Connecting a pot
I'm working my way through Parrallax's Board of Education series, "What's A
Microcontroller?"
I have had no luck with either of the two experiments involving
potentiometers.
I'm currently stuck on Experiment #5, "Measuring an Input"
The text reads:
"As you¹re connecting the potentiometer, you¹ll notice that there are three
terminals or connections available. One of these is the ³wiper² and the
other two are the ends of the resistive element. We only need to connect one
end and the wiper contact to our circuit, as shown in Figure 5.2."
I'm new to reading schematics, but doesn't the illustration show all three
leads to the pot being connected, not just two?
I've attached a copy of Figure 5.2 (I compressed it down to a tiny web file,
4k, I hope that's acceptable in this forum).
Looks to me like one end lead is attached to Vdd, the other end lead to a 1k
resistor, and the wiper attached to Vdd as well.
Doesn't make sense to me, and the experiment doesn't do what it should.
Clarification anyone?
Thanks
Microcontroller?"
I have had no luck with either of the two experiments involving
potentiometers.
I'm currently stuck on Experiment #5, "Measuring an Input"
The text reads:
"As you¹re connecting the potentiometer, you¹ll notice that there are three
terminals or connections available. One of these is the ³wiper² and the
other two are the ends of the resistive element. We only need to connect one
end and the wiper contact to our circuit, as shown in Figure 5.2."
I'm new to reading schematics, but doesn't the illustration show all three
leads to the pot being connected, not just two?
I've attached a copy of Figure 5.2 (I compressed it down to a tiny web file,
4k, I hope that's acceptable in this forum).
Looks to me like one end lead is attached to Vdd, the other end lead to a 1k
resistor, and the wiper attached to Vdd as well.
Doesn't make sense to me, and the experiment doesn't do what it should.
Clarification anyone?
Thanks
Comments
Notice in the diagram that both the wiper and the top end of the pot are
connected to the supply voltage. That amounts to a short across the top part of
the pot.
You could leave the top part of the pot disconnected and it wouldn't have any
effect. The schematic is in error.
Good luck.
Tom O'Brien