Temperature controlled relay

TCLynx

Member
Ok, another fairly basic project I want to take on. I want to be able to cut power to a circuit if the water temperature gets too low in the fish tank. I have an automatic fish feeder on an outdoor system. There is a timer powering the feeder so it isn't really as easy as buying a thermostat to plug between the power and the feeder since I want the timer to keep it's schedule and most of those thermostats would probably not react fast enough if they didn't have power until the timer turned on.

So the control probably needs separate power from the feeder but have it control a relay that will not allow the feeder to get power if the temperature is too low for the fish to eat. (Ideally I would be able to manually adjust things but unfortunately I travel too much and our weather here can be very crazy through the winter so I don't really want to "not feed at all" while I'm gone but that will be the solution if I can't build something.

I've already successfully made a picaxe repeat cycle timer relay that has been working very well for me and I always hear people say that temperature control is an easy one so I think I'll jump in and try it.

So, I did some searching and not quite finding the examples I probably need. Please point me to some threads or tips that will help get me started. I understand basic power supply for the chips and how to deal with relays. What I need to know is how to hook up a temp sensor (what kind would be best? temp range between 32 F and 100 F more or less) and how to program to say turn off the relay if the temp falls below 45 F and turn it back on when the temp comes up to 50 F and whatever timing I need to keep from chattering the relay near the set points.

Some day I might want to create something a bit more elaborate with sensors and a relay board or at least some way to data log temperatures and load them to a computer or the internet but one step at a time.
 

Sifty

New Member
I am trying to do something similar for my turtles tank.

I have that sensor. But I have a problem:
When you write:

Readtemp 1,b0,
If B0 > 9 then

1, in 28x2 which number of leg is? I can't try the program in picaxe developer with test temperature or something like that, it never finds the detector...
 

hippy

Senior Member
For the X2 and M2 the pins are labelled as port.pin - Simply use the port.pin you have / want the DS18B20 connected to, so, if it's on C.3 ...

ReadTemp C.3, b0

rather than

ReadTemp 1, b0
 

TCLynx

Member
Cool, thanks for the tips

I wonder if I could actually have my timer chip also handle this program as well?
 

russbow

Senior Member
If you mean this timer chip.............

I've already successfully made a picaxe repeat cycle timer relay that has been working very well for me and I always hear people say that temperature control is an easy one so I think I'll jump in and try it.
........... then, if you have a spare input pin, yes. Just follow the tips above.
 

TCLynx

Member
yea, the timer uses almost nothing and pins 3 (in/out4), 4 (in 3), 5 (in/out2), and 7 (out 0) are doing nothing. So I could probably use pin 4 as the in for the temp sensor and pin 3 or 5 as the output to drive the temp controlled relay.

Here is the thread to the timer circuit I've been using http://www.picaxeforum.co.uk/showthread.php?t=16000

And the diagram
 

TCLynx

Member
Ok, looking at some examples of programing for a temp controller, I'm still having trouble getting my mind around it.

I don't need it to check the temperatures too often. Here is the current code running my repeat cycle timer

Code:
Top:
for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
goto Top
I could slip the code for the temp control into this somewhere so it would only be checking the temp about every ten minutes.

So the timer is using IO 1 (pin 6) to control that relay.

Can I use IO 4 (pin 3) as my input for the temp sensor?
Can I use IO 2 (pin 5) as my output to control another relay?

I want IO 2 to stay low as long as the temperature is above 50 F (10 C) and it would go high when the temp drops below 50 F. I don't want it to go low again until the temperature is above 57 F (14 C)

Any tips of other projects I should look at to help me figure out how to program this?
 

TCLynx

Member
So let me see if I can figure out some code for the temp control.

Code:
readtemp 4,b3
if b3 < [COLOR="Red"]10 C[/COLOR]
high 2
if b3 > [COLOR="Red"]14 C[/COLOR]
low 2
The parts of the code in red are just the temps that I'm not really sure how to write it in here.
 

TCLynx

Member
My brain hurts. I probably need some extra explanation of some of this.
I found this http://www.phanderson.com/picaxe/ds18b20_08m.html
which is more complex than I need but it gives me a start point if I can figure it out.
Program DS18B20_08M_3

Discussion to be added.

' DS18B20_08M_3.Bas - PICAXE-08M
'
' Illustrates an interface with the DS18B20 in monitoring two temperatures. An alarm
' is associated with with one of the temperatures.
'
' Continually measures the temperature and displays to two significant digits on the
' terminal. This is repeated for DS18B20 temperature sensors on IN1/OUT1 and IN2/OUT2.
'
' If the temperature measured on the DS18B20 associated with IN1 is abve HighTrip, a relay
' on Out4 (term 3) is operated. It is released when the temperature falls below LowTrip
'
' Note that HighTrip and LowTrip are specified as the temperature plus 60 degrees C to avoid
' working with negative numbers.
'
'
' Note that a 4.7K pullup to +5 VDC is required on each DQ lead. +5 VDC is required on the
' V+ terminal of the DS18B20.
'
' 08M DS18B20
'
' IO1 (term 7) ------------------ DQ (term 2)
' IO2 (term 6) ------------------ DQ (term 2)
'
' ALM LED
' OUT4 (term 3) ------- 330 ----->|---- GRD
'
' Uses 138 of 256 bytes.
'
' copyright, Peter H Anderson, Baltimore, MD, Sept, '04

Symbol TReading = W0
Symbol Whole = B2
Symbol Fract = B3
Symbol SignBit = B4
Symbol Dig = B5
Symbol TempC_100 = W3
Symbol DevNum = B8
Symbol Temp_8 = B9

Symbol HighTrip = 90 ' 30 + 60 - adjust as necessary
Symbol LowTrip = 88 ' 28 + 60

Low 4 ' turn off alarm
Top:
For DevNum = 1 to 2 ' 1, 2
Branch DevNum, (Invalid, Dev1, Dev2)

Invalid:

Dev1:
ReadTemp12 1,TReading
ReadTemp 1, Temp_8 ' read the high 8 bits
Goto CalcT
Dev2:
ReadTemp12 2,TReading
Goto CalcT

CalcT:
SignBit = TReading / 256 / 128
If SignBit = 0 Then Positive
' its negative
TReading = TReading ^ $ffff + 1 ' take twos comp

Positive:

TempC_100 = TReading * 6 ' TC = value * 0.0625
TReading = TReading * 25 / 100
TempC_100 = TempC_100 + TReading

GoSub DisplayTemp
Next

' now deal with the alarm
Temp_8 = Temp_8 + 60 ' to avoid negative numbers
If Temp_8 > HighTrip Then OperateAlarm
If Temp_8 < LowTrip Then ReleaseAlarm
' else
Goto SequenceDone

OperateAlarm:
High 4
Goto SequenceDone

ReleaseAlarm:
Low 4
Goto SequenceDone

SequenceDone:
Pause 20000
GoTo Top

DisplayTemp:

SerTxD (#DevNum, " ")
Whole = TempC_100 / 100
Fract = TempC_100 % 100
If SignBit = 0 Then DisplayTemp_1
SerTxD ("-")

DisplayTemp_1:

SerTxD (#Whole, ".")
' be sure the fractional is two digits
Dig = Fract / 10
SerTxD (#Dig)
Dig = Fract % 10
SerTxD (#Dig, 13, 10)

Return
I'm sure I don't need most of this since I'm not outputting any display and I'm only using one sensor to control a relay.

Let me see if I can make some useful code out of this.
So this is the temperature control code along with the timer code running at the end. So hopefully it will turn off the power to my fish feeder if the temperature is below 14 C and leave it on when the temps are above that and will check the temp about every ten minutes (basically between the timer cycles, the timer is operating a relay on output 1 while I'm thinking to have the temp sensor on input/output 4 and the relay operating the feeder circuit on output 2. I'm leaving the outputs low for the greatest time and using the relays in NC as much as possible so as to use the least power for the control of everything.)

Code:
    Symbol Temp_8 = B3
    Symbol Trip = 74		' 14 + 60
   
Top:
      ReadTemp 4, Temp_8	' read the high 8 bits - approx temp in deg C

    ' respond to the temperature
    Temp_8 = Temp_8 + 60	' to avoid negative numbers
    If Temp_8 >= Trip Then OperateFeeder
    If Temp_8 < Trip then StopFeeder

OperateFeeder:
    Low 2
    Goto Timer

StopFeeder:
    High 2
    Goto Timer

Timer:
for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
    GoTo Top
Will this work or do I need all the extra symbols and calculations in here?
Anyone see any glaring mistakes or problems? I must admit that I'm really confused as to how I'm supposed to figure out the readings from the sensor or how the chip is actually understanding it.
 
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eclectic

Moderator
@TCLynx
your code in post #8
Code:
Top:
for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
goto Top
could be simplified and shortened using the
SLEEP command (M2 p.223)
Code:
Top:
sleep 260 ;260 x 2.3 = 600 sec
goto Top
It may need a little calibration for the 260 value
e
 

russbow

Senior Member
@TCL, make it easy for yourself. Build on what you've got and forget post #10.

Your timer program works so keep it.

You've sorted the hardware out, Dr A suggests it's perfect so keep it.

You've broken the back of the readtemp, so put it all together.

consider a Gosub routine to read the temperature ( manual 3 page 70 ).

Maybe pop it in the current program after Top: line

Your structure would look like this -

Code:
Top:

[COLOR="Red"]Gosub get_temp[/COLOR]

for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
goto Top

[COLOR="red"]Get_temp:

readtemp 4,b3
if b3 <10 then high 2
endif
if b3 > 14  then low 2
endif

Return[/COLOR]
This will set pin 2 high if the temperature is less than 10 degrees and low if it is greater than 14 degrees. Remember, readtemp is in degrees C.

I don't think this is really what you are trying for, but a good jumping off point.
 

TCLynx

Member
Hum, for some reason I'm not getting any e-mail notifications of new posts to this thread (which I am subscribed to) anyway...

Russbow, that suggestion actually sounds pretty good. The code I did in the bottom of my post #10 I think might work and is certainly small enough for the chip but your suggestion actually looks good to me too.

When I get the rest of the parts (sensor) I'll actually hook it up and test it out and get back to you all then.

Good to know I've got the basic idea sorted out:)

eclectic, the timer code I've kinda left as it is because it makes it easy for my poor brain to get around adjusting the timing by adding or removing a loop basically. I expect if I need to add more stuff to this little chip then I'll need to take your advice though as I start filling up the space. Thanks
 

russbow

Senior Member
Sorry, I didn't read the bottom of post 10. :)

your code ( for the Picaxe 08m ) looks good.

Code:
#picaxe08m
 Symbol Temp_8 = B3
    Symbol Trip = 74		' 14 + 60
   
Top:
      ReadTemp 4, Temp_8	' read the high 8 bits - approx temp in deg C

    ' respond to the temperature
    Temp_8 = Temp_8 + 60	' to avoid negative numbers
    If Temp_8 >= Trip Then OperateFeeder
    If Temp_8 < Trip then StopFeeder

OperateFeeder:
    Low 2
    Goto Timer

StopFeeder:
    High 2
    Goto Timer

Timer:
for b1 = 1 to 9 
low 1
'pause 60000 
next b1
high 1
for b2 = 1 to 2 
'pause 30000 
next b2
    GoTo Top
works fine in the sim and only takes 44 bytes. Well done.
 

TCLynx

Member
Thanks:eek:
You guys are great here. I think I'll be doing a blog post on my site soon about how I've used the picaxe 08M for my repeat cycle timer and then later once I test out the temperature control add on I'll do another about that too:D
 

william47316

New Member
heres some code i used on the 08M and a dallas 18b20, full 12bit temperature reading does positive and negitive with settable warning level between 1 and 125 degrees when it gets to the set level you can get it to do something or stop doing something until it gets below that
the code was made for my 8 digit display but should be reasonably modifiable to use a standard serial display or LCD just replace and add a few character codes here and there and or change some code around

Code:
symbol degcelraw = w3
'b2,3 in use
symbol warntemp = b4
symbol degcel = b1
symbol degceldec = b0
'symbol degfarn = w2
eeprom 0,(9,8,7,6,5,4,3,2,1,0) 'lookup table for the negitive decimals
main:
readtemp12 1,degcelraw
'put in default state you want here eg high on a pin
degcel = degcelraw/16 'calculate into deg celcius
degceldec = degcelraw//16*10/16
b3 = 0 'for positive temperatures default to show blank
'code for positive 43 (+) for standard serial
'negitive temperature code
if degcel >= $7F then' if the degcel var is above 127 (max reading for +'ve is 125°C below zero "underflows" to 65535 @ -0.1 ish °C)
degcel = 255 - degcel 'take it from 255
b2 = degceldec
read b2, degceldec 'read the value of the decimal point from eeprom
b3 = 58 ' set b3 to show the "colon" character (dash)
'code for negative 45 (-)
end if
'end of negitive temperature processing

'decimal point selection code
b2 = 83
if degcel < 10 then
b2 = 82
end if
if degcel >= 100 then
b2 = 84
end if
'end of decimal point selection code
if degcel >= warntemp then
if warntemp <> 0 then
b3 = 7
'insert High or low command (s) here and comment the b3 = 7

end if
end if
'replace the codes for positive with 43 (+) and negitive with 45 (-)
'and the K with ° for standard serial 
sertxd (b2,b3,#degcel,#degceldec,"KCEL") 'serial out the lot and some filler
'sertxd (#degcelraw,"RAKC") 'uncomment this and (or) comment above out for debugging code
if input3 = 1 or input4 = 1 then adjust
goto main

adjust:
for b5 = 1 to 8
sertxd (#warntemp,"KCADJ:::")

if input4 = 1 then
b5 = 1
inc warntemp
if warntemp >= 125 then
warntemp = 125
end if
pause 315
goto adjust
end if

if input3 = 1 then
b5 = 1

if warntemp = 0 then
warntemp = 0
goto main
end if

dec warntemp

pause 315
goto adjust
end if
pause 315
next
goto main
 
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TCLynx

Member
Still haven't picked up the part to finish this project yet but I've been cleaning up the electronics tinkering project shelf/box today and I might have another sit down in front of making a power supply.

I have a transformer that was sent to me for signing up with a components company so I just need to get some other parts and perhaps I can clean up the package enough to fit it into some sort of box. Right now it's kinda a mess with a wall wart plus the mains power to a relay to plug in the pump and then I'll have another mains power to another relay to control the feeder (can't really change the feeder side as that has to be plugged into the feeder timer) but would be nice to tidy things up a bit more.
 

TCLynx

Member
Just thought I'd let everyone know that I did get the temp sensor and have modified the circuit board, adding it in and hooked up another box with the new relay and given it all a quick test once I got the new program onto the chip.

Seems to work. Ran it with the temp sensor at room temp with lamps hooked to the relays. The timer relay still works as it should and after each round of the timer it checks the temp. Then I stuck the sensor in a bag and sunk that down into a container of ice water and after the next round of the timer, the feeder relay opened so it seems to be working at least roughly.

Now to keep painting the sensor and wires with liquid e-tape for a while so that it won't freak out being sunk into the fish tank.

Oh, the transistors used in the actual project are not quite the same as the ones in the diagram. I actually wound up using 2N2222 cause that is what radio shack had.

Will probably put it into service in the next few days.
 

John West

Senior Member
I'd comment on the appropriateness of the 2N2222, but your schematic doesn't mention any specs on the relay coil.
 

TCLynx

Member
Please comment. The relays I'm using are 12 volt relays. The original one I used on the timer is SRU-12VDC-SD-C and the contacts, it says it is good for 15A at 125VAC so well within my needs for switching a little 50 watt mag drive pump. I believe in the original timer thread there was some discussion about what sort of transistor I would need and without looking back through that thread, I vaguely remember some one telling me to measure something on the relay to figure out what sort of transistor and resistors to use with it. Anyway, seems to have been working fine. The other relay I used for the new addition is a Zettler AZ43-1CH-12DE which should be able to do 12A at 125VAC and I believe I got those because they had similar characteristics on the coil as the original relay so that I would be able to use them much the same way.
Here is a link to page 3 of the timer circuit thread, probably half way down is more detailed info about the first relay.
http://www.picaxeforum.co.uk/showthread.php?t=16000&page=3

However, I know very little about transistors so please elaborate and comment on the appropriateness of the 2N2222 so I can learn.
 

techElder

Well-known member
I haven't had the time to look up data sheets on the relays that you mention, but just so you know ...

If you just quote the ratings for the relay contacts, you tell us nothing about the relay coil and what it takes to operate the coil.

Remember that a relay is an isolation product. There is no connection between the contacts and the coil.

So, if you need to know the appropriateness of a driver transistor for a relay, you need to specify the input requirements of the relay; not the output requirements.
 

TCLynx

Member
Sorry, I missed a number when I typed the model of the Zettler relay earlier.
It is AZ943-1CH-12DE and let me see if I can upload that data sheet.

And here is the info on the other relay from the other thread.
I just pulled out the meter and the relay that I couldn't find much info about.

On top it says 15A 125V so that seems to indicate that the contacts should handle the load I have planned for it.

The coil when I checked the resistance gave 322 ohms

When I hooked it to a 12VDC power supply and checked the current I got 44 mA
 

Attachments

Last edited:

TCLynx

Member
FYI, I've got this hooked up and it seems to be working so far. I think I should re-program to set a high temp feed cut off too but not to worried about that for a few months.

YAY it works! I think I need to order more sensors to make one for my big Aqupaonics system.

p.s. for anyone interested, I have a live Duck Cam running (I know totally off topic but some people might find it entertaining when it is light out. aquaponic-lynx-live-garden-cameras/duck-tv
 

TCLynx

Member
Ok if I want to edit my programing to only allow the feeder to operate between the temperatures of say 14 C and 31 C, how would I write that?

I also realized that I probably don't need the extra math in my code that I had before so things can get a bit simpler since I doubt I need to worry about the temp dropping to low? Or do I? It is possible the temp could get below 0 C but will this cause any issues if I simply want to operate the feeder when the temp is between 14 and 31?

Anyway, here is the proposed code.

Code:
  Symbol Temp_8 = B9
  Symbol Triplow = 14		
  Symbol Triphigh = 31 
   
Top:
      ReadTemp 4, Temp_8	' read the high 8 bits - approx temp in deg C

    ' respond to the temperature
    Temp_8 = Temp_8
    If Temp_8 >= Triplow Then Checkhigh
    If Temp_8 < Triplow then StopFeeder
    
Checkhigh:
    If Temp_8 > Triphigh then StopFeeder
    If Temp_8 <= Triphigh then OperateFeeder

OperateFeeder:
    Low 2
    Goto Timer

StopFeeder:
    High 2
    Goto Timer

Timer:
for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
    GoTo Top

Does it look like it will work?
 

John West

Senior Member
I checked the 2N2222 spec and it should work for your relays.

As far as your code, I'd suggest you pick each of the possible temperature scenarios you are checking for and go through your code with each one and see where it goes. I think you'll find you need to change it a bit.

I'd also suggest you put all of your subroutines outside of the working loop. It will make everything easier for you to follow.
 
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TCLynx

Member
I checked the 2N2222 spec and it should work for your relays.
I hope so since they seem to have been working. Been running the initial timer with one for a while now and had the sensor running for a few days now too.

As far as your code, I'd suggest you pick each of the possible temperature scenarios you are checking for and go through your code with each one and see where it goes. I think you'll find you need to change it a bit.
Well the original code seems to operate ok with just the single temperature trip point. I didn't get any errors when I ran this new code in the simulation.

I'd also suggest you put your subroutines outside of the working loop. It will make everything easier to follow.
do you have any examples to send me to look at? How I should be doing it? I just kinda search for what I'm trying to do or something close to go look at but I couldn't find anything so I decided to give it my best guess and see what people would recommend.
 

120ThingsIn20Years

Senior Member
[stuff deleted re subroutines]

do you have any examples to send me to look at? How I should be doing it? I just kinda search for what I'm trying to do or something close to go look at but I couldn't find anything so I decided to give it my best guess and see what people would recommend.
Did you sort this out in the end? If not here is an example of a gosub structure attached at the bottom . The { } are just to make the code collapsable if you use the PICAXE programmer (I use AXEpad for linux so they do nothing, but if you use them you can collapse your code and just show the main flow.

Collapsing all the code will show you the value of using gosubs because you can see the underlying simplicity of the program.

when you use a command like "High" its a lot like using a prebuilt subroutine.

I use gosubs for everything except decisions about which gosub to use, in the main flow area.

This means you can look at the code and see only the headings and the general flow without being distracted by how each of those parts work.

I make it a rule that a subroutine should only do one thing

I also make it a rule that if it does anything other than decide which subroutine to do next, it should be within the Main: and End: tags.

I find the decisions easier to follow if they are in the main flow area, but even they can be a gosub

ie gosub DecideToDoThisThingOrThatThing

So generally speaking

if it achieves something, put it into a gosub

if its an item on a list of things needing to be achieved, it should go in the main program area.

I start writing a program with some comments, and then debug it until it works :)

For the first minute of the life of a new program might look like this

Code:
Main:

     'gosub Initialise   

     Continue:

          gosub DoSomething 
          'gosub DoSomethingElse
          'gosub DoSomething         'use the same code again if you want which is sometimes a nice thing to be able to do
         
          'if something 
               'then gosub ToThis
               'else gosub ToThisOtherThing
          'endif

          'wait for a bit
          'check something

          'goto continue                        

End:

'-------------------------------

Initialise: '<-------- note the :
{
 'fill some variables and do some stuff that only needs to be done once at the beginning

return
}

'---------------------------

DoSomething:   
{
     'write all the code that does "DoSomething" here

return
}

'----------------------------

'etc etc
The rest of the code, the code that achieves things, is all under the End: line

each gosub sends the flow off to do that thing and the gosub ends with a "Return". Return sends the program flow back to the main program and goes to the next line.

This way if something breaks you can find the bit of code, and be faced with 20 lines of code rather 2000.

If the main program isnt flowing the way it should, that's also just a list of clear instructions thats very easy to follow and add to.

It also means it's very easy to comment out a stack of code by just commenting out the gosub line.
 

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TCLynx

Member
I must admit that I don't remember off hand.

This is the code saved as repeat cycle timer plus temp control relay
Code:
  Symbol Temp_8 = B9
  Symbol Triplow = 14		
  Symbol Triphigh = 31 
   
Top:
      ReadTemp 4, Temp_8	' read the high 8 bits - approx temp in deg C

    ' respond to the temperature
    Temp_8 = Temp_8
    If Temp_8 >= Triplow Then Checkhigh
    If Temp_8 < Triplow then StopFeeder
    
Checkhigh:
    If Temp_8 > Triphigh then StopFeeder
    If Temp_8 <= Triphigh then OperateFeeder

OperateFeeder:
    Low 2
    Goto Timer

StopFeeder:
    High 2
    Goto Timer

Timer:
for b1 = 1 to 9 
low 1
pause 60000 
next b1
high 1
for b2 = 1 to 2 
pause 30000 
next b2
    GoTo Top
The timer is only controlling the pump and it is operating separate from the temperature controlled relay which controls if the feeder turns on or not (the feeder timer is also separate) Not very elegant but it's working.
 

120ThingsIn20Years

Senior Member
I'm working on a fish activated lever system like I did in the past, but this time with a PICAXE to restrict the total number of feeds per day, and to restrict the time between each feed so they cant dump it all at once. I'll set up a LED near the lever (thanks SABorn) to indicate to the fish when they can feed to stop them tapping it when it wont work and they cant feed, and thus to re-enforce the response when they can.

Going with fish activation rather than temperature thresholds should gain the same result as far as restricting over feeding, but might allow for more feed if they are hungry in spite of being cold. Perhaps a combination of demand activation and temperature might give a good result.
 
Last edited:

Paix

Senior Member
Sounds like things are developing well.

if the readtemp command returns a value >127 then the temperature is negative, so X - 128 will give you the negative temperature. You might wish to do a test for this ahead of other temperature testing so that you can discard it as being below your lower threshold.

I can't see your pool getting into negative temperatures and you can ignore it if you wish, but at least be aware of it as you might one day change your code to sense in a situation where the temperature could be fairly high and very low. Best that you handle things right in that sort of situation. As you are it's unlikely to be needed unless you anticipate having to chip the fish out to feed them :)
 

TCLynx

Member
Thanks for the note on neg temperatures with the sensors seeing as it may be possible to use this idea of other projects. As for the fish feeding situation, it the temperature gets that high or low, no feeding should be going on. Actually fish probably not surviving anyway.
 
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