O yes, I removed it, anyway I cant test that cold yetOriginally Posted by skimask
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O yes, I removed it, anyway I cant test that cold yet
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No, but you can simulate it at the transmitter end with a loop instead of reading the temp sensor....duh!!!
Just set up the transmitter to send out a slowly changing temperature that goes up the scale, resets to the low end, climbs back up again, whatever works for you.
Or do it at the receiver end, put a couple of buttons in there, one button-temp goes up, another button-temp goes down.
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ok , I get that now,
I want to concentrate on the cold but not that cold part for now.. the sensor is sticking outsid now, its about -11C
I wanted to see what was behing calculated..
The 2's compliment, the binary value gives me a good degree (tempc)
when I put it in the equation it then screws up, I think the 2 byte count_per_c AND count_remain and different since it is in negative mode... hummm
Nothing is siad about this in the specsheet either, and the program on Rentron does not use that part.
here is the code:
Zerotemp: '------------- cases when zero celcius and positive Fahrenheit
temp1 = temperature
temperature = ( ~ temperature ) + 1 '----- do this later, right before displaying it
tempc =temperature
temperature = ((( temperature ) *100)- 25) + (((count_per_c - count_remain) * 100) / count_per_c)
tempF = ((temperature /5) * 9) + 3200
if tempF <= 0 then goto ZeroF
lcdout $FE,1, dec temp1 , ".", dec temperature ," ",$DF,"C"
lcdout $FE,$C0, dec temperature, dec tempc , ".", dec tempc/2 ," ",$DF,"F"
temperature," ",$DF,"C"
goto loop
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putting the 2,s compliment just befire works best:
but the temperature seems to cut in half,, showing -5C when it is -10C
Just getting +655 when I get to zero degrees.
loop:
'23
waitfor55:
serin portb.2 , n2400 , temp : if temp <> $55 then goto waitfor55
waitforaa:
serin portb.2 , n2400 , temp : if temp <> $aa then goto waitforaa
serin portb.2, n2400, encoded11.HighBYTE : serin portb.2, n2400, encoded11.LowBYTE
serin portb.2, n2400, encoded22.HighBYTE : serin portb.2, n2400, encoded22.LowBYTE
serin portb.2, n2400, encoded33.HighBYTE : serin portb.2, n2400, encoded33.LowBYTE
serin portb.2, n2400, encoded44.HighBYTE : serin portb.2, n2400, encoded44.LowBYTE
For counter=0 TO 7 'decoding
encoded1.0[counter]=encoded11.0[counter*2] : encoded2.0[counter]=encoded22.0[counter*2]
encoded3.0[counter]=encoded33.0[counter*2] : encoded4.0[counter]=encoded44.0[counter*2]
Next counter
'41
temperature= encoded1 ' putting back together as the original temperature
For counter=0 TO 7
temperature.0[counter+8]=encoded2.0[counter+8]
Next counter
temperature.LowBYTE = encoded1
temperature.HighBYTE = encoded2
count_remain = encoded3
count_per_c = encoded4
IF temperature.11 = 1 Then goto Zerotemp
temperature = ((( temperature >> 1) *100)- 25) + (((count_per_c - count_remain) * 100) / count_per_c)
tempF = (((temperature /5) *9 ) + 3200)
lcdout $FE,1, "TempC: ", "+", dec (temperature / 100) , ".", dec2 temperature," ",$DF,"C"
lcdout $FE,$C0, "TempF: ", "+", dec2 (tempF / 100) , ".", dec2 (tempF // 100)," ",$DF,"F"
goto loop
Zerotemp: '------------- cases when zero celcius and positive Fahrenheit
temp1 = temperature
temperature = ((( temperature >>1 ) *100)- 25) + (((count_per_c - count_remain) * 100) / count_per_c)
if tempF <= 0 then goto ZeroF
temperature = ( ~ temperature ) + 1 ': tempf = ( ~ tempF ) + 1 ' added this
tempF = 3200 - ((temperature /5) * 9)
lcdout $FE,1, "TempC: ", "-", dec (temperature / 100) , ".", dec2 temperature," ",$DF,"C"
lcdout $FE,$C0, "TempF: ", dec (tempF / 100) , ".", dec2 tempF ," ",$DF,"F"
goto loop
ZeroF: '---------------- cases when zero celcius and 0 Fahrenheit
tempF = 3200 - ((temperature /5) * 9)
lcdout $FE,1, "TempC: ", "-", dec (temperature / 100) , ".", dec2 temperature," ",$DF,"C"
lcdout $FE,$C0, "TempF: ", "-", dec (tempF / 100) , ".", dec2 tempF ," ",$DF,"F"
goto loop
end
Last edited by lerameur; - 30th December 2006 at 01:57.
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Why are you using:tempF = 3200 - ((temperature /5) * 9)
instead of tempF = ( ( ( temperature / 5 ) * 9 ) + 3200 ) ?
The positive case (the only one that's working) uses the +3200, the negative cases are using the 3200-.....
What's the deal there?
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simple I need to take the difference. I believe pic basic pro can only handle unsigned numbers. So but keeking the original forula we get negative number for zero temperature. So by putting the 3200 in front , we get a positive number and add a minus sign.
for -15 degrees celcius
we have 15*100 =1500 in the euqation
=3200 - (1500/5*9) = 500
= 500/100 ------divide by hundred caus ewe multiplied by a 100 initially
=5
= -5 ----- here we just add the minus
but anyway , remember when i said my decimal values was going reverse. I was thinking and that is similar from doing 2,s compliment . so i decided to do 2,s compliment on everything..
Zerotemp: '------------- cases when zero celcius and positive Fahrenheit
temperature = ( ~ temperature ) + 1
count_per_c = ( ~ count_per_c) + 1
count_remain= ( ~count_remain) + 1
temp1 = temperature
temperature = ((( temperature >>1 ) *100)- 25) + (((count_per_c - count_remain) * 100) / count_per_c)
if tempF <= 0 then goto ZeroF
': tempf = ( ~ tempF ) + 1 ' added this
tempF = (((temperature /5) *9 ) + 3200)
lcdout $FE,1, "TempC: ", "-", dec (temperature / 100) , ".", dec2 temperature," ",$DF,"C"
lcdout $FE,$C0, "TempF: ", dec (tempF / 100) , ".", dec2 tempF ," ",$DF,"F"
goto loop
ZeroF: '---------------- cases when zero celcius and 0 Fahrenheit
tempF = 3200 - ((temperature /5) * 9)
lcdout $FE,1, "TempC: ", "-", dec (temperature / 100) , ".", dec2 temperature," ",$DF,"C"
lcdout $FE,$C0, "TempF: ", "-", dec (tempF / 100) , ".", dec2 tempF ," ",$DF,"F"
goto loop
end
Last edited by lerameur; - 30th December 2006 at 18:35.
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I thought that would work, but nope
look at his thread, last couple of posts,
seems like I am not the only one having his problem .
Last edited by lerameur; - 30th December 2006 at 20:31.
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I'm thinking that the easiest way to solve this whole mess is to add an offset to the original C value.
The 1820 will only handle temps up to +85C and has an operating range of -55 -> +125C. So, that's a total range of 180C. So, add, say 200 to the original Celsius input. You still have 3 cases to deal with (+C/F , -C/+F and -C/-F), but it might be easier to deal with this way... (and it will still work in the confines of a word value, 200 + 125 = 325 , 20000 + 12500 = 32500).
At the receiving end,
If C temp is => 200 (20000) , then subtract 200 (20000) and handle it like normal, which already works fine. +C and +F
If the C temp is => 182.22 (18222) AND < 20000....handle it for -C and +F
If the C temp is < 182.22 (18222).....handle it for -C and -F.
In the last 2 cases when you have a negative temp, I think setting a display flag and converting the temp's to a positive range, then displaying them is the way to go (flip them back over the zero, i.e. -10 = 10 with a display flag), but you're already doing that (even though it isn't working at the moment).
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