noble/bleno

Only first indication received when running on Linux

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#242 opened on Nov 1, 2016

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help wanted

Description

I have a Characteristic with an indicate property. When a central subscribes to it and I start sending data using the updateValueCallback property, I only get one indication back. Subsequent indications are not received. This only happens on Linux, Raspbian in my case, not on macOS (10.11.6).

Example Project: https://github.com/mattsson/bleno-onindicate-bug.git

There's also a small Xcode Project in there which will build an iOS app that connects to the peripheral and logs out received data.

Debug logs: https://gist.github.com/mattsson/e15f62789661bf7b6e1941be1308d4ba hcidump: https://gist.github.com/mattsson/2da888db72b502fdc36f2b2897777d13

Contributor guide

Tech stack
javascriptnodejs
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Basic understanding of BLENode.jsLinux debugging tools (hcidump)
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Investigate the difference in BLE indication handling between Linux and macOS. The hcidump logs and debug output provided in the issue show that only the first indication is sent. Look into bleno's implementation of the updateValueCallback and how it interacts with BlueZ on Linux. Check if there is a missing completion event or a need to wait for confirmation before sending the next indication. Also review the example project for reproduction steps.