Temperature & Humidity Sensor Evaluation and Testing
| Metric |
HTU21D |
Si72021 |
DHT22 |
DHT22 vs HTU21D Difference |
BME280 |
| Cost in 1k off |
£1.42 (July16) |
£2.15 |
£4.57 (July16) |
3.2 times cheaper (£3.15 less!) |
£3.07 |
| Vcc |
2.1v - 3.6V |
1.9V - 3.6V |
3.3-6V |
|
1.71 V - 3.6V |
| Humidity accuracy |
±2% RH |
±2% RH |
±2%RH |
n/a |
±3%RH |
| Humidity Range |
0-100% RH |
0-100% RH |
0-100% RH |
n/a |
0-100% RH |
| Temperature accuracy |
±0.3°C |
±0.4°C |
±0.5°C |
40% more accurate |
±0.5 - ±1.0 |
| Temperature Range |
-40°C +125°C |
-40°C +125°C |
-40°C +80°C |
56% more accurate |
-40°C +80°C |
| Sleep Current |
0.02uA |
0.06uA |
15uA |
750 times less power |
0.1uA - 0.3uA |
| Measurement Current |
0.045mA |
0.09 mA |
0.5mA |
11 times less power |
0.714mA - 0.350mA |
| Measurement time |
0.01s - 0.0026s |
0.01s - 0.0026s |
2s |
200 times faster |
0.013s |
| Energy consumed per sample |
1.5uJ |
2.97uJ |
3300uK |
2000 times less power |
|
| Time sampling per day* |
14.4s |
|
2800s |
|
|
| Time sleeping per day* |
86386s |
|
83600s |
|
|
| Energy consumed per day* |
2.36mW [1] |
|
2836mW [2] |
1201 times less energy per day! |
|
energy consumed (joule, J) = potential difference (volt, V) × charge (coulomb, C)
charge (coulomb, C) = current (ampere, A) × time (second, s)
energy consumed (joule, J) = potential difference (volt, V) × current (ampere, A) × time (second, s)
Energy consumed per day*
- HTU21D: (14.4s * 0.045mA) + (86386 * 0.00002mA) = 0.63mW + 1.73mW = 2.36mW [1]
- DHT22: (2800s * 0.55mA) + (86386 * 0.015mA) = 1540mW + 1295.8mW = 2836mW [2]
*Assuming 1 sample per min and sleeping in between samples, 1440 min per day = 86400s per day
Adafruit HTU21D Library
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