CurieBLE: StandardFirmata BLE does not work.

[sandeepmistry]

I'm testing the latest master release with PR firmata/arduino#335.

However, I think the board is crashing - I don't see the 101 advertising using BLE, and the next time I try to load a sketch I have to press the master reset button.

I would expect the sketch to work with @soundanalogous's Node.js test app: https://gist.github.com/soundanalogous/927360b797574ed50e27

[sgbihu]

Hi @sandeepmistry ,

I has shoot the root cause of this issue. The Firmata try to add profile before HW initialized. That makes the program crashed. So I move some process from BLEStream constructor to begin and that makes the program works. I can discover the profile with another 101 board.

The fix commit ID is 10c482f. My github is https://github.com/sgbihu/corelibs-arduino101.

I didn't test with https://gist.github.com/soundanalogous/927360b797574ed50e27. Because I don't have access to it. And I didn't know how to set the environment. So can you help test it?

[SidLeung]

This issue is logged as Jira #791.

[SidLeung]

This issue is logged as Jira 791. Solution from Liang under internal review, testing. Will update status here upon completion.

[sandeepmistry]

Hi @sgbihu,

There are a few concerns about the items you proposed in #377 (comment):

1. It requires a change to the upstream Firmata library. I would prefer we explorer a change to the CurieBLE library itself as other user sketches might follow the same pattern.

2. If a BLEStream::begin(...), BLEStream::end(), BLEStream::begin(...) sequence is followed the attributes will be added again in begin.

[SidLeung]

Hi, @sandeepmistry

Agree with you that this is not the solution.

The issue actually exposes a problem with the robustness of the BLE library initialization process and we are going to address it (instead of making changes to the 3rd party code).

The cause of the system crash can be traced back to the instantiation of a global object using a constructor that makes BLE API calls at the time when the BLE library has not been initialized.

The instantiation of global object is (determined at compile time) done as part of the system power cylce/reset initialization. Object instantiation is performed by the Class Constructor. The BLE objects, however, are instantiated at run time (in order to reduce heap space and BSS consumption for sketches that do not use BLE), via the, begin(), API call in a sketch. Thus, if BLE API's are called in a constructor of a global object, these calls are made prior to proper BLE initialization.

We are working a solution to overcome this issue.