Touch Dro Fix For Igaging Absolute Dro Scales (i Hope)

[JPigg55]

Well, my buddy Brian thinks he has this licked.
I'll be taking my controller and one of my scales to him friday so he can test it all out this weekend.
So, hopefully, will have the complete sketch & instuctions first of next week.
He's also working on a fix for the Launchpad version which I'll also post for those who have/prefer that vversion.

 

[Navy Chief]

Thanks for the effort on this, looking forward to the results of the testing. I am sure that the rest of the TouchDRO community will appreciate the input also.

 

[dlhoulton]

Would also like to thank you for your work on this. I have the Absolute DRO setup on my lathe and would like to have the ability to have a large wired display added for better visibility. I bet once this is solved there will be a large population of "Absolute" users very excited. Thanks again for the work your doing!!

 

[middle.road]

Question JP: does it interface with a device via bluetooth only or can it do hard wire and wireless also?
(I suppose I had better start reading up on this...)

 

[JPigg55]

It can be wired and/or wireless. However, it is designed to work with the Touch DRO App which is usually associated with Tablets and smart phones (not sure about Window 8 or 10. I've heard those computer operating systems interface/run App's, but not sure).
The App only works on Android devices currently (sorry iPhone & iPab users).
I personally would advise on going the wireless route. Less wire means less chance of EMI from shop motors and lighting. I think it will be more flexible as well, especially for use on multiple machines.
I did find out today there's an issue with the schematic on Yuriy's Touch DRO site (http://www.yuriystoys.com/p/android-dro.html) for the wireless Arduino version.
Arduino sends out a 5V signal on its TX pin, and the HC-06 Bluetooth module can’t have more than 3.3 – 3.6 Volts coming into it on the RX pin, so you need to put a voltage divider on that line to step the data signal voltage down. This isn't shown on the schematic or discussed on the site beyond telling you to refer to your specific Bluetooth module specs.
The schematic also shows the 5V supply going to the Bluetooth module. While it may work, it's better to supply it from the 3.3V pin or it may fry your module.
Right now, the issue seems to be the way the Bluetooth module is sending data to the App that's currently not working for me. May be the voltage issue.
I'll try re-wiring my controller tonight and test again. If not, my buddy Brian is sure he can fix the isse once I get my controller and a scale to him to play with.
Once it's tested SAT, I'll post the sketch and try to post an fixed schematic for the build.

 

[middle.road]

Pheeeew. I'm running HP Touchpads here. I received one as a gift after the fire sale back in '12 and I've become rather
enamored with them and they are the only tablet I like to dink around with, and I've had quite a number of others
pass through my hands the last few years. I think I've got six or so floating around here currently.
The developers are still pumping out Android on these and they're up to date with Lollipop.
One slight drawback is that the BT is not functional or at best 'flaky'.
Since one of these I what I'm planning on using, I was a bit worried there for a minute.

Thank you for the very informative reply, 'tis appreciated.

 

[JPigg55]

From Touch DRO site for minimum requirements:

System Requirements

• Android OS 4.0 or newer
• 4" multi-touch screen with 800x480 resolution*
• BlueTooth or USB support

* Altough the application will work on a 4", or even smaller, screen, a tablet with at least 7” 1024x600 screen is highly recommended.

 

[middle.road]

Got that covered. The Touchpads are 10" and resolution is 1024x768. Should make for a decent interface.
I've got several flavors of KitKat (v4.4.4) and Lollipop (v5.1.1) running on them.
I've seen picts of it running on a ~4" smartphone, but I don't believe that I would care for that. - Fat Thumb Syndrome -

 

[dlhoulton]

Is this at a phase where one could start ordering parts for the build? If so, is this just for the "Arduino Basic DRO Controller? Going the Bluetooth route is not a problem and from what info is on Yuriy's site this is the simplest to build.

 

[JPigg55]

I wouldn't order just yet.
Right now not sure if issue lies with controller trying to send a 52 bit number to the App or the App itself.
If it's the controller, should be able to fix it in the next few days, but may require using a different Arduino board. Might take using the Arduino Due instead of the Uno.
If it's the App, we might be at an impass unless we can get Yuriy to modify the App to accept a 52 bit number. Not sure if he'd be willing or able to or if it's even possible. I'm not up on the whole App building thing by a long shot.
For those like me who have already built controllers, I'm attaching a modified version of the schematic showing the req'd changes. You'll have to excuse the art work. I'm no artist and don't have a good drawing program (used Microsoft Paint).
The changes are:
- 3v power to Bluetooth module instead of 5v.
- Voltage divider pn TX to RX (Arduino to BT). I used 10 ohm and 20 ohm resistors to drop the 5v signal from the Arduino to 3.3v. Any resistors should work as long as one as one is about double the other. Voltage needs to be 3.3v to 3.6v.
- I didn't change the schematic, but the capacitors on the power leads (Vcc) to the scales aren't necessary. Provides some filtering and can be used, but not necessary.