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Linear travel control

Posted by AndrewHallis 
Linear travel control
October 27, 2015 06:17AM
I need your help.
I have to control linear travel with optical enstop. I need to set the numer of motions (start-end) and set speed of the motions. For example: Do 20 motions (start-end) with speed 0,1m/s. I am completely amateur in this electronic. I'd like to control it only using LCD display with buttons (or rotations button - like LCD 2004). So I'd like it to be independent on the computer.

My question is: What things I need to create this project?

I have: - eptical endstop (3 pins) - can't see the model
- motor SX17-1005 (like Nema 17, 0,52 N.m, 4 pins)

The complete list of products what I need would be really helpfull (like: You need: driver(which one), arduino UNO, display, etc.), cause I have to buy these things till half November.

I found many circuits on the internet, but I am just confused. I think many of them are wrong.

Thank you for all advices.

Edited 2 time(s). Last edit at 10/27/2015 06:21AM by AndrewHallis.
Re: Linear travel control
October 27, 2015 11:56AM
Here we have discussed a similar question, maybe you can find some useful information there.
Re: Linear travel control
October 29, 2015 10:18AM
Can this circuit solve my problem?
Do I have to add some rezistors or something else?
The display has a controller H44780 and needs olny 2 pins to connect.
I am sorry I didn't translate it, but I think it's quite clear. winking smiley

Edited 2 time(s). Last edit at 10/29/2015 10:24AM by AndrewHallis.
Re: Linear travel control
October 29, 2015 12:44PM
It looks good, but I would choose a modern stepstick or pololu A4988 driver instead. It uses the same signals, so you only have to compare the pinout.
Re: Linear travel control
October 29, 2015 04:47PM
Do I need to use capacitor with A4988? Do I need use capacitor even with this EasyDriver? What capacity should I use? It's based on the power supply?
Re: Linear travel control
October 29, 2015 07:10PM
I tried to improve my circuit. winking smiley What do you think about this? winking smiley Is the capacitor chosen right? Any advice and opinion would be helpful. Again, sorry for not translating the notes, but I believe it's obvious.

Re: Linear travel control
October 30, 2015 03:44AM
I would try without capacitor. Usually the power supply is stable enough.

You should put MS1-MS3 to a certain level (5V or GND ) . Don't leave input pins "floating".
RESET and SLEEP are connected, but why? Or are they connected to 5V?
Re: Linear travel control
October 30, 2015 04:52AM
The RESET and SLEEP are connected together, because they have it here: [www.pololu.com]
And it's also discussed here: [forum.pololu.com] (1st reply)
Also, it looks like you aren't doing anything with the reset pin. You need to pull/drive it high to bring the board out of the reset state. One way to do this is to connect it to the adjacent sleep pin, as described on the product page and shown in the minimal wiring diagram
Something is also in datasheet, but I don't understand it much:
Reset Input (RESET). The RESET input sets the translator to a predefined Home state (shown in Figures 9 through 13), and turns off all of the FET outputs. All STEP inputs are ignored until the RESET input is set to high.

Sleep Mode (SLEEP). To minimize power consumption when the motor is not in use, this input disables much of the internal circuitry including the output FETs, current regulator, and charge pump. A logic low on the SLEEP pin puts the A4988 into Sleep mode. A logic high allows normal operation, as well as start-up (at which time the A4988 drives the motor to the Home microstep position). When emerging from Sleep mode, in order
to allow the charge pump to stabilize, provide a delay of 1 ms before issuing a Step command.

This picture is from Pololu website:

Like I said, I am not much familiar with electronics, I had to draw it like I saw it on the internet. :/
I have to admit, I don't know why are the RESET and SLEEP pins connected.
Re: Linear travel control
October 30, 2015 06:11AM
The Pololu driver module already has a pullup resistor on the /Sleep input. So connecting /Reset and /Sleep together is a simple way of ensuring that /Reset is held high too. Or you can connect /Reset to VDD.

The 100uF capacitor must be mounted close to the module, with short wires/leads.

If you do not connect the MS inputs to anything, it will do full steps, because they have internal; pulldown resistors.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
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