Calibration Bridgeetek BT81x example on Riverdi display


Hi guys,
I’m using the example for Brigetek BT81x chip on a Riverdi IoT resistive display.
It works initially fine up to an issue with callibration.
Since the display is a resistive one, the calibration part int eh example has to be uncommented:
# bt81x.dl_start()
# bt81x.calibrate()
# bt81x.swap_and_empty()
After the manual calibration on start the result seems to be everytime very imprecise and the tap on buttons is triggered with an obvious offset.

Did anyone have the same issue?
Any idea how to localize the reason for this issue?

Best regards


Hi @alexh225,

we tested the calibration procedure with resistive displays, too.
Can you try to replace from riverdi.displays.bt81x import ctp50 with from riverdi.displays.bt81x import rtp50?

Are you trying the DisplayWidgets example?


Hi Lorenzo,
yes, I’m using the standard DisplayWidgets example to avoid side effects…

It’s a good hint from you regarding the rtp50 module. But I still see most of the time an offset to the left side ~20px. And I’m testing a pen - so it’s not my “fat finger” :slight_smile:

But if you say, that you cannot reproduce the same behavior on your site, it could be an issue with the Riverdi display, maybe. I will get a second device soon, so I can compare it then.

By the way, there is also a bug in the DisplayWidgets example that cause an "IndexError" and forces the program / panel to be restarted.

To reproduce it, just tap on any other UI component (title text or the dynamically added spinner, clock).

The point here is that in this case the widget_choice_cbk method gets with "_widget_choice" parameter a value of "255" and an invalid index will be calculated for the widgets array with a length of 5.

So far, my basic interpretation from reading the documentation.



Hello @alexh225,

thank you for reporting the issue, we will try to fix it ASAP.
Have you had the opportunity to test on another Riverdi display?

Let me know :slight_smile:


Hello Lorenzo,
I’ve got additional evaluation Displays from Riverdi today and it Looks fine this time.
The vm was discovered and downloaded by the Zerynth Studio as expected this time.