void setup()
{
Serial.begin(115200);
Serial.println("MLX90620 Example");
i2c_init(); //Init the I2C pins
PORTC = (1 << PORTC4) | (1 << PORTC5); //Enable pull-ups
delay(5); //Init procedure calls for a 5ms delay after power-on
read_EEPROM_MLX90620(); //Read the entire EEPROM
setConfiguration(refreshRate); //Configure the MLX sensor with the user's choice of refresh rate
calculate_TA(); //Calculate the current Tambient
}
static void mlx90620_read_to(float *t)
{
float v_ir_comp;
float v_ir_off_comp;
float v_ir_tgc_comp;
int16_t cpix;
uint8_t cmd_buf[4];
int16_t ir_data[64];
// static int count=0;
// if (count++ %16 ==0) {
float Ta = calculate_TA();
// (T+273.15f)^4
float Ta4 = (Ta + 273.15f) * (Ta + 273.15f) * (Ta + 273.15f) * (Ta + 273.15f);
// }
// Read IR data
memcpy(cmd_buf, (uint8_t [4]){MLX_READ_REG, 0x00, 0x01, 0x40}, sizeof(cmd_buf)); //read 64*2 bytes
soft_i2c_write_bytes(MLX_SLAVE_ADDR, cmd_buf, sizeof(cmd_buf), false);
soft_i2c_read_bytes(MLX_SLAVE_ADDR, (uint8_t*)ir_data, 128, true);
// Read compensation data
memcpy(cmd_buf, (uint8_t [4]){MLX_READ_REG, 0x91, 0x00, 0x01}, sizeof(cmd_buf));
soft_i2c_write_bytes(MLX_SLAVE_ADDR, cmd_buf, sizeof(cmd_buf), false);
soft_i2c_read_bytes(MLX_SLAVE_ADDR, (uint8_t*)&cpix, 2, true);
//Calculate the offset compensation for the one compensation pixel
//This is a constant in the TO calculation, so calculate it here.
float v_cp_off_comp = (float)cpix - (a_cp + (b_cp/(2<<(b_i_scale-1))) * (Ta - 25));
for (int i=0; i<64; i++) {
//#1: Calculate Offset Compensation
v_ir_off_comp = ir_data[i] - (a_ij[i] + (float)(b_ij[i]/(2<<(b_i_scale-1))) * (Ta - 25));
//#2: Calculate Thermal Gradien Compensation (TGC)
v_ir_tgc_comp = v_ir_off_comp - ( ((float)tgc/32) * v_cp_off_comp);
//#3: Calculate Emissivity Compensation
v_ir_comp = v_ir_tgc_comp / emissivity;
t[i] = fast_sqrtf(fast_sqrtf(v_ir_comp/alpha_ij[i] + Ta4)) - 273.15f;
}
}
void loop()
{
if(loopCount++ == 16) //Tambient changes more slowly than the pixel readings. Update TA only every 16 loops.
{
calculate_TA(); //Calculate the new Tambient
if(checkConfig_MLX90620()) //Every 16 readings check that the POR flag is not set
{
Serial.println("POR Detected!");
setConfiguration(refreshRate); //Re-write the configuration bytes to the MLX
}
loopCount = 0; //Reset count
}
readIR_MLX90620(); //Get the 64 bytes of raw pixel data into the irData array
calculate_TO(); //Run all the large calculations to get the temperature data for each pixel
prettyPrintTemperatures(); //Print the array in a 4 x 16 pattern
//rawPrintTemperatures(); //Print the entire array so it can more easily be read by Processing app
}