5 ms·
Do you really need an SHT7x? The SHT21 has a datasheet accuracy of ±2% RH and ±0.3C compared to the SHT75 which has ±1.8% RH and ±0.3C. The repeatability of bot
by joshvm 10y ago
Do you really need an SHT7x? The SHT21 has a datasheet accuracy of ±2% RH and ±0.3C compared to the SHT75 which has ±1.8% RH and ±0.3C. The repeatability of both units is the same (±0.1%RH, ±0.1C. The '21 also consumes about 5 times less power in sleep mode and 3 times less in measurement mode.
You can pick up an SHT21 for about $3 (breakout included) and Sensirion sell clip on IP-rated membrane covers for outdoor applications - you just need to build it into your housing and provide an o-ring.
http://uk.rs-online.com/web/p/temperature-sensor-accessories/8854704/?origin=PSF_421367|acc http://uk.rs-online.com/web/p/temperature-sensor-accessories...
- emilburzo 10y ago> Do you really need an SHT7x? AFAIK the only difference between the SHT21 and SHT71 is the "packaging", they both use the same circuitry. So SHT21 == SHT71 and SHT25 == SHT75. > You can pick up an SHT21 for about $3 (breakout included) [...] Any links? I've had a lot of trouble finding something with an "Arduino" friendly breakout in that price range.
- joshvm 10y agoAlways eBay for this kind of thing http://www.ebay.co.uk/itm/Digital-SHT21-Humidity-And-Temperature-Sensor-Module-Replace-SHT11-SHT15-UK-CF-/272041588659?hash=item3f56f137b3:g:SSgAAOSwcUBYLps5 http://www.ebay.co.uk/itm/Digital-SHT21-Humidity-And-Tempera... You can even get a knockoff Sparkfun board (well it's open source, so not exactly knockoff): http://www.ebay.com/itm/Breakout-HTU21D-Temperature-and-Humidity-Sensor-Module-Temperature-Sensor/162242594396 http://www.ebay.com/itm/Breakout-HTU21D-Temperature-and-Humi... I'd go for the first one though, it looks like it has a membrane cover and does all the level conversion for you (it's only 3V3 tolerant). For some reason the SHT7x is an order of magnitude more expensive, no idea why.