[Metrology] Touchdro - Controller - Glass Scales

middle.road

middle.road

Granite Stoopid...
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I'm starting this thread hoping to generate a detailed blow-by-blow account of setting up TouchDRO with Ditron Glass Scales.
After the scales are up and running I plan on adding a tachometer to the setup, but for now going to keep it simple.

I'm not exactly sure of which controller to use, or how to put it all together.
I realize that it's one of the TI MSP430's shown on Yuriy's TouchPro page, but even if was forced to chose I wouldn't be able to tell you with certainty which one.
(I'm hoping Yuriy will jump in here and point out the obvious to me... :grin: )

I'm going to be using a 10" HP TouchPAD tablet that is rooted and flashed to Android v4.4.4 with a Kernel version of 3.0.101.
The HP is a pretty tough tablet and they can be had 'used' on Ebay for under $60.
The only caveat is that they might have to be flashed for Android.

I want to set it up so that I have the option of doing both USB or Bluetooth. Reason for this is I'm not
100% certain that BT will work properly when all is said and done.

I also have not been able to figure out how to connect the 9-pin connectors on the Ditrons to the LaunchPad.
I've been reading so many posts that I've hit overload and am not certain which way to proceed, and need some help. (as usual.)
 
middle.road said:
I'm starting this thread hoping to generate a detailed blow-by-blow account of setting up TouchDRO with Ditron Glass Scales.
After the scales are up and running I plan on adding a tachometer to the setup, but for now going to keep it simple.

I'm not exactly sure of which controller to use, or how to put it all together.
I realize that it's one of the TI MSP430's shown on Yuriy's TouchPro page, but even if was forced to chose I wouldn't be able to tell you with certainty which one.
(I'm hoping Yuriy will jump in here and point out the obvious to me... :grin: )

I'm going to be using a 10" HP TouchPAD tablet that is rooted and flashed to Android v4.4.4 with a Kernel version of 3.0.101.
The HP is a pretty tough tablet and they can be had 'used' on Ebay for under $60.
The only caveat is that they might have to be flashed for Android.

I want to set it up so that I have the option of doing both USB or Bluetooth. Reason for this is I'm not
100% certain that BT will work properly when all is said and done.

I also have not been able to figure out how to connect the 9-pin connectors on the Ditrons to the LaunchPad.
I've been reading so many posts that I've hit overload and am not certain which way to proceed, and need some help. (as usual.)
Click to expand...

Dan,
First of all, I would avoid USB at all costs. BlueTooth is a LOT more reliable. I get almost no complains about BT (except when the person doesn't connect Rx->Tx) and all sorts of issues with USB, including more noise due to the extra ground loop.
Since you mentioned "Dirton", I'm assuming you are talking about glass or magnetic scales (i.e. quadrature output). If that is the case you need to use the Quadrature controller.
Since the scales run at 5V, which is fatal to MSP430 you will need to add a voltage divider or buffer on each input line. (two resistors on 74HC244 IC). The whole thing will set you back around $30-ish.
If you don't want to mess with building one and can wait till the end of January I will have the first batch of pre-made controller boards. I don't know the price yet (still waiting for a few quotes for assembly), but it will be somewhere between $75-$100. That option is obviously more expensive but you get nicer board, better interface (the board takes advantage of the complimentary signals as well (A' and B'), which might or might not matter to you), and don't need to fiddle with flushing, testing etc.
Hope this helps.
Regards
Yuriy
 
Watching as I'm dragging my feet on the same project. My biggest hold back is the work around on not being able to add all 5 scales I'd like to.
 
kingmt01 said:
Watching as I'm dragging my feet on the same project. My biggest hold back is the work around on not being able to add all 5 scales I'd like to.
Click to expand...
MtKing,
I will definitely not be adding that to the app. You are the only person so far that needs 5 scales and wiring the fifth axis throughout the app is a LOT of work. If you know exactly what scales you will be getting, how they will be installed etc I can give you custom firmware that combines the values in the controller. There is a version of MSP430G2553 chip that has enough input pins to handle the extra scales.
Regards
Yuriy
 
kingmt01 said:
Watching as I'm dragging my feet on the same project. My biggest hold back is the work around on not being able to add all 5 scales I'd like to.
Click to expand...
What machine do you have again? I can't remember. I searched but came up empty.
 
ycroosh said:
MtKing,
I will definitely not be adding that to the app. You are the only person so far that needs 5 scales and wiring the fifth axis throughout the app is a LOT of work. If you know exactly what scales you will be getting, how they will be installed etc I can give you custom firmware that combines the values in the controller. There is a version of MSP430G2553 chip that has enough input pins to handle the extra scales.
Regards
Yuriy
Click to expand...
I'd be grateful. I'm actually only wanting to have 4 axis readings. Two scales both move along the y axis & I'd like them totaled. Actually another two both move along the z axis but I really like being able to keep my knee reading separate from the spindle on my small mill so I assume I'll do this on the new larger mill also.

I'm still discussing my options with the quadrature encoders from the manufacture.
 
Hi Yuri, i have all the components that are on your site to build a quadrature Dro, just havent had time to build. I also have the Ditron glass scales. In your post you mention using 74HC244 IC? I havent got these as I didnt think Id need anything other than the voltage divider circuit for the 5v signals in? Should i build the voltage shifter circuit with the "comparitors"?........ I think that is what they are .

Thanks Ben
 
Str8jacket said:
Hi Yuri, i have all the components that are on your site to build a quadrature Dro, just havent had time to build. I also have the Ditron glass scales. In your post you mention using 74HC244 IC? I havent got these as I didnt think Id need anything other than the voltage divider circuit for the 5v signals in? Should i build the voltage shifter circuit with the "comparitors"?........ I think that is what they are .

Thanks Ben
Click to expand...
How does the quality of the Ditrons look? Any good?
 
This is from Ditron & just for reference. I copied it from an email I received.

here i quote for your reference .
linear scale DC11 125mm 5um 69USD/piece
linear scale DC11 175mm 5um 69USD/piece
linear scale DC10 400mm 5um 63USD/piece
linear scale DC10 400mm 5um 63USD/piece
linear scale DC10 550mm 5um 67USD/piece
linear scale DC10 800mm 5um 67USD/piece
linear scale DC10 1100mm 5um 76USD/piece

This doesn't consider shipping or banking fees. I also don't know the difference between DC10 & DC11.
 
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