Digital caliper remote display

I have a modified digital caliper fitted to my Myford tail stock.

The display on the caliper is difficult to read (eyes are not what they used to be) I would like to attach a remote display nothing fancy just to display the read out figures.

Any Ideas/suggestions?

I have a Arceurotrade 6" Digital readout bar with remote display.

The remote display is connected to the bar with a mini USB cable and contains two 3v battery.

I have a cable that will fit to the caliper and I can fit a mini USB plug.

Could this be modified for use with the display?

Ken

Hi Ken,

Why not just replace the digital caliper on the tail stock with the 6" readout bar which already has a remote display ?

Paul.

The answer is 'probably yes' - there are a small number of different protocols, but it is likely that the readout will work with both of them.

As long as you get the + and - on the right pins you won't cause any damage.

Neil

Hi Ken,

The answer is no, it won't work. The probability of the protocol being the same is rare. Also if you get the connections wrong, this will create further damage. Arc does not have protocol or connection information.

Google up yurystoys and visit his site for ideas. Arc does not warrant such products for alternate connections as suggested here, so any experiments you carry out would be at your own risk.

Ketan @ Arc.

But beware that some digital calipers use a USB socket to install firmware. The socket isn't necessarily wired to match the USB standard, and the caliper itself doesn't talk USB. There are also calipers/DROs that use USB plugs and sockets to talk to a proprietary display, but aren't compatible with anything else. And then, hurrah, there are Calipers that really are USB compatible. I think you need to read the specification to find out what you've got.

Dave

Hi All...

Ken Weeks said...

" I have a modified digital caliper fitted to my Myford tail stock.

The display on the caliper is difficult to read (eyes are not what they used to be) I would like to attach a remote display nothing fancy just to display the read out figures.

Any Ideas/suggestions? "

I made a simple DRO using an Arduino Nano and LCD display to show X&Y values from digital calipers, there is lots of information on the web available showing the Arduino programs although I couldn't find anything to show how to get 2 displays up at the same time so had to think about that one for a while....

Any reading can be reset to zero with the push buttons...the whole assembly is fitted in a 13Amp outlet socket and a blanking plate is used for the front panel..

rgds..Bob..

Thanks for all the replies.

Bob

Your reply is the sort of thing I am after but with a single axis.

Electronics is a bit of a closed book to me, I can assemble thing from a kit with point to point instructions but theory and programs enough said.

I have found a tutorial for connecting a caliper to an arduino uno but it gives the output to the USB port.

Any chance of more detail of you design?

Regards

Ken

Aha, fopund my pictures under Stub Mandrel:

Neil

Hi Ken...

I don't know about the Arc digital displays but it seems as if these products are made to be hack-use unfriendly on purpose..

As far as using an LCD display...yes certainly... a single axis reading should be easy enough, it is fairly straightforward to connect the calipers to wiring for the Arduino although if you wanted to have a remote reset to zero then the connection is more of a problem and probably best left alone... you can reset using the calipers button.

The main issues with connecting up to a remote display are ... setting up an LCD display...changing the voltage levels from the caliper to the Arduino...finding a program for the Arduino.. and fitting LCD and gubbins in a box, I use a 9v battery but make sure it's switched off when you finish..!

I will have to go and find the relevant information but will come back to you... in the meantime you will need to download the Arduino files to your pc.

It would help if you got a cheap Arduino Nano or any other Arduino to play about with.. these are available on ebay with the cable which connects your pc to it..

The voltage level changing I mentioned will require some soldering of two transistors and some resistors to a pcb... there are only 6 or so components so bear in mind that there is some hands on electronics required.

will be back....Bob...

Hi Ken...

the diagram below shows the main items and gives an overview of how they are connected up, I used an LCD with 'Serial' connection as this is a lot easier to wire up and program ... you can find them on ebay

One point I must address is that the dro unit gets all its instructions from the calipers and if the calipers are not adjusted within a few minutes then they switch off, consequently you can lose the position setting you had...but this is what happens normally with the calipers.

http://www.ebay.co.uk/itm/I2C-LCD-Display-1602-Blue-For-Arduino-Pic-Pi-/263112246526?hash=item3d42b644fe:g:cK0AAOSwvihY~Fh9

Will post the level shifter circuit next.

Overview diagram.. ...

Due to the success of this DRO used on my lathe, I have decided to make another for the milling machine... so will chart my progress..

I must add that the calipers I used are the cheap ~8inch variety which seem to produce the right data format for the program I use, BUT... I can't say that the same format will be the same with any others ! ... I have used the program on four sets of calipers now and they work perfectly well.

The Level shifter circuit as previously mentioned..below..

In Block Diagram I showed a 'low volts psu' this can be dispensed with if the battery is kept in the calipers; In my original design I used a separate supply as per the block diagram but found that a small capacitor about 33uF was needed to cut down on noise pickup which affected the readings.

The Box.

As mentioned I used a double mains outlet socket ... I found the MK modern style variety to be quite smart as it has a slight slope on the front... no I don't work for MK ... the material the box is made of is some sort of plastic and mills quite easily but does produce some dust, ...Wear A Mask ... some of the ribs inside the blanking plate need to milled off ... see pics.

About to be milled.

After milling out.

Well let me know if you want any more information.

rgds..Bob.

Hi Bob

Thanks for the posts,

Your suggestion about searching on line produced some interesting results.

I have invested in a book to give me an idea what the Arduino is all about.

Regards

Ken

Hi Ken..

now finished front panel apart from fitting Arduino and small pcb level shifter board... as below..

Above ^ the blue square is the lcd brightness control.

Have been doing some more work soldering the Arduino Nano and level shifting components on the pcb, this is done prior to fitting the pcb in the box, I am 'hot glueing' the LCD and veroboard pcb in place, it can be removed if necessary with a bit of heat .

I will be trying this set up using a caliper for the 'y' axis only ... I intend to use a rotary encoder for the 'x' axis, and as you are only interested in one axis display I won't be showing any of the rotary encoder workings.

pic below.... the pcb component side .. minus transistors...you may note I have two sets of components either side of the Arduino, this is initially for the two sets of level shifters ie, one for 'x' axis calipers and one for 'y' axis caliper.. for a single axis you obviously only need to have one set of these.

Below ... the other side but not yet cut the tracks .

Below...I cut out a slot to take the Arduino mini usb port and trial fitted the board.

So... its coming on... hope to have it up and running in a day or two...and let you see the program ... just hope all Arduino experts are not looking... but hey who cares ! ... so long as it does what it is supposed to do.

..Bob...

Like it Bob! Never thought of using a socket box to make a portable enclosure; that's a really good idea.

I've been inspired to stick an oscilloscope on my various digital calipers to see which, if any, are sending data. I can think of a few examples where having an external display on a caliper would be useful.

Dave

Edited By SillyOldDuffer on 04/08/2017 17:19:12

Hi Bob

Thanks for the posts.

As you suggested I have been doing more research on the W,W,W, and came across this site

DRO with Arduino and digital calipers by Scrachi - Thingiverse

He gives an concise explanation for making a 3 axis display c/w code using a Arduino Uno,

Another one I have found suggest using a Logic Level Shifter, 4-Channel, Bidirectional between the caliper and the Arduino Uno.,

With a bit of thought they could be combined to make a single axis read out and the code could be amended to suit

Regards

Ken

I see Chronos now sell a caliper with a Bluetooth connection built in - and wondered if this was a simpler way to do this kind of thing (straight to a phone app) ??

Regards,

IanT

Thanks Ken, Dave, Ian..

Yes Ian... I got an email advert this morning about the bluetooth connection app for a digital caliper... but could the idea be used in a 2 or 3 axis requirement..? .

The other thing is that I am actually only going to use one caliper on the Y axis on my milling machine as there is not much travel, however the X axis is quite long and I intend to use a rotary encoder which I purchased some time ago and am determined I am going to use it on something!

Anyway... the real reason is that I get such a feeling of satisfaction from doing things my own way and when it works and looks the part I am on cloud 9...!

Thanks for all your posts ... it is a real buzz to get appreciation.

Bob..

Might be the same one I bought that's sitting in a dollar-store box on a high shelf labelled "rotary encoder - don't throw out". I should really go back to that.