Project Help !! TFT, Hall Effect Sensor, and stepper duration.

Hello guys,

I’m currently working a project that I need a little help on it. I’m currently looking for suggestions and brainstorming. I think I have an idea how to get it all to work, but I need more info. There probably more then one way to achieve this, I’m just in limbo land at this point not being able to decide which way to go. Or maybe I’m wrong and I currently can’t achieve what I’m going after.

Current project is a Stepper that will run at 66 rpm for exactly 1 minute. Other things involved in the project is a 7inch TFT to press “start test buttons” and “reset button”. The button presses on the TFT will be CW START, CCW START, and RESET. There is also a hall effect sensor to display rpm to make sure the shaft is currently running at 66rpm. The stepper also needs to throttle up to 66 rpm. So I been looking at AccelStepper Library. I have used AccelStepper in the past on other projects using steppers. Just never used it in this type of application.

The hardware being used in this project are Nema 34, 13.5nm stepper, MA860H Microstep Driver, 350 watt power supply for the stepper , and sainsmart Hall effect sensor non latching for speed readout on the TFT. The arduino is a DUE.

Currently I have done research on

http://gammon.com.au/interrupts

http://forum.arduino.cc/index.php?topic=223286.msg1618246#msg1618246 = Demonstration code for

several things at the same time.

I know most hall effect sensors are used in conjunction with ISR, but I don’t know how that is going to effect the stepper output or speed. I currently have all the UI elements designed in a function that is called once in the beginning and that is about as far as I am. Please any feedback would be great.

Thank you,

Ryan

There is also a hall effect sensor to display rpm to make sure the shaft is currently running at 66rpm.

That's an unusual way to use a stepper. Normally, you'd have a home-sensor (or sometimes two limit-sensors) to find the starting position and then you trust the motor to take a step every time it's supposed to. (You can count the steps back to home to make sure you haven't lost any steps.) Normally, you'd find home at power-on/reset. Or if it's some kind of cycling operation, at the beginning of each cycle.

Or, there may be some applications where you don't care about a particular starting position and you don't need a home sensor.

66 rpm with acc/de-acc is not going to give you 66 revs in “exactly one minute”.

Hello,

I don't need to achieve 66rpm in exactly one minute. The shaft just needs to be running at 66 rpm at that speed for one minute. Then the test needs to shut off. Its a test bench being built for lead testing. Its to measure micro grooves on cylinder surfaces after surface grinding from the machine shop.

The areas I need help with are Capturing rpm, running the stepper, and stopping the stepper after one minute has elapsed. After the test has stopped there is some manual measurements that need to be taken from the shaft.

The area I need to be pointed in the right direction involves running the stepper, taking hall effect sensor input, and outputting that information to the screen. I can easily do all of these things by themselves, I just don't know where to start to have this all being done at the same time.

Thank you,

Ryan