Arduinos and Microcontrollers ref: Rotary Table Mew 249

[John HaineParticipant @johnhaine32865]

Stepper motor vibration can I think occur when the stepping frequency is close to a natural resonance mode of the stepper rotor. Best way to prevent it is to change the stepping rate!

[JourneymanParticipant @journeyman]

I shall have to dive into the program and play with some of the constants to see if I can improve things. I have put my efforts to motorize a small Vertex table on my website Journeyman's Workshop if anyone is interested. If you find any errors (there are always errors) let me know and I will fix them

John

[Carl Wilson 4Participant @carlwilson4]

John,

Congratulations on a great write up. I did a very similar thing on my blog, British Reaction Research. Unfortunately space constraints within the magazine did not permit such a comprehensive treatment.

A very good idea to bring out the reset button and I shall modify mine forthwith!

Carl.

[JourneymanParticipant @journeyman]

Carl, many thanks. I had not discovered your blog previously, I wish I had! I have put a link to it on my web page, hope thats OK. Just as an aside I also thought about bringing out the USB connector to save keep having to take the lid off to re-program.

Cheers, John

[Carl Wilson 4Participant @carlwilson4]

Hi John,

Many thanks. I decided to leave the USB connector be. My unit worked as advertised straight away, so I don’t see a massive need for reprogramming. In the rare instance I might need to its no hassle opening the box.

Carl.

[Matt Homer 1Participant @matthomer1]

Another one having ago at the mew249 arduino project to run my rotary table.

I have looked at all the usual suspects blogs and forums but I cant get the stepper motor shaft to rotate.

makes all the right sounds but no shaft movement. Tried 3 different sketch stepper motor programs but all the same result.

Checked motor wires and researched that…tried another controller board but still no joy.

The only difference I can see is i am powering the UNO and LCD shield via the USB cable.

photo below.

Thanks Matt

[Carl Wilson 4Participant @carlwilson4]

Hi Matt,

For some reason I can’t see your photo. Can you post it again please?

[Matt Homer 1Participant @matthomer1]

I have added it as a photo/album…larger picture I think

cheers

Matt

[Matt Homer 1Participant @matthomer1]

On another point after I upload the version 23 stepper sketch file to the uno/lcd shield it all looks ok but the select button does not seem to act as it should on the you tube videos. I can through the different stpper functions but when you press select does not seem to goto another menu.

[SillyOldDufferModerator @sillyoldduffer]

Just a guess as I don't have Carl's article to hand but looking at the photo the ground connection between the Arduino and the Controller may be missing?

Probably red-herrings, I had similar symptoms by wiring the motor wrong (yours looks OK), and also after experimenting with the DIP switch settings. I have a different type of controller though.

On the select button, there's advice earlier in the thread that might help.  You may need to tweak the code.

Dave

 

Edited By SillyOldDuffer on 06/02/2017 21:36:46

[Roger Williams 2Participant @rogerwilliams2]

Matt, a couple of us had the same problem as you, so if you look back through these posts you will see that you haveto change the numbers for the SET figure in the sketch at the very bottom. I think I changed the setting to the same as Silly Old Duffers. Also Carl gives the correct settings for the Dip switches too .

Hope this helps.

[Matt Homer 1Participant @matthomer1]

Thanks guys will give it ago…found the silly old duffers sketch changes for the switches….cant find Carl's DIP switch settings though

[JourneymanParticipant @journeyman]

Matt, I agree with Dave it looks like there is no ground connection. This is my version of wiring up the bits…

Hope it helps, also double check the motor windings are correctly paired. It doesn't matter whether connected to A or B provided it is the right pairing they should also be in the same direction. Look at the motor specs for the colours.

John

Edited By Journeyman on 07/02/2017 11:13:38

[Matt Homer 1Participant @matthomer1]

Thanks John…where is the ground connection on the Shield.

looking at other peoples images I can see they have connected it just under the VIN lettering along with the 12v cable. Thought I might not need this been as power etc is coming from the USB lead for now.

PS have been following your diagram since I looked at your website again recently.

Matt

[Matt Homer 1Participant @matthomer1]

Managed to find something on the connector pin out…might be useful…Thanks Matt

[Carl Wilson 4Participant @carlwilson4]

Matt,

You will still need to ground the Arduino and driver so that the signals to the driver are referenced to a common point.

You can solder your ground directly to the Arduino on any of the ground pins or directly to the 0 volt pin of the power socket.

[JourneymanParticipant @journeyman]

Matt, I connected my power direct to the UNO there is a group of four pins [5v out],[Gnd],[Gnd],[Vin] in one group. If you go down the page on my website there is a link to the UNO pinout diagram. I am not sure it's a good idea to use two seperate power sources in normal use. I use the USB if re-programming (without the motor connected) but use just the 12v supply to run and test.

Cheers, John

Edited By Journeyman on 07/02/2017 13:04:24

[Matt Homer 1Participant @matthomer1]

nice one …thanks John

[john swift 1Participant @johnswift1]

Hi Matt

your wiring looks OK but you can do away with the USB cable by connecting the stepper drivers 12V supply to the ground and Vin terminals on the arduino

( the 5V regulator on the Arduino will drop the +12V down to +5V )

 

 

 

 

did you get the arduino to respond to the buttons correctly ?

from what I can see is the various manufactures don't stick to a single design for the boards they manufacture

and for the LCD / button shield the variations in resistor values in the button ladder results in changes being needed to the sketch

( note not all LCD + button shields can use PWM brightness control for the backlight !! )

see this posted by sillyoldDuffer

http://www.model-engineer.co.uk/forums/postings.asp?th=122792&p=4

,

I've been playing too and have a similar problem. I'm pretty sure the issue is the bit of code that works out which key is being pressed. It's the very last function at the end of the Sketch and it looks like this:

int read_LCD_button() // routine to read the LCD's buttons
{
int key_in;
delay(ADSettleTime); // wait to settle
key_in = analogRead(0); // read ADC once
delay(ADSettleTime); // wait to settle
// average values for my board were: 0, 144, 324, 505, 742
// add approx 100 to those values to set range

if (key_in > 850) return NO_KEY;
if (key_in < 70) return RIGHT_KEY;
if (key_in < 250) return UP_KEY;
if (key_in < 450) return DOWN_KEY;
if (key_in < 650) return LEFT_KEY;
if (key_in < 850) return SELECT_KEY;

}

 

the 4 switches that control  the motor current (SW1 to SW3 & S1) will need setting up fpr your motor

 

John

 

 

Edited By john swift 1 on 07/02/2017 18:31:45

[Matt Homer 1Participant @matthomer1]

Thanks John….wired the GND ok and used USB power as I couldn't get lcd display to power up after wiring to the VIN port.

Changed the code for the LCD buttons and hey presto life in the stepper motor..all worked.

Just tried wiring back the 12v to VIN and no power to display….dont know if I need to alter the voltage pot on the power supply ?

Thanks again guy's … see light at the end of the tunnel.

Matt

[JourneymanParticipant @journeyman]

Matt, have you got the Gnd (-12v) connection from the power supply to the UNO Gnd and to the TB6560?

John

[john swift 1Participant @johnswift1]

Hi Matt

with the 12V wired correctly to the arduino , I can't see any reason you would not have power to the display but

but I can see if the adjustment of voltage on the LCD pin 3 is set to a critical value

the display contrast could be OK when powered the USB cable when I'd expect +5V to the LCD pin 2 be nearer to 4.5Vdue to the voltdrop across a transistor on the arduino

( the transistor prevents the arduino trying to power your computers USB port !)

when powered by the arduino's 5V regulator when you apply 12V to Vin

the LCD (and arduino) will receive the full 5V possibly blanking out the display unless the multiturn potentiometer is adjusted

 

John

 

Edited By john swift 1 on 07/02/2017 19:01:59

[Matt Homer 1Participant @matthomer1]

sorry to be a pain…3 more photos uploaded in my albums of how it is wired now to PSU.

Did try the 12v and GND piggy backed off Controller board but same result no power to arduino and display unit unless I plug in the usb lead ( I disconnect the 12v lead from the LCD Display when I do this)

cheers

Matt

[JourneymanParticipant @journeyman]

Matt, Can't see anything untoward with the wiring in the photos. Is it just the display that doesnt work or is the UNO also unpowered? If the UNO is powered try the LCD contrast. Only other thing I can think of is bent pin between the shield and the UNO.

John

[Matt Homer 1Participant @matthomer1]

both uno and display have no power….resoldered pin and checked connections but still no good.

Will have another play tomorrow.

Thanks for all your replies and patience….newbie to this electronics stuff but great to see that motor rotate !

cheers

Matt

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