Display Jumping - Random Numbers Flash

[EmcoDude]

Hi,
This is a new install on My Emco Super 11 with mill.  I purchased Igaging DRO Absolute Plus scales and used the display that came with them at first, all work correctly.

I swapped the USB cables to a new Adapter for iGaging Scales and have been having issues with display jumps and random numbers flashing.  Also the display will jump .0004 than go back. This happens on all 3 scales.

I soldered a .1uf cap in the scales.  Now I see some folks use a 1uf cap, did I install the wrong size one?

I have tried a wire from ground on adapter board to lathe, no change  

Not sure what to try next, it seems from searching the forum the cap fixed these issues.  

Thanks for any help

Kevin

[Yuriy]

Kevin,
The .0004 jumping (flickering) is inherent to the scales and you can't fix it with caps or any other hardware changes. All iGaging scales do it, but their display masks the issue by averaging a lot of reading (at least on the older DigiMag and Absolute Scales; EZ-View now does that with the native display). You can make it less annoying by enabling "Digital Filter" in TouchDRO settings. It uses some statistical shenanigans to reduce the flicker without introducing the lag that the native displays.
Random number flashing (assuming it's not just 0.0004") is not normal for Absolute scales (at least it hasn't been in the past), since this is usually caused by noise in the clock line that confuses the EZ-View 21-bit scales. I wonder if iGaging changed the Absolute scales to use the same electronics as EZ-View. For the sake of experiment, can. you try something:
Plugin the scale into the TouchDRO adapter and move it to some random position
Note the position the tablet displays
Unplug the TouchDRO adapter from the power
Short out Pins 1 and 5 next to the Micro-USB plug for 30 seconds (to drain any residual capacitance in the scale and the board)
Being careful not to move the scale, power up TouchDRO, connect to the tablet, and check the position.
I'm curious to see if it changes or stays the same.

Thank you
Yuriy

[EmcoDude]

Thank you for the fast reply! and on New Years Day

The display did not change.

I enabled digital filter which did not seem to make much difference with the .0004 but it did seem to make the display lag a bunch.  Move the cross slide and the display takes longer that I think it should to catch up.

I am using a Fire 8" Tablet.  No issues getting your app on it.

I am new to DRO use.  This lathe my brother and I purchased new in 1986 and it is now at my house, so its been 33 years since I last used it.  long story...

Here is a video https://youtu.be/NAapC5KIHnY

Kevin

[NormanP]

Hi guys, I see similar random jumps on the 3 iGaging Digimag type scales I've fitted despite using shielded and grounded cables. Did the test completed above give you any indication how to resolve this issue? Will installing 1uF caps at the reader help?

[Yuriy]

NormanP,
Can you include more details about your setup?
Jumping by 0.0004" up/down you can't fix. That is inherent to the scale and the only workaround is to average a bunch of values to smooth it out (i.e. make the scales slower). Other types of random jumping can be caused by all sorts of things, ranging from loose connections, noise in the power lines, to individual scales being more sensitive. iGaging used a dozen or so different PCB revisions. Some of the older ones were more prone to random jumping than others. Newer iGaging EZ-View seems to be doing much better with noise.
Regards
Yuriy

[EmcoDude]

Yuriy,
I see on your Facebook page that you started shipping a new board and new firmware. In case others can't see the FB page:

"Finally, the board comes with the newest firmware (V2.4) that has a number of stability tweaks. Namely, it handles the latest EZ-View scales better. iGaging slowed them down by a factor of magnitude, from 50Hz refresh rate to less than 5Hz, so I tweaked the clock frequency a bit and added more error correction logic."

Have you had any feedback on this new firmware that it resolves the issues people are seeing? Or do we need the new board and new firmware?

Kevin

[NormanP]

Hi yuriy,

Thanks for getting back to me.
The setup I have is a diy build based on a recent msp430 launchpad. The scales are these:

https://www.arceurotrade.co.uk/Catalogue...te-Display

The issue I have is every few minutes, a reading jumps to what appears to be a random number and then immediately jumps back to the real reading. This happens to all 3 of the scales.
The problem happened even when the scales were not mounted to the mill (when I was testing the build). Now they are fitted, issue still occurs if there is power to the mill or not. DRO Power supply is a USB wall plug. USB cables have been replaced with foil shielded type and the foil is grounded to the power supply -ve line. 1uF caps are fitted across each of the scale power lines at the pcb end. 3v Battery back up is fitted to power the scales when the mains powers off.

Any and all suggestions to solve the random reading jumps appreciated. Thanks.

[Yuriy]

Norman,
Do you have means to re-program the MSP430 microcontroller? Your kit likely shipped with V2.1 firmware. I've made a few changes in the current V2.4 firmware, and I'm curious if they would make any diffrence.
iGaging EZ-Vew scales work around this by averaging 11 readings. The scales I have don't have large jumps, but one of them "dances" around the stable value quite a bit. The original display hides it, since it refreshes only about 4 times per second. I try to refresh 20 times per second, but for some setups this might be a bad tradeoff. I'm experimenting with a few different thigs, but so far haven't found a good solution that works across the board (some scales don't like to be read too fast, or they simply reset).
Thank you
Yuriy

[NormanP]

Hi Yuriy,

Yes I should be able to load a new firmware.

Cheers,
Norman

[NormanP]

Hi Yuriy,

Do you have any further thoughts or updates on this issue? 

Regards,
Norman