April 15, 2020   |   by admin

AM (wired DHT22) temperature-humidity sensor . DHT11 datasheet (https ://)(in chinese, so see the DHT22 datasheet too!). AM digital temperature and humidity module is a digital output signal containing a calibrated temperature and humidity combined sensor. It uses a. AM Datasheet PDF Download – Digital temperature and humidity sensor, AM data sheet.

Author: Moktilar Grohn
Country: Turkey
Language: English (Spanish)
Genre: Automotive
Published (Last): 7 June 2012
Pages: 244
PDF File Size: 19.64 Mb
ePub File Size: 11.94 Mb
ISBN: 683-4-57071-414-1
Downloads: 58158
Price: Free* [*Free Regsitration Required]
Uploader: Mezilmaran

It was only by reading the internal serial numbers I was able to ascertain that. Temperature and Humidity both are bit Accuracy: This means that with due regard to the errors already determined, hysteresis is not a signficant extra effect.

Deviations from the known reference value as humidity is systematically cycled from high to am230 and back to high.

The AM is effectively the latest version of the AM with the addition of an option to communicate over I2C interface. Similarly the Sensirion SHT21 not included here also has a near identical specification and interface. It worked again immediately once the humidity dropped.

My conclusion was that is has virtually no impact at all. Finally, if a sensor is to be used to measure humidity under a range of varying temperatures a full bivariate calibration is required.

The AM appears to be the same but in a much smaller physical package and narrower pin pitch. When running at the default full speed my device returned temperatures 0. The sensor itself is the small square component in the top right of each board.

DHT22 Sensor Pinout, Specs, Equivalents, Circuit & Datasheet

The hysteresis envelope was nice datxsheet tight. If the device caps output at 0— it makes it difficult to apply your own re-calibration near those limits.


Hystersis was almost undetectable. The reference calibration sources are the same as before, eleven saturated solutions and distilled water. Though primarily interested in humidity, I present a brief comparison of the temperature measurements.

Where the slopes of dataaheet measurements and reference data differ e. Hysteresis is the tendancy of a physical system’s state to depend on its past state. For details of how the experiment works, please refer to the previous write-ups.

Only for the BME is there a convincing detection of the thermometer being slightly humidity sensitive.

(PDF) AM2302 Datasheet download

The one difference I have found and possibly the only way to be sure which device you have is in the devices’ unique serial numbers for which each manufacturer uses a slightly different format, detailed in their respective datasheets. Though an interesting addition and I will write about it elsewhere, for the present report I present only the temperature and humidity data.

It is a nice compact and apparently robust unit, especially with the optional cover screen. This run confirms my previous experiments with this device. In any case, they fulfill the manufacturer’s specified 1. The others all continue uneffected but values were only logged daatsheet this sensor when they were sensible.

Left panel shows data directly from the sensors. Notes on particular sensors: Blue shows low readings and red are high.

This, the Si and the SHT71 showed comparable errors overall. That is not to say they will all perform identically. The module is slightly costly than the DHT11, but it has a higher measuring range and slightly better accuracy.


My current supposition is that it uses a resistive film rather than a capactive film. Figure 11 shows an apparent scatter but replotting temperature errors as a function of humidity Figure 12 shows a tight correlation with very little dispersion.

AM2302 Datasheet

A couple of sensors do show a strong effect. The difference is small 0. Though I designed and integrated the entire experiment, I must acknowledge the many open source projects, both software dxtasheet hardware, that I used. Two complete cycles of the loop from wet to dry and back to wet were performed.

AM Datasheet PDF –

It might be electrically identical. Over two dqtasheet, three of the original six devices have failed. The dark grey lines are the new hystersis test and create envelope inside which all the readings will fall. This data pin outputs the value of both temperature and humidity as serial data. Device E was selected as the best of the six I originally started with.

Currently I am attributing it to bad luck in my getting a couple of faulty devices rather than a systematic fault with this model. Front Page Kimberly Robert Hygrometers. The shaded grey region is the specified tolerance from the manufacturers’ datasheets.

Figure 3 shows the actual relative humidity values measured datssheet Figure 4 shows the deviations from a perfect calibration.