Frozen Feeder Stepper Connection

[NeonRabbit221B]

I am building a frozen fish feeder which will use a 5V stepper and peltier which I was hoping to connect to a L293D (just the stepper) and using the reef-pi dosing setup. Not sure how to do this as the stepper uses 4 pins to activate each coil. Would it be easier to just use an arduino for this so that the stepper rotates x angle every time it is powered on?

 

[Ranjib]

Yes. That will be easier. Reef-pi does not have stepper driver yet, which makes it little complicated.

 

[NeonRabbit221B]

I will update here with CAD files and program when I am done. Thanks!

 

[robsworld78]

Yes. That will be easier. Reef-pi does not have stepper driver yet, which makes it little complicated.

This is one of the things I get most asked about. I've looked a bit into it and I don't think it's that difficult on hardware or software side.

If a person uses a DRV8825 driver or similar they can connect it directly to Pi GPIO's.

The code should be easy as you only need to control the GPIO's and count the steps. Here's an example.

Raspberry Pi Stepper Motor Tutorial | Rototron

Dual rotating control panel MAME cabinet plus hobby projects and tutorials for Raspberry Pi, arcade and electronics.

www.rototron.info

 

[Ranjib]

This is one of the things I get most asked about. I've looked a bit into it and I don't think it's that difficult on hardware or software side.

If a person uses a DRV8825 driver or similar they can connect it directly to Pi GPIO's.

The code should be easy as you only need to control the GPIO's and count the steps. Here's an example.

Raspberry Pi Stepper Motor Tutorial | Rototron

Dual rotating control panel MAME cabinet plus hobby projects and tutorials for Raspberry Pi, arcade and electronics.

www.rototron.info

this will not require any changes in jacks/connector abstractions?

 

[robsworld78]

this will not require any changes in jacks/connector abstractions?

I don't think it should, just need to set a pin high/low for each pulse. Motors do have a variety of steps so there would need to be a setting for how many and one for speed, maybe steps per second. I don't think it needs a settings for driver step options as a person can set the pins Low / High using power or ground. Direction I guess some might like but not necessary either if that complicates things. Really just need one pin able to pulse. Like this I think it would be generic to any driver that works with Arduino/Pi.

Getting more complicated it sounds like PWM is better to use as the timing is more accurate but I don't how important that is for this application. As long as the steps are correct it shouldn't matter if speed is set to 150 steps per second but it takes +/- 5% of a second. I think all that matters is a pin can be set low/high over a period of time. Ideally it would be nice to use Jack or Outlet connector.

If you need to know anything about it I can try and get you an answer.

 

[Ranjib]

I don't think it should, just need to set a pin high/low for each pulse. Motors do have a variety of steps so there would need to be a setting for how many and one for speed, maybe steps per second. I don't think it needs a settings for driver step options as a person can set the pins Low / High using power or ground. Direction I guess some might like but not necessary either if that complicates things. Really just need one pin able to pulse. Like this I think it would be generic to any driver that works with Arduino/Pi.

Getting more complicated it sounds like PWM is better to use as the timing is more accurate but I don't how important that is for this application. As long as the steps are correct it shouldn't matter if speed is set to 150 steps per second but it takes +/- 5% of a second. I think all that matters is a pin can be set low/high over a period of time. Ideally it would be nice to use Jack or Outlet connector.

If you need to know anything about it I can try and get you an answer.

If pwm works then you should be able to already test this with stock reef-pi and pi pwm . Just by adjusting the frequency and duty cycle right ?

 

[robsworld78]

If pwm works then you should be able to already test this with stock reef-pi and pi pwm . Just by adjusting the frequency and duty cycle right ?

Yeah I suppose, it does sound like adjusting frequency and duty is what's needed. Not sure about the frequency range required though. Might that cause a problem on a pca9685 as changing the frequency affects all pins? Some lights flicker at wrong frequency.