External notification plugin issues

Support
1

I cannot get external notif plugin to work properly. I’ve connected a buzzer positive to gpio13 and buzzer negative to GND. In this case ext_notification_plugin_active config should be set to TRUE ? Setup is:
ext_notification_plugin_enabled: True
ext_notification_plugin_alert_message: True
ext_notification_plugin_active: TRUE
ext_notification_plugin_output_ms: 1500
ext_notification_plugin_output: 13

I know there was bug #1040 reported, but I have trouble understanding a workaround. "This is a workaround that fixes #1040.
In this naive solution packets are accepted for plugins having a boundChannel, when the channel of the packet is actually empty (or doesn’t have channel specified at all).
Please consider, that this might not be the goal of the channel-binding of a plugin. See #1040 for details!"

What is boundChannel and channel binding ? Should a channel name be a specific name in order for this plugin to work ?

2

Are you sure you have an active buzzer and not passive?
Have you tried an LED?
Does the buzzer beep if you just wire it to the battery?

3

Yes, I have active buzzer, I’ve connected it directly to 3.3v and it works.

4

What is the version of the firmware you used? If you used 1.3.x, the command syntax had been changed.

You may try following commands:
https://uniteng.com/wiki/doku.php?id=meshtastic:nano#enabling_ext_notification_plugin

5

I’m using Heltec SX1276 v2 board and firmware 1.2.65 since 1.3x is not working properly with my board.

6

In my design, I used a transistor to drive the active buzzer due to the active buzzer generally requiring 30mA - 50mA to beep. The typical max source current of the ESP32’s IO is 40mA.

If you have a multi meter, you may connect a 10k-100k resistor between IO13 and GND, and measure the voltage when receiving message, a high level pulse is expected.

If you don’t see a high level pulse , it means a firmware or setting problem. Otherwise, the current provided by the IO is not enough to drive the active buzzer.

Neil

7

Where should I put the multimeter leads when using resistor ? I tried that before but without resistor - postive lead to GPIO13 and negative to GND. I got zero voltage on GPIO13. Some pins were high so assume I used the correct method.

8

Using the multimeter same as without the resistor, you should see the voltage goes to about 3.3V from 0V for about 1500ms.