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Showing posts with label kiosk. Show all posts
Showing posts with label kiosk. Show all posts

Saturday, June 20, 2020

Building a hardware watchdog timer for a kiosk or other system that needs to run 24x7 - version 2.0


My previous post covered a first version of a watchdog timer that I used in the past for another project. 

You may check it here.

As I mentioned there, I suspected that a somewhat different design would be necessary, because the target device could not have either GPIO pins available for allowing a keep-alive signal to be sent to the watchdog timer, or even if it had, it would be unlikely that the underlying linux OS on the Android system could not have the necessary drivers or support for changing the output of such pins.

Saturday, May 2, 2020

Building a hardware watchdog timer for a kiosk or other system that needs to run 24x7


It was proven by Alan Turing back in 1936 that the halting problem applies for computing in general, and our contemporary computing machines are no exception.

Would predicting the crashing of an algorithm or program be a possible function, and we would be able to know the edge cases that cause an application to fail or enter a loop, without having to explore the actual scenarios to find these edge cases. To put it simply we would only have to ask the algorithm in which conditions it would enter a loop or end unexpectedly, and by not providing these inputs we would with absolute certainty not enter these scenarios.

Monday, April 27, 2020

Building a kiosk for Home Assistant from scrap parts - Part 2


With a project of this type, the hardware preparation is just the tip of the iceberg. It was thoroughly explained in the last post, despite one last change still being pending. What lacks is basically the addition of a resistive touch panel to the front of the screen, in order not to depend on the mouse as a pointer/input device. The panel is still somewhere between China and my location..

The first aspect that I found important to cover, now that I had this Android based kiosk up and running, was the ability to remote control it and launch arbitrary applications and services on startup.