Temp

[Joeroddis]

Will this simple program read the temperature ok and display it on the computer screen?
Will it be a value between 0 and 256? or and actual temperature?

Main:
readtemp 0,b0
pause 200
debug b0
pause 200
goto main

Cheers

 

[eclectic]

Joe.

First of all, which Picaxe are you using?

Then, have you set up the circuit EXACTLY as it is shown,
in Manual 2 page 128?

e.

 

[Joeroddis]

Ill be using an 18x, and i haven't built it yet, i was just wondering if the code looked ok?

 

[eclectic]

If everything is connected correctly, then the code should work.

Or, try

sertxd (#b0,cr,lf)

It will be easier to read.

And yes, it will output directly in degrees Celsius.

e.

 

[Joeroddis]

Ok, i will try that instead of the debug, thanks eclectic!

 

[mobents]

if it outputs directly to degrees celcius, how can it handle negative degrees? variable overflow?

 

[MORA99]

if it outputs directly to degrees celcius, how can it handle negative degrees? variable overflow?

You have to handle that in your own code, if the number is above 128 its negative (0 - (b0 - 128))

 

[Joeroddis]

All works my room is 27 degrees

And regarding the negative:

main:
readtemp 1,b1 ‘ read value into b1
if b1 > 127 then neg ‘ test for negative
serout 7,N2400,(#b1) ‘ transmit value to serial LCD
goto loop
neg:
let b1 = b1 - 128 ‘ adjust neg value
serout 7,N2400,(“-”) ‘ transmit negative symbol
serout 7,N2400,(#b1) ‘ transmit value to serial LCD
goto main

That is in manual 2, page 128

 

[eclectic]

Well done Joe.

You've sussed it!

Oh, and turn the heating down. You'll melt the Picaxe!

e

 

[westaust55]

Hi Joe,

If you wish to look at a greater resolution (tenths of a degree) then use the READTEMP12 command. You still need to handle the negative numbers with some extra maths but for temps above 0 deg C here is my basic code snippet:

READTEMP12, pin, w0

w0=w0*10/16

Degrees = w0 /10
Tenths  = w0//10

SEROUT pin, N2400 (“Temp = “,#degrees,”.”,#tenths)

you can change the last line of code to use the previously suggested SERTXD command.

 

[Joeroddis]

Ah thankyou westaust55 that looks interesting. When i get my circuit working ill be sure to add it in and give feedback!