacom | 0:db513e91a2c9 | 64 | uint8_t crc = 0xff; |
glsfacom | 0:db513e91a2c9 | 65 | size_t i, j; |
glsfacom | 0:db513e91a2c9 | 66 | for (i = 0; i < len; i++) { |
glsfacom | 0:db513e91a2c9 | 67 | crc ^= data[i]; |
glsfacom | 0:db513e91a2c9 | 68 | for (j = 0; j < 8; j++) { |
glsfacom | 0:db513e91a2c9 | 69 | if ((crc & 0x80) != 0) |
glsfacom | 0:db513e91a2c9 | 70 | crc = (uint8_t)((crc << 1) ^ 0x31); |
glsfacom | 0:db513e91a2c9 | 71 | else |
glsfacom | 0:db513e91a2c9 | 72 | crc <<= 1; |
glsfacom | 0:db513e91a2c9 | 73 | } |
glsfacom | 0:db513e91a2c9 | 74 | } |
glsfacom | 0:db513e91a2c9 | 75 | return crc; |
glsfacom | 0:db513e91a2c9 | 76 | } |
glsfacom | 0:db513e91a2c9 | 77 | |
glsfacom | 0:db513e91a2c9 | 78 | void Mlx90615::write(unsigned char address, unsigned int value){ |
glsfacom | 0:db513e91a2c9 | 79 | unsigned char addr = EEPROM + address; |
glsfacom | 0:db513e91a2c9 | 80 | unsigned char bytes[4], crc, vh, vl; |
glsfacom | 0:db513e91a2c9 | 81 | vh = value >> 8; |
glsfacom | 0:db513e91a2c9 | 82 | vl = value; |
glsfacom | 0:db513e91a2c9 | 83 | bytes[0] = 0xB6; |
glsfacom | 0:db513e91a2c9 | 84 | bytes[1] = addr; |
glsfacom | 0:db513e91a2c9 | 85 | bytes[2] = vl; |
glsfacom | 0:db513e91a2c9 | 86 | bytes[3] = vh; |
glsfacom | 0:db513e91a2c9 | 87 | crc = gencrc(bytes, 4); |
glsfacom | 0:db513e91a2c9 | 88 | |
glsfacom | 0:db513e91a2c9 | 89 | i2c.start(); |
glsfacom | 0:db513e91a2c9 | 90 | |
glsfacom | 0:db513e91a2c9 | 91 | smbus_send_address(0x5B, WRITE); |
glsfacom | 0:db513e91a2c9 | 92 | |
glsfacom | 0:db513e91a2c9 | 93 | smbus_send_byte(addr); |
glsfacom | 0:db513e91a2c9 | 94 | |
glsfacom | 0:db513e91a2c9 | 95 | smbus_send_byte(vl); |
glsfacom | 0:db513e91a2c9 | 96 | |
glsfacom | 0:db513e91a2c9 | 97 | smbus_send_byte(vh); |
glsfacom | 0:db513e91a2c9 | 98 | |
glsfacom | 0:db513e91a2c9 | 99 | smbus_send_byte(crc); |
glsfacom | 0:db513e91a2c9 | 100 | |
glsfacom | 0:db513e91a2c9 | 101 | smbus_stop(); |
glsfacom | 0:db513e91a2c9 | 102 | } |
glsfacom | 0:db513e91a2c9 | 103 | |
glsfacom | 0:db513e91a2c9 | 104 | void Mlx90615::erase_eeprom_address(unsigned char address){ |
glsfacom | 0:db513e91a2c9 | 105 | write(address, 0x0000); |
glsfacom | 0:db513e91a2c9 | 106 | } |
glsfacom | 0:db513e91a2c9 | 107 | |
glsfacom | 0:db513e91a2c9 | 108 | void Mlx90615::set_emissivity(float e){ |
glsfacom | 0:db513e91a2c9 | 109 | unsigned int emissivity; |
glsfacom | 0:db513e91a2c9 | 110 | emissivity = 16384 * e; |
glsfacom | 0:db513e91a2c9 | 111 | erase_eeprom_address(0x03); |
glsfacom | 0:db513e91a2c9 | 112 | wait_us(5*1000); |
glsfacom | 0:db513e91a2c9 | 113 | write(0x03, emissivity); |
glsfacom | 0:db513e91a2c9 | 114 | } |