Backyard Aquaponics
A place to discuss aquaponics

Due to increasingly strict luggage weight restrictions, one of very very few books that I brought with me from the UK

cool, I don't even have a copy...

I have had mine for a few years now.

about page 79

Looks like some basic theory on opamps...

resevs - your desk is much tidier than mine !

I have a lock on the door of the workshop/computer room.
Not to keep out would be thieves, but to keep the missus out.
Would be a disaster if she started tidying up in here

I'm downloading the book.

You should have seen it a few hours before that photo was taken! We have just moved house and this was the last room to get sorted. You couldnt even see what colour the desk was.

I think i am going to have to close the door. It seems the kitten has taken a liking to my multimeter. My GF doesnt even bother with my 'underground lair' (*<-- said in a dr evil voice).

That is one of the pages i read Super. Some times when im reading these books i end up having google there as well to try and understand some of the words. lol

Anyway turns out i was having a brain fart and forgot that the picaxe im using has a 10 bit ADC so i didnt even need an opamp. Reading directly from it has about 0.5 degree resolution i think. A quick google found some picaxe code i could copy and paste and it seems to be reading within a degree of the ds18b20. I also found that the resistor i was using for the current through the LM335 was a bit high. Got a colour back to front. It has been a while.

I looked at the datasheet for the LM335 again.
Its output is 10mV/Kelvin where as the LM35 is 10mV/C
25C is 298K - so 2.98V at the output - no need to amplify (which is nice)
A 10-bit AtoD will resolve to about 4.88mV (Assuming VDD is 5V) - so yeah, about 0.5K resolution.

Thats the one Currently the ds18b20 is at 31deg c and the lm335 is 30.9deg c.

Please dont post up anything in the forum that isnt public domain it would make us all look bad.

That Dallas One Wire thermometer makes live much easier if interfacing with micros.
Did made a dual temp. meter a while ago but as soon as I showed it off, DS18B20 dual thermometer, somebody found cheaper ones
to be had in a H/Ware store.B’s Thermometres

Was experimenting with the LM35, using the read and inverted value to adjust pump “TimeOFF” period on the AP Controller
but didn’t find it really necessary so didn’t implement it.

No intention of posting it in the forum

Oh, what one, for the dual DS18B20, just click on the link,
The LM35 wasn’t implemented and as the AP controller is made for my particular setup,
it wouldn’t be really of much use.