Please help with code for DS18B20

[malc-c]

Hi, Malc

You'll have to place your Button Key INSIDE the vivarium ( hé,hé ... WITH the snakes !!! ) if you want a true image of your temp.

Alain

Agreed,

I've just taken a further reading with the probes 2" from the heater, so its sampling the air temperature. Here's the result (the button logger still on the shelf as shown)



If you ignore the fluctuations in between 10pm and 3am when the snake was out and obviously laying on the sensor, and look at the period 4am to 4pm you'll see it a lot more stable and only has a 0.2C deviation.

DT, could you elaborate on a PID loop.

Alain, could you provide a link to that file... I'm frantically searching for a DS1820 so I can start developing this project, but as my PBP programming is so rusty (and basic) may need you guys to offer some assistance if I get stuck (or should that be when I get stuck )

[malc-c]

DT, could you elaborate on a PID loop.

OK - google was my friend

http://en.wikipedia.org/wiki/PID_controller

[malc-c]

Err.... yeah...

previous_error = 0
integral = 0
start:
error = setpoint - actual_position
integral = integral + (error*dt)
derivative = (error - previous_error)/dt
output = (Kp*error) + (Ki*integral) + (Kd*derivative)
previous_error = error
wait(dt)
goto start

LOL - £34 for a commercial thermostat looks more promising !

[Archangel]

Err.... yeah...



LOL - £34 for a commercial thermostat looks more promising !

What ? That's as clear as mud! I thought they taught you that in primary school.
34 pounds for a thermostat? Must be the VAT ! Damn Globalists, want to federalize the world !
http://www.prothermostats.com/produc...product=100934
$40 US 24.42 GBP

[astanapane]

hi all,

i would like to make the circuit for the thermostat. could you please upload the circuit schematic? thanks a lot for your help.

[astanapane]

Dear all,

sorry for asking you for the schematic, i did it from the code but i need your advice according to the second sensor please.

could you please help me out to finish the schematic?

thanks.

[astanapane]

i have been trying to simulate the circuit on the proteus and also trying to make it work on the test board.

On the simulation i have some result but on the test board i dont get anything on the lcd.

Unfortunately with the code from Elektor i get some results on the lcd on the test board. But very wrong result like 234 oC.

Could someone upload the hex file from Mr. Fratello's #35? Could anyone made it work?

[Darrel Taylor]

OK - google was my friend

http://en.wikipedia.org/wiki/PID_controller

You've got better friends than that.
HenrikOlsson for instance ...

PID-filter routine (2nd try).
http://www.picbasic.co.uk/forum/showthread.php?t=5874

I've used it. It works great.
It's a little tricky to find the correct constants. But trial and error usually works.
Although there is a purposeful method to tune the loop.
<br>

[malc-c]

You've got better friends than that.
HenrikOlsson for instance ...

PID-filter routine (2nd try).
http://www.picbasic.co.uk/forum/showthread.php?t=5874

I've used it. It works great.
It's a little tricky to find the correct constants. But trial and error usually works.
Although there is a purposeful method to tune the loop.
<br>

Sorry Darrel.... it's been a long day......!