On Sun, 27 Jul 2008 03:59:53 +0200, Frank Buss posted:> Ron Ford wrote: > >> This sounds like a piece of hardware. Would it presumably be connected to >> the microcontroller by a wire appropriate for a 1.5-5 volt signal? > > Yes. You can use whatever you have, e.g. something like this one: > > http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1025-ND > >> I would need to measure temperature next to the woodburner and at the other >> end of the house, the part that is "downwind" of the fan. If they're >> inexpensive, I could have more. > > Yes, they are inexpensive: > > http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=568-2051-1-ND > > If you have long wires from the temperature sensor to the microcontroller, > I would recommend a RS485 bus. Add a small microcontroller with UART > support (about $1) and a RS485 driver, like this one: > > http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=497-2080-1-ND > > at each temperature sensor. Then you can connect all temperature sensor > boards in one line with one long 4-pole cable (2 for RS485, GND and supply > voltage). Twisted cables for RS485 is a good idea. On each board you can > add some jumpers to set a RS485 bus address.I'll assume that since no else objected amid a lot of opinions that this is a good way to go. It really helped me to see the pictures that come with these listings. Temperature sensors look like cockroaches with eight legs. The first pin is on the left as you read the name left to right, and it is symmetric about the axis that would be the length. Do these things need to be mounted on a board where they are to measure the temperature, else how do pins interact with wires? -- Unquestionably, there is progress. The average American now pays out twice as much in taxes as he formerly got in wages. 1 H. L. Mencken
computer-driven fans II
Started by ●July 25, 2008
Reply by ●July 28, 20082008-07-28
Reply by ●July 28, 20082008-07-28
On Mon, 28 Jul 2008 00:15:28 -0600, Ron Ford <ron@nowhere.net> wrote:>On Sun, 27 Jul 2008 03:59:53 +0200, Frank Buss posted: > >> Ron Ford wrote: >> >>> This sounds like a piece of hardware. Would it presumably be connected to >>> the microcontroller by a wire appropriate for a 1.5-5 volt signal? >> >> Yes. You can use whatever you have, e.g. something like this one: >> >> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1025-ND >> >>> I would need to measure temperature next to the woodburner and at the other >>> end of the house, the part that is "downwind" of the fan. If they're >>> inexpensive, I could have more. >> >> Yes, they are inexpensive: >> >> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=568-2051-1-ND >> >> If you have long wires from the temperature sensor to the microcontroller, >> I would recommend a RS485 bus. Add a small microcontroller with UART >> support (about $1) and a RS485 driver, like this one: >> >> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=497-2080-1-ND >> >> at each temperature sensor. Then you can connect all temperature sensor >> boards in one line with one long 4-pole cable (2 for RS485, GND and supply >> voltage). Twisted cables for RS485 is a good idea. On each board you can >> add some jumpers to set a RS485 bus address. > >I'll assume that since no else objected amid a lot of opinions that this is >a good way to go.There is (usually) no single best answer. The sensor noted above will offload a lot of the calculations at the cost of some complexity in its interface. Many other options, including (1) volts/degree sensors <http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=TMP36GRTZ-REEL7CT-ND> (2) NTC thermistors <http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=495-2125-ND> (3) thermocouples <http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=TP-29-ND> (4) RTDs <http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=615-1041-ND> (5) thermopiles <http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=MLX90247-ESF-DSA-ND> and I'm sure several more that just fell out of my head this morning. One solution driver will be the expected temperature ranges next to the woodburner and also at the other end of the house. A single sensor or sensor family may not be the best in both situations. Also pay attention to accuracy as well as precision. The SE95 "Ultra High Accuracy" sensor provides 13 bits of precision (0.03 C) but only +/- 2 C of accuracy (depending on temperature range & supply voltage). That's probably a lot-to-lot max/min and individual chips can probably be calibrated more closely.>It really helped me to see the pictures that come with these listings. >Temperature sensors look like cockroaches with eight legs. The first pin >is on the left as you read the name left to right, and it is symmetric >about the axis that would be the length. > >Do these things need to be mounted on a board where they are to measure the >temperature, else how do pins interact with wires?Yep. That's another solution driver. Other sensor types, e.g., thermistors, can be mounted remotely at the end of relatively long wire runs with a (also relatively) negligible effect on the result; 100K ohms for the thermistor, versus say AWG 24 hook-up wire at about 25 ohms per 1000 feet. -- Rich Webb Norfolk, VA
Reply by ●July 28, 20082008-07-28
>> Jeepers Mr Peabody, there's a whole bunch of interface circuitry >> information >> and motor specifics missing!> I have no idea what to even google for to find out more. Who said > "jeepers, mr. peabody," rocky the squirrel?Sherman. JJS
Reply by ●July 28, 20082008-07-28
John Speth wrote:> >>> Jeepers Mr Peabody, there's a whole bunch of interface circuitry >>> information and motor specifics missing! > >> I have no idea what to even google for to find out more. Who said >> "jeepers, mr. peabody," rocky the squirrel? > > Sherman.FYI, those initial lines that say "Joe wrote:" are attribution lines. The attribution line is associated with quoted material lines with one less '>'. This both credits the original author, and uniquely identifies the individual sections. Don't delete them, unless you have deleted all material by that author. Because you snipped attributions, I have no way of knowing who wrote the material with >>> or >> leading the sentences. -- [mail]: Chuck F (cbfalconer at maineline dot net) [page]: <http://cbfalconer.home.att.net> Try the download section.
Reply by ●July 28, 20082008-07-28
Ron Ford wrote:>... snip ...> > It really helped me to see the pictures that come with these > listings. Temperature sensors look like cockroaches with eight legs. > The first pin is on the left as you read the name left to right, > and it is symmetric about the axis that would be the length. > > Do these things need to be mounted on a board where they are to > measure the temperature, else how do pins interact with wires?Of course not. All you have to do is tell the cockroach where to sense the temperature. This requires a clear knowledge of cockroach language, together with clear enunciation. Then you can take proper advantage of the cockroaches extra-sensory perception. -- [mail]: Chuck F (cbfalconer at maineline dot net) [page]: <http://cbfalconer.home.att.net> Try the download section.
Reply by ●July 28, 20082008-07-28
>>>> Jeepers Mr Peabody, there's a whole bunch of interface circuitry >>>> information and motor specifics missing! >> >>> I have no idea what to even google for to find out more. Who said >>> "jeepers, mr. peabody," rocky the squirrel? >> >> Sherman.> Because you snipped attributions, I have no way of knowing who > wrote the material with >>> or >> leading the sentences.Does it really matter? JJS
Reply by ●July 28, 20082008-07-28
In comp.arch.embedded, John Speth <johnspeth@yahoo.com> wrote:>>>>> Jeepers Mr Peabody, there's a whole bunch of interface circuitry >>>>> information and motor specifics missing! >>> >>>> I have no idea what to even google for to find out more. Who said >>>> "jeepers, mr. peabody," rocky the squirrel? >>> >>> Sherman. > >> Because you snipped attributions, I have no way of knowing who >> wrote the material with >>> or >> leading the sentences. > > Does it really matter?Depending on your definition of "really matter" yes...no. But I sure like to know who wrote what, it makes conversations much clearer. In this case I know Chuck wrote the text you replied to, but only because I just read it. If I had seen this message tomorrow, chances are that I had already forgotten that. Do you remember each post you read on usenet and who wrote it? Or do you read back old messages to try to figure out who wrote what? Or do you just don't care who wrote what? -- Stef (remove caps, dashes and .invalid from e-mail address to reply by mail) Future looks spotty. You will spill soup in late evening.
Reply by ●July 29, 20082008-07-29
Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> writes:> John Speth <johnspeth@yahoo.com> wrote:(Actually, Chuck wrote, in response to a post where John had not provided attributions, just like he did when he then replied to Chuck)>>> Because you snipped attributions, I have no way of knowing who >>> wrote the material with >>> or >> leading the sentences. >> >> Does it really matter? > > Depending on your definition of "really matter" yes...no. > > But I sure like to know who wrote what, it makes conversations much > clearer.Indeed. Knowing who wrote what helps the reader decide how much to trust what's written - it's not just what you say, but what you've said in the past (and what others have said about you, and you about them yea back unto the N-th generation) that matters in a reputation-based system like Usenet. When you do not supply attributions for something you quote then instead of serving as backup or counterpoint to what you're saying, it's the equivalent of "I heard somewhere that ...". mlp
Reply by ●July 30, 20082008-07-30
Ron Ford wrote: - snip-> I have no idea what to even google for to find out more. Who said > "jeepers, mr. peabody," rocky the squirrel? >That would be Sherman the Boy. Mr. Peabody was the time-traveling, talking dog (with glasses and a pipe) same Rocky & Bullwinkle program tho.
Reply by ●July 30, 20082008-07-30
On Mon, 28 Jul 2008 14:56:26 -0400, CBFalconer posted:> Ron Ford wrote: >> > ... snip ... >> >> It really helped me to see the pictures that come with these >> listings. Temperature sensors look like cockroaches with eight legs. >> The first pin is on the left as you read the name left to right, >> and it is symmetric about the axis that would be the length. >> >> Do these things need to be mounted on a board where they are to >> measure the temperature, else how do pins interact with wires? > > Of course not. All you have to do is tell the cockroach where to > sense the temperature. This requires a clear knowledge of > cockroach language, together with clear enunciation. Then you can > take proper advantage of the cockroaches extra-sensory perception.This sounds like you're having a little fun with my inexperience. Fair enough, I'm attempting to do something ambitious and am a certifiable neophyte. The cockroaches here on the Rio Grand are commandos with *amazing* superhero abilities. There are so many out on the streets at night that one can sensibly talk about a cockroach pressure around here. They have a meeting with their buddies and then move out in pods. I think they're smarter than your average Texans. -- Unquestionably, there is progress. The average American now pays out twice as much in taxes as he formerly got in wages. 1 H. L. Mencken
