Pulse proportional thermostat

[malc-c]

Alain,

The pdf is based on exercises using the basic stamp and discrete components for a to d conversion etc. Before I get my EasyPIC board out, what would be an ideal Microchip PIC to use ?

[Acetronics2]

Hi, Malc

relies on the sensors you use ...

LM 35, 335 .... ( voltage output ) will need 4 ADC Inputs ... Obvious, eh ?

DS 18x only need 4 Bidirectionnal I/Os ( Onewire "net" will lead to deal with DS IDs ... eh ! )

Add a nice 16 or 20 X 4 LCD ... say 1 full port

4 Pushbuttons or better a Keyboard ( looks more " pro " LOL ) 1 full port

4 R/G status Leds ... or 8 leds ... 1 Full port


let's "proto" aboard a 16F877A or 16F887 ... no soucy if a 28 pins is sufficient ( 876A or cheaper 886), and use of a faster or Bigger ROM ( if necessary ) 18F4520, 4620 or 2520/2620 will be easy ...

GLCD aren't so good, generally, because of the PID loops - BUT here there's no hurry for calculations ... or driven with it's own serial Pic Driver.

What about ???

Alain

[Charles Linquis]

Always use an 18F part if you aren't concerned about cents.

[jetpr]

I use LM358 read from 0c to 1000c and thermocouple type k
NumSamples CON 48
'ADCIN EGTChannel, EGTSample '0 to 255 EGT sample
EGT=0
EGTSample=0
For i = 0 TO NumSamples - 1
ADCIN EGTChannel, EGTSample
EGT = EGT + ((EGTSample * 255) / 60) 'The equation gives the actual Celcius reading
Pause 5
Next i 'Add it all into EGT.
EGT = EGT / NumSamples 'Divide EGT by the Number of samples