New (soon to be) TouchDRO user.

[sdavilla]

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.

 

[buffdan]

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

 

[ycroosh]

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

 

[sdavilla]

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.

 

[ycroosh]

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

 

[sdavilla]

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.

 

[sdavilla]

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

 

[ycroosh]

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

 

[sdavilla]

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.

 

[sdavilla]

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 ?