Using HF calipers

[chucketn]

I ordered and received new 9" tablet running Android 4.4.4. Seems my Bluetooth connection problems are improved, but are still troublesome.
I stumbled upon the cpi setting for the HF scales on one of the blog posts (2000) and now have one axis connected and calibrated. Readings agree with scale within .0005".
My newest issue is when the TouchDRO is entered into any settings area, the BT connection shows disconnected, but I still get readings from scale.
If anyone is interested, I built a logic shifter for the scales clock and data with 2N2222A transistors and 10 K ohm resistors. I only had 2ea 2N2222As so only one scale connected(more on order).

I want to add my thanks to Yuriy for sharing his work on TouchDRO.

Chuck

[leepeedin]

Just an FYI - with the latest software release, I too, get the disconnect message everytime I go into settings. An, in fact, it does disconnect from the BT device. I'm using Al Bassitt's bluDRO controller.

[chucketn]

Just an FYI - with the latest software release, I too, get the disconnect message everytime I go into settings. An, in fact, it does disconnect from the BT device. I'm using Al Bassitt's bluDRO controller.

My current setup:

Android 4.4.4
Harbor Freight 'Pittsburg' 4" caliper
Arduino Uno, running  Martin's caliper sketch from : https://sites.google.com/site/marthalpro...al-caliper
Caliper clock and data lines logic shifted
Caliper powered from Arduino 3.3v using resistor voltage divider(works also if caliper is powered by its original battery)
Android running TouchDRO v2.5.10

TouchDRO works if caliper is first set to inch display. TouchDRO will display correct inch reading in inch mode and correct mm reading in mm mode. X axis CPI set to 2000. I found the cpi value online somewhere, can't remember where or I would credit it here.

Only problem I have to figure out is : If caliper is powered off( by removing wall wart connection to Arduino, or removing battery), when caliper power is restored, the caliper display returns to MM. The TouchDRO displays incorrect information until caliper display is set back to inch display. This would be a problem when setting up to use if the caliper display button is not easily accessible.
I have not found a way to change the caliper display from mm to inch other than the blue mm/in button. I can solder, but adding a remote switch to the caliper circuit board would be extremely difficult.

I think the key to this problem is finding the pulses per mm output of the caliper in mm display mode, but I do not have an o'scope... I did find that setting the cpi of the x axis on TouchDRO to 100, the mm display of the TouchDRO is the value of the caliper in inch display mode...

Any suggestions?

Chuck

[Yuriy]

Just an FYI - with the latest software release, I too, get the disconnect message everytime I go into settings. An, in fact, it does disconnect from the BT device. I'm using Al Bassitt's bluDRO controller.

This is by design. If there is no "listener" for certain number of seconds, the background service disconnects from BT socket. I did that so the app doesn't use CPU resources while not displaying a position. When you go back to the main DRO screen or the Layout View screen the app should reconnect almost immediately.

---

Just an FYI - with the latest software release, I too, get the disconnect message everytime I go into settings. An, in fact, it does disconnect from the BT device. I'm using Al Bassitt's bluDRO controller.

My current setup:

Android 4.4.4
Harbor Freight 'Pittsburg' 4" caliper
Arduino Uno, running  Martin's caliper sketch from : https://sites.google.com/site/marthalpro...al-caliper
Caliper clock and data lines logic shifted
Caliper powered from Arduino 3.3v using resistor voltage divider(works also if caliper is powered by its original battery)
Android running TouchDRO v2.5.10

TouchDRO works if caliper is first set to inch display. TouchDRO will display correct inch reading in inch mode and correct mm reading in mm mode. X axis CPI set to 2000. I found the cpi value online somewhere, can't remember where or I would credit it here.

Only problem I have to figure out is : If caliper is powered off( by removing wall wart connection to Arduino, or removing battery), when caliper power is restored, the caliper display returns to MM. The TouchDRO displays incorrect information until caliper display is set back to inch display. This would be a problem when setting up to use if the caliper display button is not easily accessible.
I have not found a way to change the caliper display from mm to inch other than the blue mm/in button. I can solder, but adding a remote switch to the caliper circuit board would be extremely difficult.

I think the key to this problem is finding the pulses per mm output of the caliper in mm display mode, but I do not have an o'scope... I did find that setting the cpi of the x axis on TouchDRO to 100, the mm display of the TouchDRO is the value of the caliper in inch display mode...

Any suggestions?

Chuck

In theory the calipers should tell the controller what mode they are in (one of the bits is set to high for inches). It looks like this is not happening. You could leave the calipers in metric mode and re-calibrate the DRO to that CPI (and you should calibrate the DRO either way; don't use the "default" settings.

Regards
Yuriy

[chucketn]

I have tried calibrating cpi to the mm output from the module. When I do that, the inch setting on the DRO is correct but changing the DRO to mm is not.

Chuck

[chucketn]

Explain this please. TouchDRO refuses to connect and stay connected to the BT module on the Arduino. But, the x axis shows the caliper reading, and the BT module led shows connection...DRO axis displays are greyed out.
What is the correct data format out of the Arduino/BT?

Chuck

[chucketn]

Now, trying to modify my working(somewhat) sketch to add calipers for Y and Z axes. original sketch declared pins for clock and data as
int clockpin = 2;   and int datapin = 3;

I changed them to
int Xclockpin = 2;   //x axis clock
int Yclockpin = 4;   //y axis clock
int Zclockpin = 6;   //z axis clock

I get an error when compiling 'expected initializer before 'int' ' with the int Xclockpin  line highlited. Can anyone explain what I'm doing wrong? Is it the fact that I've capitalized the X? not the capital, Not the caps, tried without

Chuck