TouchDRO Build 2024-03-11 (Beta)

[ycroosh]

Louis,
Sorry for the delay - had to push a bug fix ASAP.
So, I'm a bit confused (I think) - I though you had the probe inverted to have the LED light up brightly. That would make your probe normally-open, no?

In any case, the hardware seems to be working (since you are getting correct behavior with NO probe).
The app should be working correctly since the last build. I tested the crap out of it over the last few days, and it handles probe input correctly.
The only thing that is left is firmware. I haven't had a chance to dig into it more, but will try tomorrow if nothing else catches fire.

Rev. 2.0 was the last revision of that adapter (Rev. 1.x had micro-USB connector on the front and the aux inputs were oriented differently. The circuit was identical. Rev. 1.0 written in pen ink is the firmware version. It was the only revision of the firmware.
The code checks the probe input during boot (it reads the pin status and sets it as the "default value" and sets the interrupt edge to be opposite from the default value). The code is brain-dead simple, so I don't understand how it's mis-behaving:



I'll keep digging.
Regards
Yuriy

OK, found it I misspoke about v1.0. V1.1 was the version that shipped on most adapters. V1.0 had different probe code and existed for a couple of months in 2021.
It looks like you are in Portland. You can ship the boards back and I will re-flash them with 1.1.

 

[Backporch]

Hi Yuriy, No worries, the many outweighing the one...or something like that

My probe interface starts at +9.1v (had it available as the regulated input voltage for the battery charging controller) through an E-103 10mA current regulating (limiting) diode, a several hundred ohm current sense resistor then through the probe to ground. A window comparator using a dual comparator with open-collector outputs "looks" across the sense resistor to differentiate probe current between three levels:

probe no-touch - contacts closed (current is 10ma limited by diode - above window): TouchDRO probe input = ground
probe touch - contacts open, LED active (LED current inside the "window"): TouchDRO probe input = open
probe disconnected (no current - below window): TouchDRO probe input = ground.

It's been a while but I vaguely remember the 10mA probe current came from discussion with Andrew as a good tradeoff between contact cleaning and contact wear.
I think the LED current ends up around 650uA. The "UPS" battery powers only the module and the scales and not the probe or tach so the 10mA/~91mW probe current/power isn't an issue for battery hold-up time.
-------------------------

Baffling indeed... I did another experiment and the spam isn't spam, it's just reacting on the wrong edge (or level) but maybe you already figured that.

In the snippet below the board is powered up with the input grounded (using a switch) then the serial terminal is connected and the p channel is quiet. When the input goes high nothing changes. When the input is taken low again it outputs p1s until the output is taken high then outputs a few p0s and goes quiet. Repeated it several times in the snippet below.

Looks very similar to the normally open case. Can't tell the difference between actions due to edges or levels but the the code snippet you posted above seems pretty straightforward.

12:44:29.867 Connecting to TouchDRO ...
12:44:32.212 Connected
12:44:32.234 x0;y0;z0;w0;p1;t0;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p0;p0;p0;p0;p0;p0;p0;p0;p0;p0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;t0;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p0;p0;p0;p0;p0;p0;p0;p0;p0;p0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;t0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p1;p0;p0;p0;x0;y0;z0;w0;p0;p0;p0;p0;p0;p0;p0;t0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;t0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;p0;p0;p0;p0;p0;p0;p0;p0;p0;p0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;t0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p1;p1;p1;p1;x0;y0;z0;w0;p1;p1;p0;p0;p0;p0;p0;p0;p0;p0;p0;p0;x0;y0;z0;w0;x0;y0;z0;w0;t0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;x0;y0;z0;w0;
12:45:36.064 Disconnected

A head scratcher indeed.

Cheers, Louis

 

[Backporch]

Our messages crossed in the ether. Glad you found it!