DHT11 Sensor
|
View:
New views
7 Messages
—
Rating Filter:
Alert me
|
 |
DHT11 Sensor
by MickSulley
::
Rate this Message:
Does anyone have any experience of the DHT11 temp/humidity sensor? I
just found it while looking for something else, it sounds very cheap for a combined temp and humidity sensor, £2.75 on eBay, but I am not convinced that it is compatible with 1-wire and owfs as I don't see any address in the description. There is a description here http://www.ladyada.net/learn/sensors/dht.html but my limited technical knowledge can't determine if it would work or what else would need to be done to get it to work. Thanks Mick ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by Eloy Paris
::
Rate this Message:
Hi Mick,
On 02/03/2012 04:23 PM, Mick Sulley wrote: > Does anyone have any experience of the DHT11 temp/humidity sensor? I > just found it while looking for something else, it sounds very cheap for > a combined temp and humidity sensor, £2.75 on eBay, but I am not > convinced that it is compatible with 1-wire and owfs as I don't see any > address in the description. > > There is a description here > http://www.ladyada.net/learn/sensors/dht.html but my limited technical > knowledge can't determine if it would work or what else would need to be > done to get it to work. I have experience with the DHT11's older brother, the RHT03. Both work very similarly and as far as I know the only difference is price (one has better accuracy and temperature and humidity range than the other). Without a doubt, these guys do not speak Maxim/Dallas 1-Wire protocol; it's its own thing. I am working on a microcontroller-based 1-Wire slave that uses an RHT03 as the humidity/temperature sensor and it works great. I have not deployed one of these yet so I am not sure how well the RHT03 will work in a production environment (like in my garage, basement, or outside) but at least in inside tests it is looking pretty good. I'd say these cheap sensors are a great option, but you definitely need to hook them up to a microcontroller (it's not hard at all but it is not typical PC development). Cheers, Eloy Paris.- P.S. There are Arduino libraries to talk to these sensors so using an Arduino is an option if hardware development is not desired. The problem would be getting the Arduino to behave like a Dallas 1-Wire slave, though there is at least one GPL implementation out there that someone could use as a starting point. ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by MickSulley
::
Rate this Message:
Thanks for that Eloy, I suspected that would be the case. I would be
interested to hear your experiences with it when it goes into your 'production' environment. I am planning to measure and control humidity in our pool area, but have several things above that on the priority list, so it won't be for a while yet. Cheers Mick On 03/02/12 21:34, Eloy Paris wrote: > Hi Mick, > > On 02/03/2012 04:23 PM, Mick Sulley wrote: > >> Does anyone have any experience of the DHT11 temp/humidity sensor? I >> just found it while looking for something else, it sounds very cheap for >> a combined temp and humidity sensor, £2.75 on eBay, but I am not >> convinced that it is compatible with 1-wire and owfs as I don't see any >> address in the description. >> >> There is a description here >> http://www.ladyada.net/learn/sensors/dht.html but my limited technical >> knowledge can't determine if it would work or what else would need to be >> done to get it to work. > I have experience with the DHT11's older brother, the RHT03. Both work > very similarly and as far as I know the only difference is price (one > has better accuracy and temperature and humidity range than the other). > > Without a doubt, these guys do not speak Maxim/Dallas 1-Wire protocol; > it's its own thing. > > I am working on a microcontroller-based 1-Wire slave that uses an RHT03 > as the humidity/temperature sensor and it works great. I have not > deployed one of these yet so I am not sure how well the RHT03 will work > in a production environment (like in my garage, basement, or outside) > but at least in inside tests it is looking pretty good. > > I'd say these cheap sensors are a great option, but you definitely need > to hook them up to a microcontroller (it's not hard at all but it is not > typical PC development). > > Cheers, > > Eloy Paris.- > > P.S. There are Arduino libraries to talk to these sensors so using an > Arduino is an option if hardware development is not desired. The problem > would be getting the Arduino to behave like a Dallas 1-Wire slave, > though there is at least one GPL implementation out there that someone > could use as a starting point. > > ------------------------------------------------------------------------------ > Try before you buy = See our experts in action! > The most comprehensive online learning library for Microsoft developers > is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, > Metro Style Apps, more. Free future releases when you subscribe now! > http://p.sf.net/sfu/learndevnow-dev2 > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@... > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by Patryk-6
::
Rate this Message:
Dnia 03-02-2012 o 22:47:26 Mick Sulley <mick@...> napisał(a):
I was also thinking about this sensor it has a digital output which can be connected to uC. There is also DHT22 which has greater range. From what I read these are based on a capacitor which capacitance is based on humidity. I wonder how long do they live. I've read that some types of sensor wear out after about 5 years. > Thanks for that Eloy, I suspected that would be the case. I would be > interested to hear your experiences with it when it goes into your > 'production' environment. I'm also looking forward to see it. -- p4trykx ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by Roberto Spadim
::
Rate this Message:
hih4000 are very good, from honneywell a ptfe (teflon - http://en.wikipedia.org/wiki/Polytetrafluoroethylene) filter help it from liquid water, they (filters) are selled with diameters of 1cm, 2cm, 4cm here in brazil, with pore size of .15um filter size to .45um (both works but .15 is slower, like a low pass filter)
2012/2/3 p4trykx <p4trykx@...> Dnia 03-02-2012 o 22:47:26 Mick Sulley <mick@...> napisał(a): -- Roberto Spadim Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by Eloy Paris
::
Rate this Message:
Hi p4trykx,
On 02/03/2012 05:16 PM, p4trykx wrote: > Dnia 03-02-2012 o 22:47:26 Mick Sulley<mick@...> napisał(a): > > I was also thinking about this sensor it has a digital output which can be > connected to uC. There is also DHT22 which has greater range. As I understand it, the DHT22 is the same thing as the RHT03 (see comment #2 from Thomas Liu at http://www.sparkfun.com/products/10167). The DHT11 that Mick found cheap on eBay is the little brother. > From what I read these are based on a capacitor which capacitance is > based on humidity. I wonder how long do they live. I've read that > some types of sensor wear out after about 5 years. No idea about how long these are supposed to leave. Guess only time will tell. >> Thanks for that Eloy, I suspected that would be the case. I would be >> interested to hear your experiences with it when it goes into your >> 'production' environment. > > I'm also looking forward to see it. Sure thing; I hope to be able to share my experiences soon. Cheers, Eloy Paris.- ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
|
|
Re: DHT11 Sensor
by jerry scharf
::
Rate this Message:
On 02/03/2012 02:16 PM, p4trykx wrote:
> Dnia 03-02-2012 o 22:47:26 Mick Sulley<mick@...> napisał(a): > > I was also thinking about this sensor it has a digital output which can be > connected to uC. There is also DHT22 which has greater range. From what I > read these are based on a capacitor which capacitance is based on > humidity. I wonder how long do they live. I've read that some types of > sensor wear out after about 5 years. > > >> Thanks for that Eloy, I suspected that would be the case. I would be >> interested to hear your experiences with it when it goes into your >> 'production' environment. > I'm also looking forward to see it. > > are used in automotive settings and can take quite a bit of abuse. One manufacturer was telling me that the required tests including repeated cycles of freezing the part and then immediately dipping in in very hot oil. ouch! Generally anything with significant failure rates in less than 5 years are not acceptable in automotive environments. Most things other than replaceable parts require a 10+ year average expected life in that market. I have two 15+ year old cars, so I am beginning to worry. (in case you had any doubt, I am a sensor geek.) jerry ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@... https://lists.sourceforge.net/lists/listinfo/owfs-developers |
| Free embeddable forum powered by Nabble | Forum Help |
