1

I'm following this tutorial page and I don't have a 10k ohm potentiometer on hand. Could I replace it with resistors to simulate a manual setting and replace the resistors to adjust to a new settings.

From what I was reading this pin is for contrast and I'm sure I could manually set the contrast once and be happy with it for quick prototyping. I'll be ordering a 10k ohm potentiometer on Monday.

3

Yes. All a potentiometer is, is two resistors end to end. The "wiper" is the join between the two resistors.

It doesn't matter too much what value potentiometer (and hence what value resistors) you use, as long as it's "around" the 10kΩ mark (100kΩ should be fine, 50kΩ, 1kΩ etc - anything below 1kΩ may not work) - what matters is the ratio of the values of the resistor.

  • Would this work + ---[10K]--[connection to wiper]--[100K]--- - – Tolure Feb 23 at 20:39
  • It may. It depends if that is the resistor ratio that you need. You will have to try it and see. If it's not right then change the resistors. But that arrangement of resistors is the right idea, yes. – Majenko Feb 23 at 22:33
1

Yes, you always can do that, depending on the resistors you have at hand, you can combine them to make e.g. 1 KOhm, 2 KOhm etc resistors.

Probably you need a linear potentiometer (which means halfway is 5 KOhm).

In a linear potentiometer, you can use the following resistance (made up by a single or a combination of resistors in series or parallel):

0

Yes, but you need only one resistor to GND. The display has already one resistor inside the display. I forgot what the value should be and I don't have a display at hand right now, so you have to try which value is best.

In most examples with a LCD display, a potentiometer is used for the contrast. Not many people know that only a (variable) resistor to GND is needed.

With a fixed resistor, you are not able to quickly adjust the display when the temperature changes.

  • If I'm just prototyping where the temperature doesn't change am I right to understand that I could simply go. [GND] ---- [Resistor] ---- [LCD Pin for contrast] – Tolure Feb 24 at 7:31
  • @Tolure, yes, correct, that is all that is needed to set the contrast. – Jot Feb 24 at 7:47

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