# 10k Pots, and voltage outputs,

Hi,

I am controlling a stepper motor with my UNO, using a 10k pot to vary the speed of the motor.

All quite simple up to this stage.

Correct me if I’m wrong, but the 10k pot is supplied by the 5v and ground pins on the board, and the

center wire on the pot is connected to analogRead(A0) pin.

Is this value in volts?, because when I

connect a voltmeter between A0 pin and the same ground pin that the pot is using, I can get a reading

in volts.

This value is then mathematically converted to a number between 1 and 100.

All this I understand.

The whole project needs to be remote controlled, so I will use a standard, single direction, Electronic

Speed Controller (ESC)(which uses it’s own battery power), which does the same as the 10k pot,

If I use the same input pins on the ESC as the 10k pot, and put the positive, output of the ESC to pin

A0, and the negative to either of the 2 Gnd pins on the UNO, I will be very close to having it remote

controlled.

Have I got this idea going in the right direction, or am I heading for a blown-up UNO?

Hoping someone can give some input.

Thanks

Mick

Hi, Sorry your arrangement will not work.

Please draw a block diagram of how you want to connect everything?

The pot is a potential divider and as you have found you can adjust the voltage to A0 with it. If you look at your sketch that runs it, you will see that the arduino converts the 0 to 5V to 0 to 1023. This is then used by the stepper library to drive your stepper.

You say you want remote control, what do you mean?

Hi, what is your electronics, programming, arduino, hardware experience?

Tom..... :)

Hi Tom,

The ESC is is Mtronics, Tempo 15, which is a single direction only ESC.

The whole project is a radio controlled, model, rowing boat.

According to Tom Igoe, whose sketch I am basing mine on, the sketch converts the 0 to 5V from pin A0, to 0 to 1023, then to a value between 0 and 100, which "stepper h" then uses to control the speed of the motor.

I can put on a 50K pot, change the "1023" to "5440", and the system works, but the control is not as sensitive.

Why can't I use the ESC as a pot, (the value of which I am not sure of,) change the "1023" to the value of the ESC, and I'll be able to use the radio control to control the ESC and therefore the motor speed.

Thanks

Mick

Hi,

Mtronics, VIPER Tempo 15

How are you going to connect this, a motor controller, to a stepper motor? What is your "stepper", model etc. I'm still not sure how you want the arduino to be incorporated in this project. You say " remote" how, IR wireless, Please write out in POINT form what you want your boat to do and how you want to accomplish it.

You say you want remote control, what do you mean?

Hi, what is your electronics, programming, arduino, hardware experience?

Tom....... :)

MickyK: I can put on a 50K pot, change the "1023" to "5440", and the system works, but the control is not as sensitive.

Why did you pick 5440? The Arduino analogRead() can only read 0-5v. It actually doesn't matter what the value of the pot is because it's connected to 0v and 5v and the wiper can be any voltage in between.

MickyK: Why can't I use the ESC as a pot, (the value of which I am not sure of,) change the "1023" to the value of the ESC, and I'll be able to use the radio control to control the ESC and therefore the motor speed.

The reason why is the ESC is supposed to be driving a motor. If you connect anything else which is not a motor then your results will be undefined.

I think you want to use a stepper motor with radio control and you're trying to use an Arduino to accomplish that? The ESC is not necessary. The Arduino can decode the commands coming from the radio control by itself. I think the pulseIn() function will be very useful to you.