Using Numeric Input & Manipulating it

[gpw1057]

Hi all

I am trying to build a camera slider to timelapse my 3D printing.

Got it all set up to take a picture, when the print head parks after every layer.

What I want to do now, is to input the amount of layers in the 3D print say 320 using the keypad, then use that to alter the distance traveled by the stepper at each pulse so at the end of the print the slider is as the end.

I have a keyboard and LCD setup and working

Any help or pointers appreciated.

MB

[Paul_KD7HB]

@gpw1057

I have a keyboard and LCD setup and working

Then what is the problem? Just continue step by step.

[UKHeliBob]

Welcome to the forum

I am not sure what you need help with but if it is entering a number using the keypad then this might help

Keypad data entry. A beginners guide

A common problem raised in the forum is how to use a keypad to enter a number to be used in a sketch. The examples with the Keypad library show the principles but there is little or no explanation of how they work or how they can be changed The aim of this thread is to explain the principles of keypad entry, explain how and why some things work or don't work and to provide a way forward for more complicated use of the Keypad library Let's start with "How do I enter a number using the keypad ?" …

If you need help with something else then please give more details

[J-M-L]

@gpw1057

Got it all set up to take a picture, when the print head parks after every layer.

so you have a way to detect when the head is parked, which is what triggers taking a picture ?

@gpw1057

What I want to do now, is to input the amount of layers in the 3D print say 320 using the keypad, then use that to alter the distance traveled by the stepper at each pulse so at the end of the print the slider is as the end.

if your stepper starts at position 0 and needs to be at position endPos (in steps) at the end of the print, if you know there are layerCnt pictures to take then at layer number currentLayer you move the stepper to position currentLayer * endPos / layerCnt

[xfpd]

@gpw1057

Any help

int OneStep = TotalSteps / 320;

[gpw1057]

Thanks all for your help, I am just getting into this type of programming am so old, I used to quite happily program BBC basic, could do anything, just a matter of getting used to it, I am getting there, just needed some pointers, thanks

[J-M-L]

@xfpd

int OneStep = TotalSteps / 320;

If you calculate it once then you might fall short due to int truncation.

Say you need 800 steps, 800/320 =2,5 but will be truncated to 2 and int the end you’ll have done 320 x 2 =640 steps instead of 800.

That’s why keeping the full linear interpolation formula is better as you catch-up along the way.

[chanchaldada]

You can just calculate the distance per layer by dividing your total slider travel by the number of layers.

[PaulRB]

Please explain how the solution should involve LEDs and multiplexing.

[J-M-L]

@chanchaldada

by dividing your total slider travel by the number of layers

Mathematically this is correct but see post 7