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Remote temperature sensors - multiple sensors?
At the moment I have three 'weather stations' which are an indoor
thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? Cheers Dave R |
Remote temperature sensors - multiple sensors?
On 05/03/2013 21:51, Jules Richardson wrote:
On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules if you happen to have every room wired up with lots of ethernet cat5 ports/sockets, you can get modules that do environmental monitoring of server rooms and report back the temperature and humidity to a central monitoring PC. Googling for temperature ethernet sensor yields: http://www.proges.com/en/plug-and-tr...e-sensors.html http://www.audon.co.uk/ethernet_sensors/tme.html http://www.hw-group.com/products/HWg...sensor_en.html if you're really lucky to have PoE on your network, you may be even luckier still to find temperature to ethernet modules that take power from PoE which simplifies installation and setup considerably. |
Remote temperature sensors - multiple sensors?
On 05/03/2013 17:21, David.WE.Roberts wrote:
At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? Cheers Dave R We have got an old Tchibo one - still going strong. And some Oregon ones - two base stations and three remote sensors. Mixed feelings. They work. But are not rechargeable-battery friendly. They don't like the lower voltage and/or outdoor temperatures. That is, they work for a while when freshly charged and at comfortable rather than cold temperatures. Would like to have got decent kit and been able to connect to PC, etc. but could never quite justify it. I am a bit surprised that there does not (yet?) seem to be available a nice little bluetooth temperature sensor - and a nice little price. Or have I missed them? Did see this: http://hackaday.com/2010/12/10/bluet...rature-module/ -- Rod |
Remote temperature sensors - multiple sensors?
"David.WE.Roberts" wrote in message ... At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? I want lots of temperature sensors, for the fridges, freezers, the various batches of beer brewing, oven, room temps in more than one place etc and would like to have a source of decent cheap wifi or bluetooth sensors, just so there isnt a mess of wiring for them. Nothing at all at sensible prices. Hordes of dirt cheap USB temperature sensors, but thats nothing like as easy to use into the PC or whatever because I want them scattered pretty widely. I'd also like a few others with just contact closure etc for stuff like the gates and letterbox lid etc outside. There is one hell of a market there that no chinese person appears to have noticed yet. |
Remote temperature sensors - multiple sensors?
In article ,
"David.WE.Roberts" writes: At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. You will need something to interface the Dallas 1-wire protocol to a serial port or a USB-serial adaptor. A raspberry pi can just about bit-bang the dallas 1-wire protocol with the 1-wire driver included in the Wheezy distro (which will only do a single 1-wire bus AFAIK, but you can have lots of sensors on it), and that's not very expensive. (It occasionally fails to read the 1-wire bus, but you can simply do it again when this happens.) Before doing this I bought a bare 433MHz receiver with a view of decoding the Oregon Scientific signal, but I gave up trying to make that work. (I could see the transmissions on a scope, but they were very hard to separate from noise in software, and I didn't get as far as working out what the encoding was.) -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
Remote temperature sensors - multiple sensors?
On 05/03/2013 19:27, Andrew Gabriel wrote:
In article , "David.WE.Roberts" writes: At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. You will need something to interface the Dallas 1-wire protocol to a serial port or a USB-serial adaptor. A raspberry pi can just about bit-bang the dallas 1-wire protocol with the 1-wire driver included in the Wheezy distro (which will only do a single 1-wire bus AFAIK, but you can have lots of sensors on it), and that's not very expensive. (It occasionally fails to read the 1-wire bus, but you can simply do it again when this happens.) There is also some info on doing it via I2c he http://www.element14.com/community/g...e-raspberry-pi -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
Remote temperature sensors - multiple sensors?
On 05/03/2013 19:27, Andrew Gabriel wrote:
In article , "David.WE.Roberts" writes: At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. The first I bought from Tcibo, and it has been very reliable. The other two are from Lidl/Aldi and both keep losing contact with the external sensor. So not that much good. Not the temperature sensors fighting each other as one was for the camper van and it didn't work well out in a field with nobody else around. Now I would really like to be able to have a number of temperature sensors around the house, both inside and out, and to read all the temperatures at one station, preferably a PC. Now these 'weather stations' are pretty cheap, so the remote sensor must be very cheap. So you would think that you could buy say six budget temperature sensors and a base station for this kind of application. However Google is so far not my friend. Anyone done this kind of thing? I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. You will need something to interface the Dallas 1-wire protocol to a serial port or a USB-serial adaptor. A raspberry pi can just about bit-bang the dallas 1-wire protocol with the 1-wire driver included in the Wheezy distro (which will only do a single 1-wire bus AFAIK, but you can have lots of sensors on it), and that's not very expensive. (It occasionally fails to read the 1-wire bus, but you can simply do it again when this happens.) Before doing this I bought a bare 433MHz receiver with a view of decoding the Oregon Scientific signal, but I gave up trying to make that work. (I could see the transmissions on a scope, but they were very hard to separate from noise in software, and I didn't get as far as working out what the encoding was.) In a similar vein, my house contains a small network of "2-wire" digital temperature sensors based on this design: http://www.riccibitti.com/pc_therm.htm |
Remote temperature sensors - multiple sensors?
On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote:
I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules |
Remote temperature sensors - multiple sensors?
In article ,
Jules Richardson writes: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? Yes, and in the freezer at below -20C. The DS18B20+ does -55°C to +125°C. There are older part numbers with less range and/or less resolution (and most of mine are 10 years old, so are older parts). Maxim/Dallas recommend you always use a separate power rail when using them at high temperatures, as the increased leakage in the package means their capacitor may run flat before completeing the temperature conversion when powered off the data line. When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
Remote temperature sensors - multiple sensors?
On 05/03/13 21:51, Jules Richardson wrote:
On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 00:56:13 +0000, The Natural Philosopher wrote:
On 05/03/13 21:51, Jules Richardson wrote: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Would one of those fit in me garden shed? -- Peter. The gods will stay away whilst religions hold sway |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 00:56:13 +0000, The Natural Philosopher wrote:
On 05/03/13 21:51, Jules Richardson wrote: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Won't, for example, measure the input and output temperature of the air going through my experimental heat transfer system. Or the difference inside and outside the canopy over the veranda. Various product write ups suggest that there may be a maximum of three wireless channels available at 433MHz - unless the industry standard chipset only supports 3. If I was using wired sensors, I should have installed the wires during refurbishment as chopping in new wires now is not going to be popular. Strange that there isn't a budget USB base station with (e.g.) 3 remote temperature sensors as you can buy the stand alone setup from Oregon Scientific for around £40. http://uk.oregonscientific.com/cat-W...d-Offers-prod- Elements-Weather-Station-plus-2-extra-sensors.html#.UTb6EtaeN8E http://tinyurl.com/bm7wpzk Cheers Dave R |
Remote temperature sensors - multiple sensors?
In message , David.WE.Roberts
writes On Wed, 06 Mar 2013 00:56:13 +0000, The Natural Philosopher wrote: I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Won't, for example, measure the input and output temperature of the air going through my experimental heat transfer system. Or the difference inside and outside the canopy over the veranda. Various product write ups suggest that there may be a maximum of three wireless channels available at 433MHz - unless the industry standard chipset only supports 3. If I was using wired sensors, I should have installed the wires during refurbishment as chopping in new wires now is not going to be popular. Strange that there isn't a budget USB base station with (e.g.) 3 remote temperature sensors as you can buy the stand alone setup from Oregon Scientific for around £40. http://uk.oregonscientific.com/cat-W...d-Offers-prod- Elements-Weather-Station-plus-2-extra-sensors.html#.UTb6EtaeN8E http://tinyurl.com/bm7wpzk Somebody gifted me a *remote thermometer alarm kit* made for and purchased from ASDA! (model no 41311) dated 06/08/11 The instructions say that pressing the *CH* button allows you to select a channel (1-3) giving you the option to poll 3 outdoor sensors. There is a miniature jack socket on the sender enclosure but no explanation of any purpose This implies that the remote sender is available separately. The unit looks very much like other Oregon Scientific stuff I have but maybe a knock off? -- Tim Lamb |
Remote temperature sensors - multiple sensors?
On 05/03/2013 19:27, Andrew Gabriel wrote:
I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy |
Remote temperature sensors - multiple sensors?
On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y:
On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... -- Tim Watts Personal Blog: http://squiddy.blog.dionic.net/ http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage Reading this on the web? See: http://wiki.diyfaq.org.uk/index.php?title=Usenet |
Remote temperature sensors - multiple sensors?
On 06/03/2013 10:03, Tim Watts wrote:
On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... I too had forgotten what that was about. Thanks. -- Rod |
Remote temperature sensors - multiple sensors?
On Mar 6, 10:09*am, polygonum wrote:
On 06/03/2013 10:03, Tim Watts wrote: On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... I too had forgotten what that was about. Thanks. -- Rod Not that this is any particular help to the OP, but there's a small module on the market that gives you a serial signal of T and RH - DHT11. They just a bit over a quid each. I don't have the spec in front of me at the moment so I don't know what temperature range they go to. It's a 4 lead device about 10mm square. I'm about to couple a group of them to an Arduino to see if I can cut down the what seems excessive underfloor ventilation here. Rob |
Remote temperature sensors - multiple sensors?
On 06/03/13 07:21, PeterC wrote:
On Wed, 06 Mar 2013 00:56:13 +0000, The Natural Philosopher wrote: On 05/03/13 21:51, Jules Richardson wrote: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Would one of those fit in me garden shed? No. Ive got another remote temperature gauge that's also brilliant. Its attached to the oil tank. It's supposed to tell me how much oil us there, but below -2C it simply stops working. :-) -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Remote temperature sensors - multiple sensors?
On Wednesday, March 6, 2013 10:03:14 AM UTC, Tim Watts wrote:
On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... No what it means is it only needs one port pin on the processor, but still a gimmick in the wording I think. I have two of these sitting next to my sandwiches at the moment. Note that they have 3 pins too ;-) http://www.coolcomponents.co.uk/cata...FaLHtAodCkQAtg -- Tim Watts Personal Blog: http://squiddy.blog.dionic.net/ http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage Reading this on the web? See: http://wiki.diyfaq.org.uk/index.php?title=Usenet |
Remote temperature sensors - multiple sensors?
On Wednesday, 6 March 2013 10:03:14 UTC, Tim Watts wrote:
On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... There are actually three wires! Ground, data and power. Some 1-wire devices can derive enough power from the data wire to run without the power wire, but not all can. 1-wire refers to a single wire being used for data/signal, unlike other hardware protocols which require data + clock at least. I've got multiple 1-wire temperature sensors hanging off my Raspberry Pi. Some distros for the Pi (e.g, Occidentalis) allow 1-wire devices to be connected to a GPIO, but I've got mine working off an I2C 1-wire bus master, which then makes the sensors available through a file-system interface. dan. |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 11:10:55 +0000, The Natural Philosopher wrote:
I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Would one of those fit in me garden shed? No. Ive got another remote temperature gauge that's also brilliant. Its attached to the oil tank. It's supposed to tell me how much oil us there, but below -2C it simply stops working. :-) Prolly needs oiling. -- Peter. The gods will stay away whilst religions hold sway |
Remote temperature sensors - multiple sensors?
On 06/03/13 17:20, PeterC wrote:
On Wed, 06 Mar 2013 11:10:55 +0000, The Natural Philosopher wrote: I've got a brilliant remote temperature sensor. Its called RAF Lakenheath & it tells me how cold it is outside via a widget on the computer :-) Would one of those fit in me garden shed? No. Ive got another remote temperature gauge that's also brilliant. Its attached to the oil tank. It's supposed to tell me how much oil us there, but below -2C it simply stops working. :-) Prolly needs oiling. LMFAO. Nice one. -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 05:56:05 -0800, dwtowner wrote:
On Wednesday, 6 March 2013 10:03:14 UTC, Tim Watts wrote: On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... There are actually three wires! Ground, data and power. Some 1-wire devices can derive enough power from the data wire to run without the power wire, but not all can. 1-wire refers to a single wire being used for data/signal, unlike other hardware protocols which require data + clock at least. I've got multiple 1-wire temperature sensors hanging off my Raspberry Pi. Some distros for the Pi (e.g, Occidentalis) allow 1-wire devices to be connected to a GPIO, but I've got mine working off an I2C 1-wire bus master, which then makes the sensors available through a file-system interface. dan. ....errrr.....a data wire but no clock signal wire? So asynchronous as opposed to synchronous data? Or is it that it is assumed that data is only going in one direction, so the usual minimal TXD, RXD, GND (3 wire) configuration for asynchronous serial data (without any handshaking pins) is cut down to a single data wire plus earth? If I remember my asynchronous communications (RS232 or V.24) which I probably don't after all these years then the signal was a voltage on the data line with respect to earth/ground. I see from above a dedicated power line would be to power the remote device if it had no power source of its own. Taking power from the data line - not sure how this would work but I haven't looked at data comms for some years. Cheers Dave R |
Remote temperature sensors - multiple sensors?
On 05/03/13 17:31, Stephen H wrote:
On 05/03/2013 21:51, Jules Richardson wrote: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules if you happen to have every room wired up with lots of ethernet cat5 ports/sockets, you can get modules that do environmental monitoring of server rooms and report back the temperature and humidity to a central monitoring PC. Googling for temperature ethernet sensor yields: http://www.proges.com/en/plug-and-tr...e-sensors.html http://www.audon.co.uk/ethernet_sensors/tme.html http://www.hw-group.com/products/HWg...sensor_en.html if you're really lucky to have PoE on your network, you may be even luckier still to find temperature to ethernet modules that take power from PoE which simplifies installation and setup considerably. The audon one looks handy. Id like that here.. to remind SWMBO to bring the hose in - especially the nozzle thing - when it goes below freezing. That's one a year she's broken. By the way considering the OP was after shed monitoring, its worth pointing out that you can trail a 100m* of CAT5 and a LV power cable from a wall wart down under the garden easily enough inside a bit of e.g hose or the like. I have to say that I am more and more finding all foirms of RF doint play nice with this house. Distances are too large and tehres to much metal in it. Gimme cat 5 any time. *The length limits on CAT5 are not an issue with a SWITCH as opposed to a HUB, because there are no collision possibilities down a single piece of duplex cable. 10Mbps is easily achievable over that sort of length. -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Remote temperature sensors - multiple sensors?
On 06/03/13 19:45, David.WE.Roberts wrote:
On Wed, 06 Mar 2013 05:56:05 -0800, dwtowner wrote: On Wednesday, 6 March 2013 10:03:14 UTC, Tim Watts wrote: On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... There are actually three wires! Ground, data and power. Some 1-wire devices can derive enough power from the data wire to run without the power wire, but not all can. 1-wire refers to a single wire being used for data/signal, unlike other hardware protocols which require data + clock at least. I've got multiple 1-wire temperature sensors hanging off my Raspberry Pi. Some distros for the Pi (e.g, Occidentalis) allow 1-wire devices to be connected to a GPIO, but I've got mine working off an I2C 1-wire bus master, which then makes the sensors available through a file-system interface. dan. ...errrr.....a data wire but no clock signal wire? So asynchronous as opposed to synchronous data? well that depends on what is on the line. Or is it that it is assumed that data is only going in one direction, so the usual minimal TXD, RXD, GND (3 wire) configuration for asynchronous serial data (without any handshaking pins) is cut down to a single data wire plus earth? It is a very simple very crude BUS system. http://en.wikipedia.org/wiki/1-Wire Not a pint to point bidirectional. Mire HPIB than serial ... If I remember my asynchronous communications (RS232 or V.24) which I probably don't after all these years then the signal was a voltage on the data line with respect to earth/ground. I see from above a dedicated power line would be to power the remote device if it had no power source of its own. Taking power from the data line - not sure how this would work but I haven't looked at data comms for some years. the data line is normally high. an 800pF cap in each slave stores charge when the voltage goes low.. Its designed to be very minimal, pretty slow and needs a master with most of the intelligence. In practice the master IIRC says 'hello XYZ address' and the slave says 'here I am and this is my value' and that's IT. Cutting all power to all devices resets them. Neat huh? Cheers Dave R -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Remote temperature sensors - multiple sensors?
On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote:
In article , "David.WE.Roberts" writes: At the moment I have three 'weather stations' which are an indoor thermometer and clock and atmospheric pressure sensor, and a remote temperature sensor. snip I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. You will need something to interface the Dallas 1-wire protocol to a serial port or a USB-serial adaptor. A raspberry pi can just about bit-bang the dallas 1-wire protocol with the 1-wire driver included in the Wheezy distro (which will only do a single 1-wire bus AFAIK, but you can have lots of sensors on it), and that's not very expensive. (It occasionally fails to read the 1-wire bus, but you can simply do it again when this happens.) Before doing this I bought a bare 433MHz receiver with a view of decoding the Oregon Scientific signal, but I gave up trying to make that work. (I could see the transmissions on a scope, but they were very hard to separate from noise in software, and I didn't get as far as working out what the encoding was.) Do you mean something like http://www.altelectronics.co.uk/projects/p193/ which looks interesting. Cheers Dave R |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 19:50:49 +0000, The Natural Philosopher wrote:
On 05/03/13 17:31, Stephen H wrote: On 05/03/2013 21:51, Jules Richardson wrote: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. cheers Jules if you happen to have every room wired up with lots of ethernet cat5 ports/sockets, you can get modules that do environmental monitoring of server rooms and report back the temperature and humidity to a central monitoring PC. Googling for temperature ethernet sensor yields: http://www.proges.com/en/plug-and-tr...s-on-ethernet/ ethernet-temperature-sensors.html http://www.audon.co.uk/ethernet_sensors/tme.html http://www.hw-group.com/products/HWg-STE/ STE_ip_temperature_sensor_en.html if you're really lucky to have PoE on your network, you may be even luckier still to find temperature to ethernet modules that take power from PoE which simplifies installation and setup considerably. The audon one looks handy. Id like that here.. to remind SWMBO to bring the hose in - especially the nozzle thing - when it goes below freezing. That's one a year she's broken. By the way considering the OP was after shed monitoring, its worth pointing out that you can trail a 100m* of CAT5 and a LV power cable from a wall wart down under the garden easily enough inside a bit of e.g hose or the like. I have to say that I am more and more finding all foirms of RF doint play nice with this house. Distances are too large and tehres to much metal in it. Gimme cat 5 any time. *The length limits on CAT5 are not an issue with a SWITCH as opposed to a HUB, because there are no collision possibilities down a single piece of duplex cable. 10Mbps is easily achievable over that sort of length. Don't recall saying it was for TMOAS - although that might be a possibility. Also, I do have a partially implemented CAT5E cabling scheme to the shed and I also have mains power, water, and drainage. At the moment I have an indoor and an outdoor (in the shade at the end of the garage) temperature monitor from Tchibo which works very well but I now want to monitor a couple of other places as well outside and two or three places inside (but not all the time). It looks as though a 3 sensor package from Oregon might do most of what I want (apart from PC connection). I think that the Oregon kit goes up to 8 channels in some cases, but starts to get expensive. Now rapidly expanding my required reading as I Google more stuff. Cheers Dave R |
Remote temperature sensors - multiple sensors?
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Remote temperature sensors - multiple sensors?
On 6 Mar, 13:56, wrote:
On Wednesday, 6 March 2013 10:03:14 UTC, Tim Watts *wrote: On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... There are actually three wires! Ground, data and power. Some 1-wire devices can derive enough power from the data wire to run without the power wire, but not all can. 1-wire refers to a single wire being used for data/signal, You are confused. unlike other hardware protocols which require data + clock at least. There are no end of protocols that embed clock (or other timing information) and data in the same wire. MBQ |
Remote temperature sensors - multiple sensors?
On 6 Mar, 19:45, "David.WE.Roberts" wrote:
On Wed, 06 Mar 2013 05:56:05 -0800, dwtowner wrote: On Wednesday, 6 March 2013 10:03:14 UTC, Tim Watts *wrote: On Wednesday 06 March 2013 09:51 Andy Champ wrote in uk.d-i-y: On 05/03/2013 19:27, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair Am I the only person trying to work out how "1-wire" means twisted pair? Andy The name is erroneous - a marketing gimmick - it means "1 wire for +ve power and data combined" - you still have a 2nd wire for ground... There are actually three wires! Ground, data and power. Some 1-wire devices can derive enough power from the data wire to run without the power wire, but not all can. 1-wire refers to a single wire being used for data/signal, unlike other hardware protocols which require data + clock at least. I've got multiple 1-wire temperature sensors hanging off my Raspberry Pi. Some distros for the Pi (e.g, Occidentalis) allow 1-wire devices to be connected to a GPIO, but I've got mine working off an I2C 1-wire bus master, which then makes the sensors available through a file-system interface. dan. ...errrr.....a data wire but no clock signal wire? What's wrong with that? So asynchronous as opposed to synchronous data? Isochronous. MBQ |
Remote temperature sensors - multiple sensors?
On Wed, 06 Mar 2013 00:20:23 +0000, Andrew Gabriel wrote:
In article , Jules Richardson writes: On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? Yes, and in the freezer at below -20C. The DS18B20+ does -55°C to +125°C. There are older part numbers with less range and/or less resolution (and most of mine are 10 years old, so are older parts). Ah, that one would work, then. The upper limit's not a problem, but we can occasionally get down to -50C here, and the parts that I looked at wouldn't quite cover the lower limit while still giving a reading at sensible summer temperatures. cheers Jules |
Remote temperature sensors - multiple sensors?
On Wed, 6 Mar 2013 02:54:33 -0800 (PST), robgraham
wrote: Not that this is any particular help to the OP, but there's a small module on the market that gives you a serial signal of T and RH - DHT11. They just a bit over a quid each. I don't have the spec in front of me at the moment so I don't know what temperature range they go to. It's a 4 lead device about 10mm square. I'm about to couple a group of them to an Arduino to see if I can cut down the what seems excessive underfloor ventilation here. You may find that they have too wide a spread to be useful - I intended to display inside and outside loft temperature and humidity and bought three devices. The most closely matched pair (located at same point in loft) show nearly 20% difference:- "Last data on 17/03/2013 at 13:50:17 GMT Environment Loft 5 °C 59 %RH Outside 6 °C 40 %RH " Someone else found same result:- http://www.raspberrypi.org/phpBB3/vi...p?f=37&t=33290 |
Remote temperature sensors - multiple sensors?
Jules Richardson writes:
On Tue, 05 Mar 2013 19:27:01 +0000, Andrew Gabriel wrote: I use dallas 1-wire digital thermometers around the house. These are not wireless, and require a twisted pair to link them all, or 3 conductors, depending if they are driven in 1-wire mode, or with a separate supply line. Any outdoor ones? When I briefly looked at this a couple of years ago, IIRC the Dallas parts were suited toward only part of the potential temperature range, so I was going to have to double up all the sensors (one p/n for colder temps and another for hotter) and read the 'best' one based on the time of year. I can't remember if they outright died beyond their limits, or if it was just that they were only accurate over part of the range. Is this perhaps overkill? One could hook ten cheap low-power silicon diodes in series, pass a more-or less fixed current through them via a resistor from a remote 12 volt source, hook it all up via twisted pair, thin coax, or whatever, and use a rasp or arduino to measure the voltage, which will vary with temperature. One doesn't need precision of 0.1C in most cases. -- Windmill, Use t m i l l J.R.R. Tolkien:- @ O n e t e l . c o m All that is gold does not glister / Not all who wander are lost |
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