T-DRO won’t let tablet sleep.

[ChazzC]

Because form Android's perspective "in use" means that you are touching the screen. The OS doesn't care if the screen is changing or not.
With TouchDRO (if you're using it as intended), you should be hands-free most of the time. I.e. set up the workspace/layout, turn on auto sub-datum selection, and go.

To be clear, the flag to keep screen on works ONLY when TouchDRO is in the foreground. It is per app. You'll notice that some other apps do this too. Many higher-end tablets have a feature that uses the camera to recognize your face, and as long as the camera registers you staring at the screen, the tablet won't go to sleep.

As I mentioned, one could set screen timeout to something very long, but that means that you would know that this is a thing, and how to do it. Many don't, and screen turning off in the middle of an operation can be a major inconvenience. TouchDRO will preserve the position and any of it's state, but if the screen goes blank when I'm single-point tapping a 10 TPI thread into a blind hole, blank screen would at least mean a scraped part.

But going back to my earlier comment, when you are done, tap the power button. I don't leave my tablet running when not in use, and don't find a button click to be too burdensome.

Regarding carried position - how does that work with other DROs? With glass/magnetic scales, the scale would need to be powered up. I understand how one could save last known position, but unless a DRO has a backup power source, any movement will desynchronize the scales. I haven't seen this on any of the import DRO's I've touched. Do the "big guy" DRO's come with a built in battery?

Regards
Yuriy

So the TouchDRO iGaging adapter also has (an optional) feature: it supports a LiON battery that maintains the iGaging head’s position memory [I think I described it right].

 

[ycroosh]

Capacitive scales use micro-Amps worth of current, so a very small LiPo batter can keep them fully powered for months. Even with the TouchDRO adapter fully powered off, the position is retained in the scales.
Glass, and especially magnetic scales need 5V and 100-ish milli Amps, and the position is stored in the TouchDRO adapter memory (the scales are simple quadrature encoders). Even if the scales were powered, the moment the DRO looses power, position is gone. If the DRO is powered but the scales are not, moving the spindle will de-synchronize the scale positions.
I just spent a few hours reading sales brochures for high-end DROs, and none mention any sort of uninterrupted power supply capability. I suspect this is not a thing.

The new generation of TouchDRO hardware has a way to recover position IF the scales were not moved. When the power to the adapter is cut, a super capacitor can power the chip for about 50 milliseconds. During that time the code flushes out the last position to on-board EEPROM. The complicated part is actually NOT doing this if the scale was moving at the moment the power was cut. I had to do all sorts of gymnastics with timer and check sum calculations to ensure that the data is written correctly and only if the DRO wasn't in use.

 

[ChazzC]

Does your tablet have wireless charging? If so, or if you replaced it with one that did, you could have wireless charging pads hard mounted and cabled at each machine and then you'd get power just by setting it on the stand.

Or do what I did: when I’m using the lathe, the tablet runs on its battery; when I’m done, I move the tablet to its charging location in the shop: after 4 hours of use, the tablet’s (Fire HD 8, 13 hr battery life) has never dropped below 70%. However, this tablet is dedicated to the lathe TouchDRO readout, so isn’t expending much effort.

 

[RJSakowski]

I keep my 1st generation Touch DRO adapter and the tablet on a.c. power 100% of the time. I don't power down the tablet when it's not in use. In spite of having been in service for more than four years, I haven't seen any evidence of screen fatigue.

 

[RaisedByWolves]

Capacitive scales use micro-Amps worth of current, so a very small LiPo batter can keep them fully powered for months. Even with the TouchDRO adapter fully powered off, the position is retained in the scales.
Glass, and especially magnetic scales need 5V and 100-ish milli Amps, and the position is stored in the TouchDRO adapter memory (the scales are simple quadrature encoders). Even if the scales were powered, the moment the DRO looses power, position is gone. If the DRO is powered but the scales are not, moving the spindle will de-synchronize the scale positions.
I just spent a few hours reading sales brochures for high-end DROs, and none mention any sort of uninterrupted power supply capability. I suspect this is not a thing.

The new generation of TouchDRO hardware has a way to recover position IF the scales were not moved. When the power to the adapter is cut, a super capacitor can power the chip for about 50 milliseconds. During that time the code flushes out the last position to on-board EEPROM. The complicated part is actually NOT doing this if the scale was moving at the moment the power was cut. I had to do all sorts of gymnastics with timer and check sum calculations to ensure that the data is written correctly and only if the DRO wasn't in use.

If nothing else I’m certainly learning a lot.

Sorry for the confusion over the units in our shop and how they act. I mentioned we have shop wide ups as losing power to certain machines wipes the program so to speak and it’s a biotch to get them running again.

I had figured that as long as the adapter was powered the scales would stay “active” as ours do normally outside of our ups system.

When I started pulling power plugs out of them vs shutting them down is when things got interesting.