Re: files and PIC
Posted by
Alan Marconett KM6VV
on 2000-06-23 23:42:58 UTC
Hi Bill,
I haven't seen Briefcase. I'll look for it. Gotta do something!
You'll probably need to amplify the thermistor, or thermocouple. Check
out DALLAS Semiconductor, I think they have sensors with built in amps.
Other wise an instrumentation amp with low leakage/input current will
probably be required. Not really my area. With built-in A/D
conversion, the PIC's are great. I've not done anything with BASIC on a
PIC, although in the early 80's BC, (Before 'C') BASIC was the quick one
for writing test code.
You almost need PID control for a problem like that. Sort of like a
servo control. Proportional, Integral and Derivative signals keep you
from overshooting the temperature wanted. The J.R. Kerr Pic-servo
chipset sounds interesting, I'm wondering if they could be imployed to
control the temp. That output would be an analog signal. then your
"servo" could control the burner. Otherwise one would model PID in
software. You'll have to "tune" it, to get the plant to handle varying
loads without overshoot/undershoot. Quite a bit of thought to that
problem. Boiler temp and steam pressure.
Alan
I haven't seen Briefcase. I'll look for it. Gotta do something!
You'll probably need to amplify the thermistor, or thermocouple. Check
out DALLAS Semiconductor, I think they have sensors with built in amps.
Other wise an instrumentation amp with low leakage/input current will
probably be required. Not really my area. With built-in A/D
conversion, the PIC's are great. I've not done anything with BASIC on a
PIC, although in the early 80's BC, (Before 'C') BASIC was the quick one
for writing test code.
You almost need PID control for a problem like that. Sort of like a
servo control. Proportional, Integral and Derivative signals keep you
from overshooting the temperature wanted. The J.R. Kerr Pic-servo
chipset sounds interesting, I'm wondering if they could be imployed to
control the temp. That output would be an analog signal. then your
"servo" could control the burner. Otherwise one would model PID in
software. You'll have to "tune" it, to get the plant to handle varying
loads without overshoot/undershoot. Quite a bit of thought to that
problem. Boiler temp and steam pressure.
Alan
>WAnliker@... wrote:
>
> In a message dated 6/23/00 4:26:56 PM Mountain Daylight Time, KM6VV@...
> writes:
>
> << Now if I could just *MERGE* bookmark lists in Netscape
> 4.7 between my work (programming for a DOS-based, hand held automotive
> test computer: http://www.Interro.com), and home. >>
>
> When you figure it out, let me know. I am using windows 98, and there is a
> program called Briefcase, that I think will do what we want, but I have no
> idea at all how it works.
> I have a programmer that will do 16F84, plus a lot more.
> I want to measure the temperature in a boiler, and monitor the Steam
> temperature, and use this information to operate a servo to turn a valve off
> and on for the burner in a steam tug boat. I was thinking about a
> thermistor, and the pot command. Above a certain valve the burner receives
> an off operation of the servo, below the number it would operate the valve
> open with a servo operation. Unfortunately I have no idea how to do it, but
> doing some studying on it. I want to control the burner on a model steam
> boiler to maintain a steady pressure. I would probably have to use two
> different values to do the control, by comparing to the pot value, to get a
> high, low setpoint. I will be programing in the PIC Basic language, not C.
> bill