Concurrency Issue?

[PJ789]

Noticed while using Snap 4 Arduino 1.2.7... if I interact with a single Uno from event driven code blocks in two or more sprites... it gets very confused and often becomes unusable/unresponsive.

I guess S4A missing some kind of mutex to serialize concurrent access to the Arduino Firmata code from multiple sprites.

[PJ789]

To add… OS is Windows 10. s4A is 1.2.7. Arduino IDE is 1.8.9. Arduino is an Uno clone with an FT232 connected to COM14.

[PJ789]

Here's a slightly better example.

I have two simple code blocks each of which control 1 of two LEDs (as prev).

If I connect the Arduino manually, and run the code, one of the two blocks will cause a confusing error message to appear "Inside: Error Arduino not connected".

issue_289_example2.zip

[PJ789]

Am I right in thinking... one Arduino can only be connected to/controlled by one sprite? Therefore, any custom code block that operates in the context of a second sprite that is not connected to the Arduino won't work? Obviously, that restriction could make it a little difficult to create tidy code that controls multiple devices via a single Arduino interface (.... without also modelling the Arduino itself as a controller sprite perhaps).

[bromagosa]

Exactly. An Arduino board is a property of a single sprite.

If you want a sprite to interact with the Arduino board that another sprite has connected, you need to use "tell sprite to do", from the Control category, or broadcast messages.

[PJ789]

Thank you.

I love what you've done with Snap4Arduino. Good luck with your launch in September.

I'm running a childrens workshop at the beginning of October… and plan to use Snap4Arduino (with Nanos).