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CANDY-LINE / node-red-contrib-generic-ble

A Node-RED node set for providing access to generic BLE peripheral GATT characteristics.
Apache License 2.0
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Can't scan or connect to peripheral device without restarting Node-RED #49

Open contrabass22 opened 3 years ago

contrabass22 commented 3 years ago

Symptoms

  1. Checking "BLE Scanning" in a global Generic-BLE configuration node finds no devices after a long period of waiting. Unchecking, waiting a moment, and re-checking "BLE Scanning" exhibits the same behavior.
  2. Trying to connect to a peripheral device fails, and the nodes are in either the "error" or transition to the "missing" state.

Workaround Restart the Node-RED server. Subsequent attempts to scan or connect may succeed.

Details The following log occurred at the time of the failure:

[error] [GenericBLE:ERROR] Missing Bluetooth Object, Path:/org/bluez/hci0, Valid Paths:/org/bluez}, Error: Missing Bluetooth Object, Path:/org/bluez/hci0, Valid Paths:/org/bluez}
    at BluezBindings.init (/home/user/.node-red/node_modules/node-red-contrib-generic-ble/dist/noble/lib/bluez/noble/lib/bluez/bindings.js:182:19)
    at process._tickCallback (internal/process/next_tick.js:68:7)

Note that this issue can be compounded with #40 where even after restarting Node-RED may require the workaround of unchecking and/or checking "BLE Scanning" in the global configuration node to fix the issue.

Steps to Reproduce This is an intermittent issue. There don't seem to be any unusual aspects of a flow to get this to occur. I've seen it happen on flows with different devices. All of them have an inject node to connect to a peripheral device. The GATT characteristics they read/write don't seem to affect the behavior.

Component Versions Platform: Linux armv7l (32-bit) Bluez: 5.54 Node.js: v10.16.3 Node-red-contrib-generic-ble: 4.0.3 Node RED: v1.2.9

Hardware Bluetooth adapter: TPLINK UB400 Peripheral Device: TI Sensor Tag CC2650STK