Thermocouples
How would one go about reading a thermocouple with a BS2?
If there are specific chips, please let me know or how anyone does it.
Thanks,
Mark
If there are specific chips, please let me know or how anyone does it.
Thanks,
Mark
Comments
A t-couple outputs a tiny voltage that depends on temperature.
You'll need an amplifier first. Then digitize the value. As for ADCs,
I recommend the Maxim MAX186. It's eight channels of 12 bits of
resolution. Maxim does send samples, checkout hteir webpage for
details.
Paul
on whether you want to use type J or K T'couples.
http://products.analog.com/products/info.asp?product=AD594
http://products.analog.com/products/info.asp?product=AD595
Otherwise, plan on a week of design effort.
Chris
>
Original Message
> From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IdW-d8vmtEAu5ftzbZ5GzCNGXwAbWi0vxGJbEhFc69IJnxPPHQgu_Q0-MHgQ0E6yaMc3i1lgnR6f]madams@a...[/url
> Sent: Friday, November 16, 2001 9:32 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> How would one go about reading a thermocouple with a BS2?
>
> If there are specific chips, please let me know or how anyone does it.
>
> Thanks,
>
> Mark
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> Subject and Body of the message will be ignored.
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>
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> http://docs.yahoo.com/info/terms/
>
>
a BS2p24 and a CIRRUS CS5522 chip.
Chuck
'Program used to measure voltage analog data using a CIRRUS LOGIC CS5522, 24
bit ADC chip
'PARALLAX BS2p24 reads I/O data from the CS5522 thermocouple input (0 to
100mv) channels 1 and 2
'Crystal CS5521/22/23/24 Datatasheet DS317F2 (May '00) page 43, figure 21,
for connection setup
'requires chromel/alumel thermocouple table in program #1, ktab.bsp
'5/7/01
'{$STAMP BS2p,ktab}
dathi var word 'thermocouple 12 bit high address
datlo var word 'thermocouple 12 bit low address
cojhi var word 'cold junction 12 bit high address
cojlo var word 'cold junction 12 bit low address
x var word
y var word
r var word
v var word
s var word
rhi var byte
rlo var byte
rn var byte
'BS2p pin connections to CS5522
SCLK con 11 ' ADC Clock
SDO con 10 ' ADC Data output
SDI con 9 ' ADC Data input
CS con 8 ' Chip select
high CS
pause 500
serout 14,16630,[noparse][[/noparse]254,255] 'turn on lcd backlight
serout 14,16620,[noparse][[/noparse]254,1]
serout 14,16620,[noparse][[/noparse]"Setup for reading a"]
serout 14,16620,[noparse][[/noparse]254,192]
serout 14,16620,[noparse][[/noparse]"thermocouple and a"]
serout 14,16620,[noparse][[/noparse]254,148]
serout 14,16620,[noparse][[/noparse]"cold junction room"]
serout 14,16620,[noparse][[/noparse]254,212]
serout 14,16620,[noparse][[/noparse]"temperatures."]
pause 5000
low CS
gosub RESET 'reset CS5522
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001011] 'read configuration register
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " CONFIG:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
dathi=%000000001000 'write cnfiguration register
datlo=%000000000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000011,dathi\12,datlo\12]
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001011] 'read configuration register
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " CONFIG:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
dathi=%000000001000 'write cnfiguration register
datlo=%000000000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000011,dathi\12,datlo\12]
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001011] 'read configuration register
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " CONFIG:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
dathi=%000001100001 'write cnfiguration register
datlo=%000000000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000011,dathi\12,datlo\12]
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001011] 'read configuration register
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " CONFIG:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
dathi=%100100111010 'write gain register 1 (C/A thermocouple)
datlo=%000000000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00010010,dathi\12,datlo\12]
dathi=%010000000000 'write gain register 2 (LM334 cold
junction)
datlo=%000000000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000010,dathi\12,datlo\12]
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001010] 'read gain register 1
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " GAIN:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
datlo=%000010000011 'write channel setup registers 1 and 2
dathi=%000000001000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000101,dathi\12,datlo\12]
shiftout SDI,SCLK,1,[noparse][[/noparse]%00001101] 'read channel setup register 1
shiftin SDO,SCLK,0,[noparse][[/noparse]dathi\12,datlo\12]
debug " SETUP:",cr,"bits 23 to 12 ",bin12 dathi,cr,"bits 11 to 0 ",bin12
datlo,cr,cr
store 1 'C/A thermocouple data table from 0 to 2000 C
serout 14,16620,[noparse][[/noparse]254,1]
serout 14,16620,[noparse][[/noparse]"BS2p40 reads a LM335"]
serout 14,16620,[noparse][[/noparse]254,192]
serout 14,16620,[noparse][[/noparse]"and C/A Thermocouple"]
REPEAT
shiftout SDI,SCLK,1,[noparse][[/noparse]%10001000] 'activate data reading of channels 1
and 2
pause 500
shiftin SDO,SCLK,0,[noparse][[/noparse]cojhi\12,cojlo\12,dathi\12,datlo\12]
r=(((cojhi<<12)+(cojlo>>0)))
debug " Voltage1 = ",dec r," counts",cr
v=(r/79)-273
serout 14,16620,[noparse][[/noparse]254,148]
pause 1
serout 14,16620,[noparse][[/noparse]dec v," deg C @LM335 "]
debug " Voltage1 = ",dec v," deg C @LM335",cr
s=2*v
read s,rhi
read s+1,rlo
r=(((dathi<<12)+(datlo<<0))*4)-200 'convert to lower 16
bits only
v=r
r=r+(rhi*256)+rlo
dathi=r.highbyte:datlo=r.lowbyte
' debug " Voltage2 = ",dec r," counts",cr
for x=0 to 2000 step 2
read x,y
if y=dathi then aa
next
aa:
for s=x+1 to 2000 step 2
read s,y
read s-1,rn
if dathi<rn then aaa
if y>= datlo then aaa
next
aaa:
s=s/2
debug " Voltage2 = ",dec v," counts ", dec s," deg C @LM2904",cr
pause 1
v=((s*18)/10)+32
serout 14,16620,[noparse][[/noparse]254,212,dec v," deg F @LM2940 "]
goto REPEAT
RESET 'initialize CS5522
shiftout
SDI,SCLK,1,[noparse][[/noparse]$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FE]
dathi=%000000000000 'activate reset in configuration register
datlo=%000010000000
shiftout SDI,SCLK,1,[noparse][[/noparse]%00000011,dathi\12,datlo\12]
return
[noparse][[/noparse]Non-text portions of this message have been removed]
I agree about the AD594 and AD595. With thermocouples, a lot depends
on what range of temperatures you are trying to cover and what
accuracy you need. There are shortcuts if you are going for high
temperatures and/or don't require much accuracy. If you do require
accuracy ( ~1 degree C ), you have to realize that thermocouples are
non-linear and have quite large margins of error that depends on the
purity of the metals. This means a calibration step and a lookup
table or correction formula on the BS2.
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
>If you want to do it in one day, use Analog Devices AD594 or 595, depending
>on whether you want to use type J or K T'couples.
>http://products.analog.com/products/info.asp?product=AD594
>http://products.analog.com/products/info.asp?product=AD595
>
>Otherwise, plan on a week of design effort.
>
>Chris
> >
Original Message
> > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DArfdOgP0e0vkc3r2dkVCl1UP8NhmcW89WXXMGUpRY4quZDUGTMFBTcPtY1O_JPHy1UvTn47aL4poQ]madams@a...[/url
> > Sent: Friday, November 16, 2001 9:32 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > How would one go about reading a thermocouple with a BS2?
> >
> > If there are specific chips, please let me know or how anyone does it.
> >
> > Thanks,
> >
> > Mark
and also the LM335. I really dont need supreme accuracy, but +/-2 or 3C
would be nice.
What would be the advantages of using either one? The LM335 is really cheap
and that looks good. Any drawbacks to it vs. the other?
Mark
Original Message
From: Tracy Allen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=a7p4L_8wEGrSFtqg1idpodBdbrNsPqGt-J_zqj_FYZcV15ThT67cAqfQ8uDni8GyCfJokuiIUpWKQ5Rjcj4]tracy@e...[/url
Sent: Sunday, November 18, 2001 6:28 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
Hi Mark,
I agree about the AD594 and AD595. With thermocouples, a lot depends
on what range of temperatures you are trying to cover and what
accuracy you need. There are shortcuts if you are going for high
temperatures and/or don't require much accuracy. If you do require
accuracy ( ~1 degree C ), you have to realize that thermocouples are
non-linear and have quite large margins of error that depends on the
purity of the metals. This means a calibration step and a lookup
table or correction formula on the BS2.
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
>If you want to do it in one day, use Analog Devices AD594 or 595, depending
>on whether you want to use type J or K T'couples.
>http://products.analog.com/products/info.asp?product=AD594
>http://products.analog.com/products/info.asp?product=AD595
>
>Otherwise, plan on a week of design effort.
>
>Chris
> >
Original Message
> > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=PiBri5a9ZeXraMIHMVEqFZbhhblGBe_OxOzvBuYo5jjctEKhA3T8y8svcXZ2mu4slXi0ac1IaYYtgU0]madams@a...[/url
> > Sent: Friday, November 16, 2001 9:32 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > How would one go about reading a thermocouple with a BS2?
> >
> > If there are specific chips, please let me know or how anyone does it.
> >
> > Thanks,
> >
> > Mark
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of max temp, and its no longer cheap. So, what other devices would anyone
recommend?
Original Message
From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=1WCm0Btjv0HNP3dVmd-OwKGSVdReasjnpIznnw_tZNl5FiVDuBHS7nAdScIjl-fpfs270HDN5WKLB41u]madams@a...[/url
Sent: Monday, November 19, 2001 9:10 AM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
Ok, now I guess I have changed my mind. I have been looking at the DS1820,
and also the LM335. I really dont need supreme accuracy, but +/-2 or 3C
would be nice.
What would be the advantages of using either one? The LM335 is really cheap
and that looks good. Any drawbacks to it vs. the other?
Mark
Original Message
From: Tracy Allen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Z8IZk9KAIT0qCfGpPNGNz4dYfMmglZSb1H8B2dvO62Rq5fPpxpj9i77YBaBPDBgexi2G6luz6teVVUJs]tracy@e...[/url
Sent: Sunday, November 18, 2001 6:28 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
Hi Mark,
I agree about the AD594 and AD595. With thermocouples, a lot depends
on what range of temperatures you are trying to cover and what
accuracy you need. There are shortcuts if you are going for high
temperatures and/or don't require much accuracy. If you do require
accuracy ( ~1 degree C ), you have to realize that thermocouples are
non-linear and have quite large margins of error that depends on the
purity of the metals. This means a calibration step and a lookup
table or correction formula on the BS2.
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
>If you want to do it in one day, use Analog Devices AD594 or 595, depending
>on whether you want to use type J or K T'couples.
>http://products.analog.com/products/info.asp?product=AD594
>http://products.analog.com/products/info.asp?product=AD595
>
>Otherwise, plan on a week of design effort.
>
>Chris
> >
Original Message
> > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=1WCm0Btjv0HNP3dVmd-OwKGSVdReasjnpIznnw_tZNl5FiVDuBHS7nAdScIjl-fpfs270HDN5WKLB41u]madams@a...[/url
> > Sent: Friday, November 16, 2001 9:32 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > How would one go about reading a thermocouple with a BS2?
> >
> > If there are specific chips, please let me know or how anyone does it.
> >
> > Thanks,
> >
> > Mark
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Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=gk0eZN7ePWFJYrJkcXTm9wqOWhozTZwIi6MSrkDd0bg8VmepEw6ziAWBkGWXx295yvrd1ijSyu_ovwmp]chris@m...[/url
> Sent: Monday, November 19, 2001 10:41 AM
> To: 'basicstamps@yahoogroups.com'
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> Did you already describe your application? What temp range do
> you anticipate, what type of environment, what distance
> between sensor and controller, what power source can you use, etc....
> Knowing this will make it easier to apply some basic
> Engineering principles and to suggest alternatives.
>
> Chris
>
> >
Original Message
> > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=NtOcWbS4clN8zz5QBVLnxow2Ww1MkeeNLB2ZcMCnOupwI7jbVyewCt0tRJiYjk9UMdtLCTugSvI]madams@a...[/url
> > Sent: Monday, November 19, 2001 10:17 AM
> > To: basicstamps@yahoogroups.com
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Ok, I keep overlooking small things... the LM135 is the one I
> > need because
> > of max temp, and its no longer cheap. So, what other devices
> > would anyone
> > recommend?
> >
> >
>
It is going in an automotive cooling system, so I will have 12V and 5V to
use. The sensor will be at a maximum of 15ft away from the controller. The
current one I am using is a sensor that varies resistance with temperature,
but it is not that accurate. It is +/-18 degrees and I wanted something a
bit more accurate for about the same price (approx $5) The one I have does
work, but I was looking for alternatives.
I have looked at the LM135 and the TMP04 which does look interesting as
well, but I think you would read the TMP with the pulsein command.
Thanks for the help.
Mark
Original Message
From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Yesp7PSAq6B76pcN6tRhP5d61SgC9bakB5BZNX4TEZZzm1KBdQmAsL2MDuLydT2NHAhCX0vUzgZo7I8]chris@m...[/urlOn Behalf Of Chris
Loiacono (E-mail)
Sent: Monday, November 19, 2001 9:50 AM
To: Basicstamps Group (E-mail)
Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Yesp7PSAq6B76pcN6tRhP5d61SgC9bakB5BZNX4TEZZzm1KBdQmAsL2MDuLydT2NHAhCX0vUzgZo7I8]chris@m...[/url
> Sent: Monday, November 19, 2001 10:41 AM
> To: 'basicstamps@yahoogroups.com'
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> Did you already describe your application? What temp range do
> you anticipate, what type of environment, what distance
> between sensor and controller, what power source can you use, etc....
> Knowing this will make it easier to apply some basic
> Engineering principles and to suggest alternatives.
>
> Chris
>
> >
Original Message
> > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xXLFoEJADbGbnUQ9oB-IK_jeP3LCHMkVOPTXFSaMDAmoI67tqPl83zsgM6gLsWzKxSJM4naa-wOF]madams@a...[/url
> > Sent: Monday, November 19, 2001 10:17 AM
> > To: basicstamps@yahoogroups.com
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Ok, I keep overlooking small things... the LM135 is the one I
> > need because
> > of max temp, and its no longer cheap. So, what other devices
> > would anyone
> > recommend?
> >
> >
>
To UNSUBSCRIBE, just send mail to:
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Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
way, but the LM34a is +/- 2 deg F, and scales easily. The 0831 will send an
8 bit temp value sync serially to the stamp. Scott Edwards did a nice
write-up in his Stamp book with sample code....
Chris
>
Original Message
> From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=3E5WaNMuMFc2IQP0I2Qa0bMGnB2YJdS3AdPsJRrl268cXBP60CGDn28OCALPbPGrQMDCZnlGJZDgZEtUvQ]madams@a...[/url
> Sent: Monday, November 19, 2001 10:51 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> I gave a brief (very brief) a while back, but here is some
> more information.
>
> It is going in an automotive cooling system, so I will have
> 12V and 5V to
> use. The sensor will be at a maximum of 15ft away from the
> controller. The
> current one I am using is a sensor that varies resistance
> with temperature,
> but it is not that accurate. It is +/-18 degrees and I
> wanted something a
> bit more accurate for about the same price (approx $5) The
> one I have does
> work, but I was looking for alternatives.
>
> I have looked at the LM135 and the TMP04 which does look
> interesting as
> well, but I think you would read the TMP with the pulsein command.
>
> Thanks for the help.
>
> Mark
>
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=8MIXIpSHAgeACXtf435t3fef8mqW2UCEhose0VY63pYfU4El8WfrrtPJ0tl9xQhv7gyXPe2xYs3ws9ZPMA]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, November 19, 2001 9:50 AM
> To: Basicstamps Group (E-mail)
> Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
>
>
>
>
> >
Original Message
> > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=8MIXIpSHAgeACXtf435t3fef8mqW2UCEhose0VY63pYfU4El8WfrrtPJ0tl9xQhv7gyXPe2xYs3ws9ZPMA]chris@m...[/url
> > Sent: Monday, November 19, 2001 10:41 AM
> > To: 'basicstamps@yahoogroups.com'
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Did you already describe your application? What temp range do
> > you anticipate, what type of environment, what distance
> > between sensor and controller, what power source can you
> use, etc....
> > Knowing this will make it easier to apply some basic
> > Engineering principles and to suggest alternatives.
> >
> > Chris
> >
> > >
Original Message
> > > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=3E5WaNMuMFc2IQP0I2Qa0bMGnB2YJdS3AdPsJRrl268cXBP60CGDn28OCALPbPGrQMDCZnlGJZDgZEtUvQ]madams@a...[/url
> > > Sent: Monday, November 19, 2001 10:17 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > >
> > >
> > > Ok, I keep overlooking small things... the LM135 is the one I
> > > need because
> > > of max temp, and its no longer cheap. So, what other devices
> > > would anyone
> > > recommend?
> > >
> > >
> >
>
> To UNSUBSCRIBE, just send mail to:
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> Subject and
> Body of the message will be ignored.
>
>
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>
>
>
> To UNSUBSCRIBE, just send mail to:
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> http://docs.yahoo.com/info/terms/
>
>
of what I need to measure. I wanted something that did 250F to give me a
bit of margin.
I am currently using a ADC, so that is not a problem, just looking for the
sensor, or even something to get rid of the ADC. That would be the
ultimate.
Thanks,
Mark
Original Message
From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xwTNetMKfeCHkrgMp6QA4TOTmkM2jV3Nh8XzMZSaaZUFag4rMYxjFall8YmRc1xgGehwA56R_Uk]chris@m...[/urlOn Behalf Of Chris
Loiacono (E-mail)
Sent: Monday, November 19, 2001 10:15 AM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
Did you think about an LM34 and an ADC0831? It may cost a buck or two this
way, but the LM34a is +/- 2 deg F, and scales easily. The 0831 will send an
8 bit temp value sync serially to the stamp. Scott Edwards did a nice
write-up in his Stamp book with sample code....
Chris
>
Original Message
> From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_MS28PM7tlFCGjY-EMjAI6jTg1QmzG8RFGFVXBSWXsq-P6XwlUmYFtK9GnOOp9qfZl_DYStQj1iTuhwJ]madams@a...[/url
> Sent: Monday, November 19, 2001 10:51 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> I gave a brief (very brief) a while back, but here is some
> more information.
>
> It is going in an automotive cooling system, so I will have
> 12V and 5V to
> use. The sensor will be at a maximum of 15ft away from the
> controller. The
> current one I am using is a sensor that varies resistance
> with temperature,
> but it is not that accurate. It is +/-18 degrees and I
> wanted something a
> bit more accurate for about the same price (approx $5) The
> one I have does
> work, but I was looking for alternatives.
>
> I have looked at the LM135 and the TMP04 which does look
> interesting as
> well, but I think you would read the TMP with the pulsein command.
>
> Thanks for the help.
>
> Mark
>
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xwTNetMKfeCHkrgMp6QA4TOTmkM2jV3Nh8XzMZSaaZUFag4rMYxjFall8YmRc1xgGehwA56R_Uk]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, November 19, 2001 9:50 AM
> To: Basicstamps Group (E-mail)
> Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
>
>
>
>
> >
Original Message
> > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xwTNetMKfeCHkrgMp6QA4TOTmkM2jV3Nh8XzMZSaaZUFag4rMYxjFall8YmRc1xgGehwA56R_Uk]chris@m...[/url
> > Sent: Monday, November 19, 2001 10:41 AM
> > To: 'basicstamps@yahoogroups.com'
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Did you already describe your application? What temp range do
> > you anticipate, what type of environment, what distance
> > between sensor and controller, what power source can you
> use, etc....
> > Knowing this will make it easier to apply some basic
> > Engineering principles and to suggest alternatives.
> >
> > Chris
> >
> > >
Original Message
> > > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_MS28PM7tlFCGjY-EMjAI6jTg1QmzG8RFGFVXBSWXsq-P6XwlUmYFtK9GnOOp9qfZl_DYStQj1iTuhwJ]madams@a...[/url
> > > Sent: Monday, November 19, 2001 10:17 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > >
> > >
> > > Ok, I keep overlooking small things... the LM135 is the one I
> > > need because
> > > of max temp, and its no longer cheap. So, what other devices
> > > would anyone
> > > recommend?
> > >
> > >
> >
>
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since I am not a walking datasheet resource, I don't know what the temp
range is. The nice feature is that you would have sensor and direct digital
output from an 8-pin device. Wiring the 15 ft. run may be a bit more of a
challenge......
Chris
>
Original Message
> From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xc5ABq6QgsZ8dO8BaoefYfNcrIxC07dzYeXp5TyJdLCcXAEdMJGN2iDt5xn-OtCgUOUCfBOXcIUmlzYg]madams@a...[/url
> Sent: Monday, November 19, 2001 11:14 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> Ok, just looked that one up and its max is 230F which is
> right on the edge
> of what I need to measure. I wanted something that did 250F
> to give me a
> bit of margin.
>
> I am currently using a ADC, so that is not a problem, just
> looking for the
> sensor, or even something to get rid of the ADC. That would be the
> ultimate.
>
> Thanks,
current which is a little less noisy in automobile applications. They
can be had for about $5.
Allan
Original Message
From: Mark Adams <madams@a...>
Date: Monday, November 19, 2001 8:51 am
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> I gave a brief (very brief) a while back, but here is some more
> information.
> It is going in an automotive cooling system, so I will have 12V
> and 5V to
> use. The sensor will be at a maximum of 15ft away from the
> controller. The
> current one I am using is a sensor that varies resistance with
> temperature,but it is not that accurate. It is +/-18 degrees and
> I wanted something a
> bit more accurate for about the same price (approx $5) The one I
> have does
> work, but I was looking for alternatives.
>
> I have looked at the LM135 and the TMP04 which does look
> interesting as
> well, but I think you would read the TMP with the pulsein command.
>
> Thanks for the help.
>
> Mark
>
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DgM1KyCxy_rKBOrfmMTpfrv2V_0tqlcXNQTCQpRx_lsP79fx8z_lLIAWa30RI0FDLzHYqlZKBZa1PO6TzA]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, November 19, 2001 9:50 AM
> To: Basicstamps Group (E-mail)
> Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
>
>
>
>
> >
Original Message
> > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DgM1KyCxy_rKBOrfmMTpfrv2V_0tqlcXNQTCQpRx_lsP79fx8z_lLIAWa30RI0FDLzHYqlZKBZa1PO6TzA]chris@m...[/url
> > Sent: Monday, November 19, 2001 10:41 AM
> > To: 'basicstamps@yahoogroups.com'
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Did you already describe your application? What temp range do
> > you anticipate, what type of environment, what distance
> > between sensor and controller, what power source can you use,
> etc....> Knowing this will make it easier to apply some basic
> > Engineering principles and to suggest alternatives.
> >
> > Chris
> >
> > >
Original Message
> > > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9LsbEx85cVvE8VIiAA4EwUOCS94PCIj7ZMJvDi_HwXzTWn_Hp3G0Mrurz15QRaDx-VsqJnoWqjWXmQk]madams@a...[/url
> > > Sent: Monday, November 19, 2001 10:17 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > >
> > >
> > > Ok, I keep overlooking small things... the LM135 is the one I
> > > need because
> > > of max temp, and its no longer cheap. So, what other devices
> > > would anyone
> > > recommend?
> > >
> > >
> >
>
> To UNSUBSCRIBE, just send mail to:
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>
notes. They have a amp in there that makes it 100mV/C that would require
15V for 150C operation. I guess I could use the 12V to give 120C which is
the top of where I want to measure.
I am going to have to come up with an equation anyway to get the 1mV/c or
100mV/C to display on the LCD anyway, so I could use 50mV or anything I
wanted.
Thanks for all the ideas and definately keep them coming.
Mark
Original Message
From: aldobler@s... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VMkX6j7lKOAhNpLhYxZoOxJE71sZ67YecdIbYmmN2TigrjOULuph6Czg3jDxKtipfkpeUNTa1A]aldobler@s...[/url
Sent: Monday, November 19, 2001 10:54 AM
To: basicstamps@yahoogroups.com
Subject: Re: RE: [noparse][[/noparse]basicstamps] Thermocouples
I use the AD590 for most of my temp measurements. It outputs a uA
current which is a little less noisy in automobile applications. They
can be had for about $5.
Allan
Original Message
From: Mark Adams <madams@a...>
Date: Monday, November 19, 2001 8:51 am
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> I gave a brief (very brief) a while back, but here is some more
> information.
> It is going in an automotive cooling system, so I will have 12V
> and 5V to
> use. The sensor will be at a maximum of 15ft away from the
> controller. The
> current one I am using is a sensor that varies resistance with
> temperature,but it is not that accurate. It is +/-18 degrees and
> I wanted something a
> bit more accurate for about the same price (approx $5) The one I
> have does
> work, but I was looking for alternatives.
>
> I have looked at the LM135 and the TMP04 which does look
> interesting as
> well, but I think you would read the TMP with the pulsein command.
>
> Thanks for the help.
>
> Mark
>
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=n1Ux7HuaUz2t7V0gOrwKZy9AlwlOrfZzg1x7rxBJyoYAC1KdC8FdmbRk1lVOgpUGhRmh2RX1JaYU]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, November 19, 2001 9:50 AM
> To: Basicstamps Group (E-mail)
> Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
>
>
>
>
> >
Original Message
> > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=n1Ux7HuaUz2t7V0gOrwKZy9AlwlOrfZzg1x7rxBJyoYAC1KdC8FdmbRk1lVOgpUGhRmh2RX1JaYU]chris@m...[/url
> > Sent: Monday, November 19, 2001 10:41 AM
> > To: 'basicstamps@yahoogroups.com'
> > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> > Did you already describe your application? What temp range do
> > you anticipate, what type of environment, what distance
> > between sensor and controller, what power source can you use,
> etc....> Knowing this will make it easier to apply some basic
> > Engineering principles and to suggest alternatives.
> >
> > Chris
> >
> > >
Original Message
> > > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=y2gn0dryYL0PQuKduV-8ECJiyacDHrUbhOmlqVn9sF-0h0W_XJYBnGPyLNCUFtESzCknDKbaOgG0Eg]madams@a...[/url
> > > Sent: Monday, November 19, 2001 10:17 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > >
> > >
> > > Ok, I keep overlooking small things... the LM135 is the one I
> > > need because
> > > of max temp, and its no longer cheap. So, what other devices
> > > would anyone
> > > recommend?
> > >
> > >
> >
>
> To UNSUBSCRIBE, just send mail to:
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> Subject and
> Body of the message will be ignored.
>
>
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> http://docs.yahoo.com/info/terms/
>
>
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> basicstamps-unsubscribe@yahoogroups.com
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> Subject and Body of the message will be ignored.
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>
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resistor will give you 2.732 Volts. (or 0.273V with a 1K resistor)
Measured with a 12 bit A/D (Maxim MAX187, order your free samples) with
a 4.096V reference will give you a count of 2732. Subtract 2732 from
your total, and you get 0.1C resolution.
The highest temp you can read with this setup is 136.3 C. (4.095 -
2.732)
They work from –55C to +150C. There are several grades available,
depending on your pocketbook. The cheapest ones are about +/-1.5 deg C
acurate. I calibrate them with a know good thermometer, and add or
subtract the calibration factor in a math equation.
degreesC = degreesK - (2732 + CalFactor)
Of course the tenths decimal place in inserted when the output is being
formatted for the LCD display.
The calibration factor appears quite linear over a reasonable
temperature range. Experiment and see.
The downfall of these are the TO-39 housing which presents mounting
challenges. I soldered mine to a copper penny, and then bolted that to
a waterpump flange.
http://www.analog.com/pdf/1186_b.pdf
Allan Dobler
Original Message
From: Mark Adams <madams@a...>
Date: Monday, November 19, 2001 10:29 am
Subject: RE: RE: [noparse][[/noparse]basicstamps] Thermocouples
> But does this require all the compensation circuits used in the
> applicationnotes. They have a amp in there that makes it 100mV/C
> that would require
> 15V for 150C operation. I guess I could use the 12V to give 120C
> which is
> the top of where I want to measure.
>
> I am going to have to come up with an equation anyway to get the
> 1mV/c or
> 100mV/C to display on the LCD anyway, so I could use 50mV or
> anything I
> wanted.
>
> Thanks for all the ideas and definately keep them coming.
>
> Mark
>
>
Original Message
> From: aldobler@s... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VMj9S6Wt4l_sJmJ8uRgiWtiV7rHoDEmQRKtGjGgFD7Nr_Cunw1DKwDe56axJciKTYMab770b11kvqtc]aldobler@s...[/url
> Sent: Monday, November 19, 2001 10:54 AM
> To: basicstamps@yahoogroups.com
> Subject: Re: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
>
> I use the AD590 for most of my temp measurements. It outputs a uA
> current which is a little less noisy in automobile applications. They
> can be had for about $5.
>
> Allan
>
>
Original Message
> From: Mark Adams <madams@a...>
> Date: Monday, November 19, 2001 8:51 am
> Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
>
> > I gave a brief (very brief) a while back, but here is some more
> > information.
> > It is going in an automotive cooling system, so I will have 12V
> > and 5V to
> > use. The sensor will be at a maximum of 15ft away from the
> > controller. The
> > current one I am using is a sensor that varies resistance with
> > temperature,but it is not that accurate. It is +/-18 degrees and
> > I wanted something a
> > bit more accurate for about the same price (approx $5) The one I
> > have does
> > work, but I was looking for alternatives.
> >
> > I have looked at the LM135 and the TMP04 which does look
> > interesting as
> > well, but I think you would read the TMP with the pulsein command.
> >
> > Thanks for the help.
> >
> > Mark
> >
> >
Original Message
> > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_90jxjVsKmMmUeJtptPOy-1hgMtfrJyTDrrvauU8IuBlvxbsOoqae3JSmQz62fKRUwqPQrIXNZY8Y-x2]chris@m...[/urlOn Behalf Of Chris
> > Loiacono (E-mail)
> > Sent: Monday, November 19, 2001 9:50 AM
> > To: Basicstamps Group (E-mail)
> > Subject: FW: [noparse][[/noparse]basicstamps] Thermocouples
> >
> >
> >
> >
> > >
Original Message
> > > From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_90jxjVsKmMmUeJtptPOy-1hgMtfrJyTDrrvauU8IuBlvxbsOoqae3JSmQz62fKRUwqPQrIXNZY8Y-x2]chris@m...[/url
> > > Sent: Monday, November 19, 2001 10:41 AM
> > > To: 'basicstamps@yahoogroups.com'
> > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > >
> > >
> > > Did you already describe your application? What temp range do
> > > you anticipate, what type of environment, what distance
> > > between sensor and controller, what power source can you use,
> > etc....> Knowing this will make it easier to apply some basic
> > > Engineering principles and to suggest alternatives.
> > >
> > > Chris
> > >
> > > >
Original Message
> > > > From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VRNddbBLz1q9Q8_Xef5QkQeWb4j9iPwHE49eI_3aWUyLb3QMhUlDmyfeFspwvVLcmXFpDh4euhw]madams@a...[/url
> > > > Sent: Monday, November 19, 2001 10:17 AM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> > > >
> > > >
> > > > Ok, I keep overlooking small things... the LM135 is the one I
> > > > need because
> > > > of max temp, and its no longer cheap. So, what other devices
> > > > would anyone
> > > > recommend?
> > > >
> > > >
> > >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> > Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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used to measure water temperature in the Earth Measurements unit for
Stamps-in-class.
http://www.emesys.com/EarthM/em3.pdf
http://www.emesys.com/OWL2face.htm#AD590
You can use RCtime to read its output (which is a current). You do
not absolutely need to use an analog to digital converter. You do
not need the resistor to convert it to a voltage or any kind of
amplifier. The interface to the Stamp can be very easy to implement
if you can accept +/- 1 or 2 degrees accuracy. All you need is one
capacitor and one resistor and the AD590. The notes describe the
interface and the math.
There is a description of how to mount it onto a cable posted at,
http://www.emesys.com/tk_fab.htm
That actually describes the construction for the AD592 used in the
Earth Measurements series for water temperature. The AD592 and the
AD590 are similar except for packaging. The AD590 is in a metal
case, which covers the wider temperature range that you are looking
for. The mounting to a flange would take some ingenuity, as Allan
suggested.
-- best regards
Tracy Allen
electronically monitored ecosystems
http://www.emesystems.com
mailto:tracy@e...
>The AD590 outputs 273.2uA at 273.2K (0 Celcius). Measured across a 10k
>resistor will give you 2.732 Volts. (or 0.273V with a 1K resistor)
>
>Measured with a 12 bit A/D (Maxim MAX187, order your free samples) with
>a 4.096V reference will give you a count of 2732. Subtract 2732 from
>your total, and you get 0.1C resolution.
>
>The highest temp you can read with this setup is 136.3 C. (4.095 -
>2.732)
>
>They work from
Here's waht I know about DS1620 (from DALLAS Semiconductor) :
- range : -55°C to +125°C (0.5 °C increments) or -67°F to + 257 °F (0.9 °F
increments)
- supply from 2.7 to 5.5 volts
- temperature is read as a 9-bit value
- measure time = 1 second
- 3-wire interface (clock, data, reset)
I use it for a central heatig control without any problem...
Phil.
Original Message
From: "Chris Loiacono (E-mail)" <chris01@t...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, November 19, 2001 5:51 PM
Subject: RE: [noparse][[/noparse]basicstamps] Thermocouples
> OK, you might try (If you haven't already) DS1620 (or is it 1621?), but
> since I am not a walking datasheet resource, I don't know what the temp
> range is. The nice feature is that you would have sensor and direct
digital
> output from an 8-pin device. Wiring the 15 ft. run may be a bit more of a
> challenge......
>
> Chris
>