# New (soon to be) TouchDRO user.



## sdavilla (Jan 19, 2022)

Finally decided what to do about a DRO. I have a PM30-MV inbound. Eventually I'll CNC it. Figured, what the heck, I'll save on the PM DROs and get some glass sides.  Vevor Linear glass scales, 5um. Wanted magnetic but those are overkill for the PM30-MV and much more expensive. So $166 for three-axis, 600mm, 400mm and 250m and $109 for the TouchDRO box. The TouchDRO is due in tomorrow, scales on Sat. I have several android tablets floating around from past projects.

One scale came in early today so now we prep for play time. First to verify the pinout and check the signals. And yes, that's a backhoe (485) boom. The other end is a JD4500 with 460 loader.







It should match this from their website.






TouchDRO is interesting. Might take a stab at diving into private bluetooth API's on iOS to see if I can get comm. While I have android things around, they are strictly controlled (don't trust them much), I prefer iOS. Personal choice. It might pop up on OSX too.


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## buffdan (Jan 19, 2022)

Looking forward  to seeing the progress on this install. Thanks for sharing


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## ycroosh (Jan 19, 2022)

I looked into iOS but it's a full stop no-go for me. Apple restricts almost all BlueTooth profiles very tightly. SPP (RFCOMM) is locked down and in order to get access the device must have a special Apple security chip (that you can only buy from them, of course), you need to get into their hardware developer program, and there are all sorts of conditions and money involved. Basically, unless you are planning to make tens of thousands of something, Apple is not feasible. Not even talking about the hoops one needs to jump through to get an app to their App Store. 
A "hacky" approach is to use HID profile (i.e. pretend that TouchDRO is a mouse or a keyboard), but that is a very bad idea since there is no way you can route it to only one set of inputs.
OSX is Unix, and I don't think there are any technical issues there. My main laptop is a MacBook Pro and I do almost all of the testing on it. Not sure what one would need to do to get the app signed, though. Probably not cheap...
I get your concern about Android, but in practice, Apple is more secure only because it's more locked down by default. Once you enable unsigned apps, start sideloading things, etc., one isn't any better than the other. Sounds like you know at least something about security, so I don't see a reason you won't be able to lock down an Android tablet. (worst case - disable WiFi). Oh, and don't buy off-brand Chinese stuff...
Regards
Yuriy


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## sdavilla (Jan 19, 2022)

And a lovely unix it is.  

I've been an Apple Developer for decades with a few paid apps still up for iOS and tvOS. It's always fun to submit an update.  Never know what will happen, sometimes smooth sailing and it gets approved and posted in a few hours, sometimes days. Not done an Apple Store OSX app yet but the submission process is similar. Signing is just like for iOS/tvOS. Also have developed apps for Google and Amazon. Even built custom android firmware a while back. Now that was fun and games.

Only real problem we ever had was in the early days of tvOS and getting a ton of dynamic libs into the right place in the app. Spent weeks going round and round, getting 1st level rejection which is a bot that scanned the app for various things like private API usage. Eventually figured it out and never hit a 1st level rejection again.

Anyway, this should be a fun project and we will see where it goes.


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## ycroosh (Jan 19, 2022)

Ah, looks like it's $100 per year to get an Apple developer account, and then you can get a cert. That's not too bad. I guess I'm still traumatized by MS driver signing process


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## sdavilla (Jan 21, 2022)

Haha, another scale came in today, with the "shipment" showing tomorrow. Go figure.

The test setup, wire up an DB9 with matching pins (their diagram was correct),






Pulls 0.07 amps at 5V,






And the A/B signal looks like this,






Did one run that gave me 17.9kHz pulse cycle by sliding the encoder fast. So maybe 20kHz max. Next is find where R1 is located on the scale, center or either end.  Last is position/step test. Specs say 5um. I can measure that 

Going to attach with spherical washers to deal with any surface issues. Expensive things.


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## sdavilla (Jan 21, 2022)

Wow, just did a dynamic run that showed 250kHz...


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## ycroosh (Jan 21, 2022)

So I'm slightly confused - what problem are you trying to solve? 
Also, why do you think you need spherical washers?


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## sdavilla (Jan 22, 2022)

No problems, just getting an idea of the real-world capabilities of these glass linear scales. I'm an old school hardware/software guy and never diddled about with linear glass scales. They are interesting and I want to know how they work and more important, how well they work. I've got the test equipment which makes probing and testing easy.

The spherical washers are an attempt at dealing with the sloped sides of the pm30mv for the x-axis. Rather than some complex mounting brackets, the spherical washers might give me enough angle for alignment. Really have to wait for the pm30mv to arrive and take some measurements. 

Also found a working amazon tablet. That missing piece solved.


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## sdavilla (Jan 22, 2022)

Easy side-load of TouchDRO to the Amazon Fire Tablet. 

This will fetch the apk, and generate a QR code that contains the URL. Grab a free QR code reader and enable side-loading, read the QR code and it will fetch the apk. Simple.






Up and running in a few mins. This is a Fire 10, 5th gen. The o-scope tap is on R1, seems to never change from GND. Humm.






Enclosure assembly time.







Shows up in OSX bluetooth (macbook pro) and after pairing, we get a device that we can dump. Nice. Is the API available ?


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## sdavilla (Jan 22, 2022)

Oh and you can see from above, third axis came in today.


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## sdavilla (Jan 22, 2022)

Sneaky, sneaky. This one step in x.







Which results in 0.001 inch as far as my crappy dial indicator and shaky hand. I swear, go past 60 and all sorts of things start happening.






So one "step" is 25.4 microns, from an advertised 5 micron glass scale. Humm, could mean the line spacing is 5 um, maybe. Oh google...


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## sdavilla (Jan 22, 2022)

D'uh, read the manual, sparky  Got to calibrate first...


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## ycroosh (Jan 23, 2022)

sdavilla said:


> No problems, just getting an idea of the real-world capabilities of these glass linear scales. I'm an old school hardware/software guy and never diddled about with linear glass scales. They are interesting and I want to know how they work and more important, how well they work. I've got the test equipment which makes probing and testing easy.
> 
> The spherical washers are an attempt at dealing with the sloped sides of the pm30mv for the x-axis. Rather than some complex mounting brackets, the spherical washers might give me enough angle for alignment. Really have to wait for the pm30mv to arrive and take some measurements.
> 
> Also found a working amazon tablet. That missing piece solved.


Got it. I thought something was not working and you were troubleshooting it.
Glass scales can tolerate some misalignment (the carriage is decoupled from the external case). On my mill, I 3D printed a pair of wedges finally, but for years the scale was crooked by about 3-5 degrees. I guess spherical washers is the "grownup" way to solve this


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## ycroosh (Jan 23, 2022)

sdavilla said:


> D'uh, read the manual, sparky  Got to calibrate first...


This weekend I'm working on a "getting started" page to be included in the box. Many people don't realize that the DRO needs to be calibrated. Your reaction is the most common, but about once in a while, I get "YOU SUCK!!!! YOUR DRO SUCKS!!!! The f...ing thing is showing wrong numbers. I moved the scale by 0.1 inches and it's reading .25. Never touching this POS again." (this is a verbatim quote from a Facebook message I got this Thursday.
I wonder if it's better to have a printed page with instructions, or a QR code/link to a video.


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## Navy Chief (Jan 23, 2022)

ycroosh said:


> This weekend I'm working on a "getting started" page to be included in the box. Many people don't realize that the DRO needs to be calibrated. Your reaction is the most common, but about once in a while, I get "YOU SUCK!!!! YOUR DRO SUCKS!!!! The f...ing thing is showing wrong numbers. I moved the scale by 0.1 inches and it's reading .25. Never touching this POS again." (this is a verbatim quote from a Facebook message I got this Thursday.
> I wonder if it's better to have a printed page with instructions, or a QR code/link to a video.


I would go belt and suspenders, include the printed page of getting started instructions that has a QR code to the video. 

Sent from my Pixel 5 using Tapatalk


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## sdavilla (Jan 23, 2022)

Haha, I should have stopped assembling the enclosure. The super glue I used was old, in the freezer for god knows how long. Still liquid so I pressed on. Took about a day to fully cure but ended up butchering the assembly with super glue all over it. Useable but looks like crap,  lol. Lesson learned.

I looked and there was no option to order a replacement enclosure as this one needs some serious sanding on the outside.


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## sdavilla (Jan 23, 2022)

Let's see, 
5um == 0.00019685"
1/0.00019685 = 5080.010160020320041
so using 5080 CPI as calibration, now I get 0.001" on the TouchDRO display and 0.001" on the dial indicator. Easy-peasy.

So these are really 5um scales, as advertised. Sweet. No fuss, no mess (besides the enclosure). 

Seems to persist over power cycle too. I get  x5;y0;z0;w0; for a 0.001" move. That's about right. Nice.


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## sdavilla (Jan 23, 2022)

Forgot to show the setup for measuring. Ok for a quick setup/test but I'll repeat once the mill gets here. This is way too wiggly for serious measurements.


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## sdavilla (Jan 23, 2022)

PCB installed in enclosure.






Nice, btsnoop over net works in wireshark.


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## sdavilla (Jan 23, 2022)

These Vevor glass scales have double seals that look to be close to 100 percent sealing. I'm wondering if anyone is running a double seal scales without chip cover ?

Seems to me with the scale mounted with encoder down, it would be very difficult for any dust/shavings to enter. Would make mounting easier by excluding the chip cover.


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## sdavilla (Jan 26, 2022)

Wow, did not expect those results. (y-axis)  







The setup,






Two 2-3-4 blocks with a socket bolt in the encoder.  Set zero on left block, slide encoder right and slip the other 2-3-4 block in, slide encoder back. Talk about a loosey goosey setup.


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## sdavilla (Mar 5, 2022)

X-axis mostly finished.


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## sdavilla (Mar 30, 2022)

Finished the install.






Left side






Right side






Button head hex screws makes for a clean look too 

I will have to say, very pleased with this install and TouchDRO works like a champ. Under $300 for everything.


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## OldFatMan (Mar 31, 2022)

Thanks for the write up. Had about decided on TouchDRO for my mill/drill but you just drove in the proverbial last nail. Will be ordering x and y scales and adapter soon.


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## sdavilla (Apr 2, 2022)

Finally mounted TouchDRO controller. Was bouncing around trying to decide where it should live. Back of table, under table, on monitor arm. Got tired of moving it around and stuck it on the back of column. 






Battery backup/power supply goes under table, on back panel. There's already a 24 inch, 8 outlet Tripp Lite AC outlet strip mounted there.


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## Brento (Apr 2, 2022)

sdavilla said:


> These Vevor glass scales have double seals that look to be close to 100 percent sealing. I'm wondering if anyone is running a double seal scales without chip cover ?
> 
> Seems to me with the scale mounted with encoder down, it would be very difficult for any dust/shavings to enter. Would make mounting easier by excluding the chip cover.


I pretty much have the same scales I believe as far as covers. I just have a ToAuto DRO. As of now i dont think i will be using the covers bc of spacing and as you said with them upside down it will make it even harder to get swarf in it. I dont use compressed air just a brush and one or those little air bulb squeezer things.

GearFend Dust Cleaner Strong... https://www.amazon.com/dp/B087NHW5FZ?ref=ppx_pop_mob_ap_share


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## JFL4066 (Apr 4, 2022)

Is that a custom made IPad holder/arm? Or did you buy it?

A very nice setup!


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## sdavilla (Apr 6, 2022)

JFL4066 said:


> Is that a custom made IPad holder/arm? Or did you buy it?
> 
> A very nice setup!



An old VESA monitor mount + new VESA iPad/tablet holder. Replaced the short 6" arm with a 12" arm. And added grub screws to mount to keep it from swinging.


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## sdavilla (Apr 6, 2022)

More details:

OmniMount - LCD Monitor Cantilever Mount -> https://www.amazon.com/Omnimount-10...00006I5KQ/ref=cm_cr_arp_d_product_top?ie=UTF8


Peerless Tablet Cradle for Tablets Less Than 0.75-Inch, Deep (PTM200),Black -> https://www.amazon.com/Peerless-Universal-Tablets-0-75-Inch-PTM200/dp/B0081XAWKG

And a 12" 1/2 x 1-1/4 Al bar extension.


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## JFL4066 (Apr 7, 2022)

Wow! Thank you for the info! I've been making mine.


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## Badabinski (Apr 7, 2022)

I'll be honest, I never expected to see Wireshark screenshots on this forum. Really appreciate the in-depth testing you did, and your endorsement is making me seriously consider trying to fit a DRO to my lathe.

I also like that the protocol is well documented. I don't really like using Android devices as appliances, but not having to reverse engineer anything means that it wouldn't be too much work (probably 3-6 months) for me to write a hacked-together frontend that I could run on a Linux SBC. It wouldn't have many of the really cool app features I've just read about that compelled me to edit this sentence in, but it'd be fun to write and I could do something dorky like hook up an amber phosphor serial terminal for that sweet 1980s vibe.

Gah! Why is this forum so good at making me drain my wallet‽


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## JFL4066 (Apr 8, 2022)

Badabinski said:


> Gah! Why is this forum so good at making me drain my wallet‽


LOL. Yes but in a really good way!

Yuriy designed a very nice well thought out product. And, I really like supporting his efforts.


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## sdavilla (Apr 8, 2022)

Real easy to talk to the TouchDRO controller. Only took me a few hours to get a basic fetch and dump from device, running under OSX. A few hours more to get bluetooth APIs talking directly to it. Piece of cake.


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