2 push buttons on a servo

mcm1822

Ive been trying to get a servo to operate using a push button to move it in the clockwise direction and a separate one to operate in the counter clockwise direction. the trick is that each time one of the buttons is pressed the servo will move 20 degrees and STOP, relative to the button pressed. there needs to be a total of 8 positions. Any help would be greatly appreciated.

Seairth

I suggest using a stepper motor instead of a servo.

mcm1822

Needs to be a servo. School project

Courtney Jacobs

Welcome to the forums, mcm1822.

As a general rule, we typically won't provide full code examples for students working on school assignments.

If you provide what code you've written so far and tell us where you are stuck then someone may be able to give you tips or assistance to get you moving in the right direction.

mcm1822

It's not for grade but I have 2 codes that are getting me in the right direction

First one:

Duration VAR Word
Duration = 750
PAUSE 1000

DO
IF IN = 1 THEN
IF duration > 500 THEN
duration = duration - 25
ENDIF
ENDIF

IF IN4 = 1 THEN
IF duration < 1000 THEN
duration = duration + 25
END IF
ENDIF

PULLOUT 14, duration
Pause 10
Loop

This causes the servo to respond to the push buttons but they don't stop at any particular point.

mcm1822

My second code causes the servo to rotate in increments but will not utilize push buttons and only rotates one direction

tomcrawford

Your first code doesn't stop because it keeps seeing the button pressed. You cannot press and release a button in so quickly. Set a flag when you first see a button and then wait for it to be released.

Genetix

Hello mcm1822,

Your program has a few errors that F7 (Check Syntax) will find.
1.) In the first IF...THEN, the IN is missing the pin number.
2.) The 2nd to last ENDIF is a one word command, not 2 separate words.
3.) The servo command is PulsOut, not PullOut.

A DO...LOOP will run forever until you remove the power or download another program.

Also, use the C icon on the posting toolbar to attach code so the formatting isn't mangled.

erco

What a great problem! How are you coming, mcm1822? Can you show a video of your setup in action?

tomcrawford

Genetix wrote: »

Hello mcm1822,

Your program has a few errors that F7 (Check Syntax) will find.

Since he described what the program did, I just assumed he had some typos when he entered it into the forum comment.

mcm, you can copy and paste your program. Stick it between the code markers you get when you press the C button on the format bar.

Courtney Jacobs

If you haven't already, you should read through Chapter #4, Activity #6 in What's A Microcontroller? for an overview of controlling servo positions with a pushbutton.