Turntable Control

[WarwickLaken]

I would like to move my turntable using a nema 17 stepper motor and an Arduino. I would like to move it CW/ACW with a potentiometer.

Sadly, being new to this I can't get my head round the sketch writing or understanding how to modifying existing sketches.

Does anyone have a sketch to simply slowly move my turntable?

Thank you

[ColinB]

  Firstly you don't say which turntable you are using. I assume it must be the Peco turntable. I would use a digital encoder instead of a potentiometer and use two digital input ports to read the signal ( it is a gray code). Sounds like an interesting project, sorry I cannot be of more help. The mechanical bit is the most difficult.

[96RAF]

There is a topic on RM Web forum about controlling a Peco TT and other projects using an Arduino. You may get your sketch over there.

https://www.rmweb.co.uk/community/index.php?/topic/82978-arduino-applications-and-programs/&tab=comments#comment-1366260

 

PS . I removed your earlier duplicate post on this subject. If you want to bump a post just reply to it saying ‘bump’ rather than repost the same thing because you had no immediate response.

[WarwickLaken]

Thanks for the input. I am using a Peco LK55 turntable as my Hornby turntable can't accommodate the number of tracks I want to use.

I have been on the RM website and still awaiting a reply from one of their contributors, I  have been directed to some other  site members but their projects are for me quite complicated and using DCC and home built electronics, not something I want to do Just yet. So still looking for this elusive sketch

Warwick

[96RAF]

...so still looking for this allusive sketch...

 

You will just have to read all of the pages on this ‘Peco TT using a Stepper Motor and Arduino Uno‘ thread as no doubt changes are made to the software as the topic progresses' but there is a basic sketch on the very first page.

 

https://www.rmweb.co.uk/community/index.php?/topic/78578-dcc-controlled-peco-turntable-project-using-a-arduino-uno/&tab=comments#comment-1223686

 

To be of more help I would have to build it for you.

[STG]

I have used a Raspbery Pi (similar to Arduino), to operate signals, which would be in a similar principle to a turntable. Here's how I would invisage it working:

- Depending on the current draw and minimum voltage supplied by the RPi / arduino, you may have to use a separate power supply for the motor, and use relays (this is what I use for 12v Signals, since the RPi can only supply 5v)

- You then have the choice of how you physically control the turntable / whatever, you have chosen a potentiometer.

- Ideally you'd have the arduino plugged into the relevant hardware, or if you're like me and want a main control panel on a different computer, you need to do a bit more programming. Here's how my system works:

The Raspberry Pi boots, activates a buzzer for 2 seconds, and then sends me a email, stating its local IP address so I can send it data packets. (If you don't want to add this email step, use nmap on a linux terminal to scan for devices on the network). The Raspberry PI in question runs on its own, no screen, the only interaction being through the python code. I then connect to it using a self-programmed app, and send it data such as `s,1,g`, which signifies Signal 1 should be set to aspect green, or if unavailable, red.

I'm not sure the specs on how a potentiometer connected a pin on the arduino would work - on a Raspberry Pi, the input is either detected or not detected, so you might only have the effect of two speed steps (ON/ OFF). I would imagine this would be an issue for slowspeed

 

Anyway, I hope this has helped and given people a few ideas. 

[ColinB]

Sounds like you are on top of the software bit, you need an analogue to digital input channel on the Arduino to process the potentiometer value, I am sure it must have one of these. Or as I said previously use a rotary encoder that outputs pulses on two diigital channels to tell you direction and speed, your software then has to effectively add or subtract pulses to give you a value, that is what is on the front of the Elite (2 of them in this case). So really the bit you want is how to mate the stepper motor to the turntable. I assume there are libraries of software on how to drive the stepper motor. 

[WarwickLaken]

Thank you all for the help.  I have read with great interest Tenders turntable, its helpful but more complicated than I want to go.

I have the turntable connected up. Its the software that I need, my efforts have seen the turntable going round like a propeller to shorts jumpy spurts, no happy medium.

[STG]

 

I have the turntable connected up. Its the software that I need, my efforts have seen the turntable going round like a propeller to shorts jumpy spurts, no happy medium.

We probably need to know how the whole device is connected to the arduino to help with the programming side.

If the turntable can be controlled via an output of the Arduino, if you know python, I recommend checking out the relevant GPIO Pins interface modules (which allow you to change the outputs, etc..) on pypi.python.org (Python package index).

I do know and have used Python for these purposes.