Thread: Hammeer K3 DRO project (Main and Crosscut fences)

Originally Posted by Bernmc

New version of the mounts printed and installed. Added a screw to lock the encoder strip, and enlarged the insert that sits in the extrusion, so it's more stable/solid.

Attachment 504652 Attachment 504653

I couldn’t stand having that colour on a machine, no matter how good the fitting looks or works, the colour of it is wrong. Unless…….

Originally Posted by riverbuilder

I couldn’t stand having that colour on a machine, no matter how good the fitting looks or works, the colour of it is wrong. Unless…….

There's a purple Mars lathe on FB marketplace at the moment... right up your alley, Peter

I had some time to fiddle with electronics today, and cobbled up Yuriy's circuit to get the iGaging scales to talk to my old nexus7 android tablet.

It's pretty simple - brains by an arduino (I had an UNO lying around), a bluetooth module to talk to the tablet, and a few resistors and wiring to some micro USB connectors for the scales.

It all works as advertised, and talks happily to the standard iGaging encoder strip. The question now is whether I can get it to work with the smaller all-in-one iGaging readers - like the Precision Pro on the crossfence, and the cheapo electronic protractors, to get an angle gauge. These don't have the USB connector to output to the touchDRO interface that the standard encoder does.

I need an oscilloscope to do that. Maybe father christmas will swing by early.

touchDRO test.jpg touchDRO board.jpg touchDRO screen.jpg

Pulled the DRO's apart to do some more tinkering

The 'Pro' is a combined display and reader.

Front: pro front.jpg

Back: pro back.jpg

The white strip sits on the encoder. The lead is a female USB plug so you can power that way instead of using a battery.

I opened up both the Pro and the EZ DRO:

pro v EZ open.jpg

The EZ (top) has a traditional mini USB connector. (One of the recommendations to improve reliability is to remove this and hardwire directly to the board.). On the Pro, the USB lead is hardwired, and only ground and VCC are connected.

Closer Clarice...

pro open.jpg

The connector strips aren't in the usual USB configuration - I think they're the cheapo connector that some of the low end Chinese instruments use. From a bit of internet diggings, it seems that this reader does come in a separate reader/display configuration. The display looks similar to the stackable displays that iGaging uses, and it also has the cheapo connector - the labels correspond to the pin markings on my board.

ZDA250-H display unit.jpg

I thought I'd try wiring up a USB male plug with the clock and data lines to the corresponding cheapo pads, and see what happened.

pro connector closeup.jpg ===> pro usb connected.jpg

Still alive, thank goodness:

pro still works.jpg

but sadly, it doesn't speak the language of my people. No response when connected to the TouchDRO arduino and android app, so there's either nothing coming out of those pins, or it's not in the same configuration as the EZ-view DRO reader. I can't investigate this any further until I have an oscilloscope, which should arrive in a week or so.

While I had the EZ-view open, I took the opportunity to add a bypass capacitor between ground and VCC - another simple mod recommended to improve reliability and protect the scales from voltage spikes.

EZ inside closeup.jpg ===> EZ bypass cap.jpg

I'm going to send a message to the manufacturer of these scales to see if they'll give me any more info, and to see if there's a simple way to reverse the =/- reading direction. Whether they'll talk to me remains to be seen.