Data Sheet

MLX90640 32x24 IR array
Datasheet
Page 13 of 60
REVISION 11 – 3 AUGUST 2018
10.5.
10.5.10.5.
10.5. Measurement flow
Measurement flowMeasurement flow
Measurement flow
Following measurement flow is recommended:
POR
Wait 80ms + delay determined by the refresh rate
Absolute temp measurement?
Yes
0.5 Hz 4 sec
1 Hz 2 sec
2 Hz 1 sec
….
64 Hz 0.03125 sec
No
Wait app 4 min
Read meas data
Clear bit “New data available in RAM” - Bit3 in 0x8000
Wait time determined by RR – 20%
Measurement Flow
Is “New data available in RAM” set
No
Sub frame “0”
Yes
Read meas data
Clear bit “New data available in RAM” - Bit3 in 0x8000
Calculate the temperature of the sub frame “1”
Sub frame “1”
Calculate the temperature of the sub frame “0”
Wait time determined by RR – 20%
Is “New data available in RAM” set
No
Yes
Image processing
decision making
Step mode ?
Set Start Of Measurement – Bit5 in 0x8000
Yes
No
Step mode ?
Set Start Of Measurement – Bit5 in 0x8000
Yes
No
Image processing
decision making
Extract calibration data from EEPROM and store in RAMJust once after POR
Figure 7 Recommended measurement flow