LCD Display

[blueroomelectronics]

Depends on what temperature range you want to read as far as the diodes are concerned. As for the DS18S20 they're great little ICs, you can network them on a single 3 conductor cable. There is a DS18S20-PAR which works with a 2 wire cable too.
Yes many PICs have a pair of comparators which would work fine with an analog sensor like the LM34/35
The EasyPIC5 is popular and IMO kind of overkill, take a peek at the Junebug threads here; it has a 1-wire sensor socket on the front. It's also got an MPLAB compatible programmer / debugger and 18F tutor onboard.
And I'd recommend looking at Swordfish BASIC the free SE version can do all the things you're looking for.
PS I'll throw in a free ROBIN PCB (small LCD device that might just be what you're looking for) if you buy a Junebug

PS you probably don't want a GLCD display (like you described) but a 20x4 character display can do block graphics.
**broken link removed**

 

[Salgat]

I personally have found the AVR line of micros to be the easiest to program. The flexibility it offers (32 registers allowing for many programs to never touch RAM) and the universal instruction set are very nice. (I learned how to program an AVR with most of the features in roughly a week).

 

[Super_voip]

If you were to use digital temp sensors, DS18S20, LM74 or LM75 for example, the signal conditioning circuitry needed for the analog sensors can be eliminated and as you are using this in an auto this can be a big advantage.

 

[karenhornby]

If you were to use digital temp sensors, DS18S20, LM74 or LM75 for example, the signal conditioning circuitry needed for the analog sensors can be eliminated and as you are using this in an auto this can be a big advantage.

Thanks for that info, Its one of the things I was wondering, but how exactly would you connect the sensors to the PIC?

Sorry I've no experience at all with digital temp sensors like the DS18S20 and the LM74/75 and no idea at all about how I2C Bus interface works, I'm only just starting to get interested in Digital stuff.

Would each sensor go to a different input? and how could you monitor the temp, and trigger an output once a specific temp was reached or went higher than the temp needed?

 

[Super_voip]

All the digital sensors would use 1 or 2 pins, they are connected in parallel and each has its own address. There are plenty of examples on the web, most with code, on how to connect. The micro reads the temp of each sensor and once it has exceeded the trigger point then messages or alarms can be sent.

 

[karenhornby]

All the digital sensors would use 1 or 2 pins, they are connected in parallel and each has its own address. There are plenty of examples on the web, most with code, on how to connect. The micro reads the temp of each sensor and once it has exceeded the trigger point then messages or alarms can be sent.

Thank you, that has cleared a lot up for me
now "ALL" i have to do, is learn how to program a pic, and figure out how to drive external relays from the outputs, and also drive a display module

Lots of reading/studying

 

[Super_voip]

Most of the code is floating around and there are BASIC packages around with all these drivers built in, the PIC programmer is simple, in fact so simple I didn't realise I had one and bought a second (much nicer, flashing lights) one.

 

[karenhornby]

Most of the code is floating around and there are BASIC packages around with all these drivers built in, the PIC programmer is simple, in fact so simple I didn't realise I had one and bought a second (much nicer, flashing lights) one.

Would I be right in assuming that you mean there is code "floating around" that will do the same or similar to what I've said I need it to do in the 7th post above this? All i'd need is to find this code and modify it for my purpose? All i'd have to do is how to interface the external circuits to the PIC?
any idea what to look for if I tried to search for code?
Sorry for all the question, but like I said I know NOTHING at all about digital electronics so far, but I HAVE used a programmer back in the late 90's when I used to watch satellite from abroad and had to program "smart cards" to decode the various channels, however all I did was use readily available (then) bin or hex files but i dont even have that programmer these days (yet)