Does It Exists, 3 Axis Display 4 Igaging Dro?

lens42 said:
Your Mitutoyo box appears to have Data and clock inputs rather than A and B inputs, which leads me to think it wants to see something like I2C serial data
Click to expand...
I2C has only data and clock lines (both bidirectional). This also has a "request" line. Looks like a proprietary interface to me. You'd have to reverse-engineer it. I could do that, but not from here. I'd have to have the hardware on my bench.
 
John Hasler said:
Very different. RS422 is a differential digital electrical signaling standard. TTL in this context refers to the voltage and current levels required to interface TTL integrated circuits to each other on a circuit board and really shouldn't be used for data transmission.

RS422: https://en.wikipedia.org/wiki/RS-422

TTL: https://en.wikipedia.org/wiki/Transistor–transistor_logic#Interfacing_considerations

While they can interoperate to a limited degree you lose all the advantages of RS422 and gain all the disadvantages of TTL.

You may be thinking of RS423. It will interoperate somewhat better with TTL being an unbalanced system.

https://en.wikipedia.org/wiki/RS-423
Click to expand...


What I was getting at was that the Ditron scale is pinned to do either TTL or RS422. If you just read the TTL pins via your DRO you will get numbers to appear on your DRO that are accurate. If your DRO can interface completely with RS422 you will get numbers that are more accurate on your DRO. But for most of us in the hobby field reading the scale just using TTL (high/low voltage) works just fine. This was a question I got hung up on for a while while building my DRO. In the end the Touch DRO using quad scales (glass or magnetic) will just be interfacing using the TTL format, even if your scale has the additional features capable of using RS422, Touch DRO is setup as a simple logical interface.
 
John Hasler said:
How badly busted up is the X-axis scale? I might be interested in it (the box and Y-axis too, but I probably can't afford that).
Click to expand...

Hi John, see the thread I started back in Sept. -=- Link -=- There's picts, it's all busted up.
The X-Axis they put on the table looks to have been a 700mm long one. Too short for the 48" table on the mill.
I'd say that they probably crashed it within the first week.
 
Ha ha no worries. I have no idea what half the last posts were talking about, but my googlefu is strong!
 
middle.road said:
Hi John, see the thread I started back in Sept. -=- Link -=- There's picts, it's all busted up.
The X-Axis they put on the table looks to have been a 700mm long one. Too short for the 48" table on the mill.
I'd say that they probably crashed it within the first week.
Click to expand...
That looks totalled, alright. Too bad.
 
Okay, here's the latest on using igaging Absolute scale with Touch DRO.

From Yuriy's Toys:
Yuriy/Frank
Thanks for the reply.
The tablet having connection issues is a Verizon Ellipsis 7. Android 4.4.2 Build 3.4.67 Model QMV7A.
Bluetooth is running at 9600 baud.
I got hold of a Samsung Galaxy Tab 4 to test. It works fine with touchDRO and reads the Arduino Bluetooth OK. So the issue is with the Bluetooth on the Verizon Ellipsis. Using the Samsung is the easiest solution to the problem for me.
Another question:
Does anyone have info on the data format for the iGaging AbsoluteDRO scales?
I figured out it is very similar to the Mitutoyo SPC. There is a data line and clock line.
Sending a block of 52 bits about 10 times a second.
I can read the data OK with the Arduino. But I can not make any sense of the 24 data bits.
It does not seem to be BCD like the Mitutoyo.
Interesting puzzle to unscramble the bits.
Thanks
Coleman

Yuriy KrushelnytskiyAugust 3, 2015 at 10:51 AM
Coleman,
I've plaid some with the Absolute scales, but so far I can't figure out the protocol and the iGaging guy I talked to didn't know the protocol either. I haven't made this into my top priority though, as there is too much work with the app right now and I don't want to get too distracted.
Thank you
Yuriy
********************************************************************
Had a freind at work connect one of my scales up to him O-scope. Here's what he had to say:
Ok, did a little research. Turns out it's a 52 bit Mitutoyo protocol, and Instructables has an article on interfacing an Arduino to calipers using this format.
http://www.instructables.com/id/Interfacing-a-Digital-Micrometer-to-a-Microcontrol/

13 digits, 4 bits per digit. Odd format.
Oh, it also appears that the magnetic strip encodes the position. That means the DRO can be made absolute, also!

Here's a cople snapshots he sent me.JimmyTrace.jpeg JimmyTrace1a.jpeg JimmyTrace1b.jpeg
 
Okay, here's the fix for using iGaging Absolute scales with the Touch DRO App.

First, no hardware changes needed.

Second, Have to change 3 numbers in the sketch (at least for the Arduino)

  1. Change clock speed to 2KHz clock

  2. Delay to 70 msecs

  3. Data stream from 21 bit to 52 bit.
Lastly, it appears the magnetic strip is encoded. Thus, even with a power loss, the scales won’t lose position. No need for the battery back-up.
 
You must log in or register to reply here.
Back
Top