Temperature versus ADC value

The example temperature table below shows temperature versus thermistor ADC value (hex and dec) with gain=1, and ADC mv for a sample thermistor. For full thermistor characteristics of the sample device search for Murata part NCP18XH103J03RB. The table assumes the nominal Vref of 3300mV.

The conversion to mV uses the formula

adc_mV = (Vref * adc_value)/adc_max_value

This table is accurate within a few degrees celsius.

Note : Adjust as necessary if Vref is not equal to 3300mV. Different thermistors may have a different correspondence between voltage and temperature. To create an accurate table for your particular thermistor you can calibrate with an accurate thermometer.

ADC value
hex
ADC value
dec
ADC mv Temp (deg. C) Temp (deg. F)
0xBB2 2994 2413 0 32.0
0xB8F 2960 2385 1 33.8
0xB6C 2925 2357 2 35.6
0xB48 2889 2328 3 37.4
0xB24 2853 2299 4 39.2
0xAFF 2816 2269 5 41.0
0xADB 2780 2240 6 42.8
0xAB6 2742 2210 7 44.6
0xA8F 2704 2179 8 46.4
0xA6A 2667 2149 9 48.2
0xA44 2628 2118 10 50.0
0xA1D 2590 2087 11 51.8
0x9F7 2551 2056 12 53.6
0x9D0 2513 2025 13 55.4
0x9AA 2474 1994 14 57.2
0x983 2436 1963 15 59.0
0x95C 2396 1931 16 60.8
0x935 2358 1900 17 62.6
0x90E 2318 1868 18 64.4
0x8E7 2280 1837 19 66.2
0x8BF 2240 1805 20 68.0
0x899 2201 1774 21 69.8
0x872 2163 1743 22 71.6
0x84C 2124 1712 23 73.4
0x825 2086 1681 24 75.2
0x7FF 2048 1650 25 77.0
0x7D9 2009 1619 26 78.8
0x7B3 1972 1589 27 80.6
0x78D 1933 1558 28 82.4
0x768 1896 1528 29 84.2
0x742 1859 1498 30 86.0
0x71E 1823 1469 31 87.8
0x6F9 1786 1439 32 89.6
0x6D5 1750 1410 33 91.4
0x6B1 1714 1381 34 93.2
0x68E 1679 1353 35 95.0
0x66C 1644 1325 36 96.8
0x649 1609 1297 37 98.6
0x627 1576 1270 38 100.4
0x606 1542 1243 39 102.2
0x5E4 1509 1216 40 104.0
0x5C3 1475 1189 41 105.8
0x5A3 1443 1163 42 107.6
0x584 1412 1138 43 109.4
0x565 1381 1113 44 111.2
0x546 1350 1088 45 113.0

A LUT file is a CSV file with the following format:

<Raw ADC Value (0-4095)>,<Floating point number>\r\n

Values are in decimal format.

A LUT file corresponding to the above table of characteristics has the following content:

0,125
1350,45
1381,44
1412,43
1443,42
1475,41
1509,40
1542,39
1576,38
1609,37
1644,36
1679,35
1714,34
1750,33
1786,32
1823,31
1859,30
1896,29
1933,28
1972,27
2009,26
2048,25
2086,24
2124,23
2163,22
2201,21
2240,20
2280,19
2318,18
2358,17
2396,16
2436,15
2474,14
2513,13
2551,12
2590,11
2628,10
2667,9
2704,8
2742,7
2780,6
2816,5
2853,4
2889,3
2925,2
2960,1
2994,0
4095,-125