BS1 Pot Size

jeepguy_1980

I am setting up a BS1 and need to use a trimpot for an input. The manual states that the BS1 Pot function will "Read a 5 kΩ to 50 kΩ potentiometer, thermistor, photocell, or other variable resistance."

Does this mean that I can use any pot between 0-5kΩ and 0-50kΩ? Because I cannot find a pot that is sized from 5kΩ to 50kΩ.

sam_sam_sam

jeepguy_1980

As far as i know there are none i could be wrong

But what you could do is use a 50 k ohm· on the input of the pot put a 5 k ohm resistor and that would work
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"Read a 5 kΩ to 50 kΩ potentiometer, thermistor, photocell, or other variable resistance."

··You could used this to test these items with out have them
What you are aksing about


·(thermistor, photocell) (if you know what·vaules that they are )
················ The ones that you want to used·


·····················leads··········· leads······leads··············leads together
·················(·--(^--5 K ohm--^)

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(^--Pot 50 K ohm--^--^)----)




··················· I hope that you can understand what i have here

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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 9/27/2007 10:26:34 PM GMT

jeepguy_1980

I could but a 5k resistor in series. But, that will keep my design from being as "pretty" as it should be and it will render a percentage of my knob unusable, unless the board is capable of measuring beyond the 50k.

I'm really just trying to verify that I'm reading the manual correctly.

sam_sam_sam

jeepguy_1980

This will depend on the CAP that you use

If you only use a 50 k ohm the same thing will happen and if you are using a proto board the just put a 5 kohm·resistor·to the input of the Basic Stamp Input
and·have all you wire go to the board to the 50 K ohm·pot

I have done this before and it look alright but i know what you mean if you do not have to it that way it might make it look a little bit neater


I'm really just trying to verify that I'm reading the manual correctly.

You are but the lowest ohm value i can remeber what it is

It has been a while that i have used that code to use a pot

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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 9/27/2007 10:40:11 PM GMT

PJAllen

jeepguy,

Using the·POT command, you·can read a resistance up to 50K; as shown in PBASIC Help where·the potentiometer is wired as a rheostat (a variable resistor.)· Instead of a potentiometer/rheostat, you could use (substitute) resistors.

jeepguy_1980

I had considered using a rotary switch with different resistance values connected to each position, since I am only looking for 5 discernible values from my Pot. However, I want to minimize the Smile I have to solder to my board. I guess my best option for now is to put a 5k resistor in series with my pot.

PJAllen

???
You just don't get it.
Well, have fun with that.

jeepguy_1980

What is it I don't get? I don't know what "(substitute) resistors" are.

I do understand how the POT function works. The POT function does not read the resistance. It reads the time it takes for the 0.1uF capacitor to discharge below the threshold Voltage of the microprocessor (1.4V), which will vary based on the RC time constant of the POT circuit. The RC time constant will of course vary depending on the resistance to which the POT is set.