Is this on the F84?
If so, What's your Pot and capacitor value?
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Is this on the F84?
If so, What's your Pot and capacitor value?
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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Yes, its with a F84A, with 10k resistor and a 0.1uF cap.Originally Posted by mister_e
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On wich pin? Hope it's not RA.4
Did you tried a higher capacitor valu.. let's say 1K
Is the MCLR pin tied to VCC with pull-up? if so wich value?
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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a 1K is tied to Vcc.
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Pot Diameter Size
I had a similar issue a while ago maybe I can be of some assistance.
I was also using the F84A, on PORTB with the POT command. I noticed that larger pots, over 15mm dia, read very clean, yet the small PCB mount types can be noisy, with values moving around, especially if they are the cheap and nasty 0.20c types.
When using small PCB types or small cheap pots,I compensate with software. I sometimes read 5 values, add together and get and average read, or other times I will read only even numbers and ignore the odd. It all depends what you need it for...
Also check your common GND and make sure your regulator can provide enough juice for the circuit. Are you using 78L05?
"Never under estimate the powers of an idiot"
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No, it's a NTE1960.
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Your regulator should be fine, rated at 1A...what are you feeding your regulator with? A wall type plugpack or a benchtop powersupply?
Yes, Sayzer also has a good idea.
I'm wondering whether you just have a bad Pot.
Have your tried buying another linear potentiometer?
I have at least 50 or so hanging around from equipment that has been scrapped :-)
Useful for many projects.
I throw in a MKT type capacitor and works well...
Even the cheap and nasty greencaps are ok
I also like using wire wound types, doesn't jitter much and provides a clean read, also normally quite low in resistance. U might need to add a resistor in series with it... and play around with the scale values.
what about your LCD display?
Start up pause?
are you clearing the display or just writing over old values?
I am acutally a little suprised, as there is really not much that can go wrong.
I assume you have a PIC 16F84A with the appropriate powersupply, a crystal...an LCD and POT attached with 2 wires and a cap. Right?
When you say it moves erratically, does it move 1 or 2 values up or down during idle? Or does it move in much bigger increments?
"Never under estimate the powers of an idiot"
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There is another way.
Use 1K POT with 100nF.
This way, you will get a large movement of the POT giving you softer reading max. "30" instead of 255.
You can then multiply this "30" by say 4 and have "120" as your POT reading value, still with soft reading movement. (multiply by 8 and get 240 could be another).
How is that now?
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