Multiple Stepper Motor Control

[Charles.m]

Hi all. I am in need of some help and suggestions . I'd like to make my code more efficient and reduce the likelihood of errors. Specifically  i'd like  to know  how to create a simple algorithm in LabVIEW to control the steps and direction of my stepper motors. At present I am just repeating my code for each stepper in several states to control the same stepper but moving a  different number of steps and direction.  I have  one stepper that controls a pump mechanism hence the flow rate. One stepper that controls front/back motion of an sample injector block system. One stepper that controls up/down motion of the injector block. I am also using an Arduino Mega 2560 ( all the drivers etc and installed) .

[Eric_BOB]

Hi Charles

I have look your code , but i don't understand your process. Can you describe it step buy step if you want i help you.

Eric Bobillier (France)

[Charles.m]

Sure. The process is as follows:

1. First set the flow rate. Stepper number one will run at constant speed to mantain the pump flow rate at whatever the user inputs.

2. When prompted to sample

•        Stepper number two will move 'x' number os steps forward.

•       Stepper number three will then move 'y' number of steps forward

•       After a wait period stepper number three will move 'y' backwards and stepper number two will move backwards 'x' number of steps.

3. Stepper number one will run at constant speed to mantain the pump flow rate at the input value.

Charles

[Eric_BOB · Accepted solution]

Hi Charles

Here is my version, can you test it (i don't have arduino card at home) but i think it's ok. Take care i have modify pump pin numbers (show diagram).

Eric

[Charles.m]

Ok, so I am still going through your code but first things first... thank you for your help. I will post my feedback when  I test it .

[Eric_BOB]

My first release is buggy.

Here one another version who run better when you stop. Eric

[Charles.m]

I know its been a while but I am back again. I would like some help in modifying the current code to do the following.

1. Add a second pump (12vdc) to the stepper sequence.

2. Turn a fan on/off for five minute intervals.

3. Use a hall effect sensor to measure rpm and control pump speed.

The new step by step sequence is now as follows :

1. First set the  flow rate/ pump speed for stepper number one .

• Measure rpm using hall effect sensor and show the measurement on  a gauge. Use the measurement to adjust the pump speed . Stepper number one will run at constant speed to maintain the pump speed/ flow rate at whatever the user inputs.

2. When prompted to sample

•        Stepper number two will move 'x' number of steps forward.

•       Stepper number three will then move 'y' number of steps forward .

•       Turn on 12 vdc pump for 10s.

•       After a wait period stepper number three will move 'y' backwards and stepper number two will move backwards 'x' number of steps.

* There are 4 different sampling positions so stepper number two and three will move different steps each time the user hits sample.

3. Turn fan on/off for five minute intervals.

I have two questions. Firstly is there a better way to do the five minute intervals. In my current code I think the event structure will only read when there is  a value change ( sample button) instead of the specified time interval.  Secondly how do i incorporate the hall effect sensor measurement and control to the current code. I would appreciate any help before I butcher the code that was given to me.

Thanks in advance

Charles