Support Home Portal Log in
Open navigation

Dart3 - Connect an External Buzzer/LED

The Dart3 can be set to sound buzzers based on various conditions such as:

  1. A trip starting, but no driver ID has been scanned - to remind drivers to tag on. This is configured on the Driver ID parameter tab, see Immobiliser Install - Asset starts after valid Driver ID Scan [Dart3]
  2. Digital Inputs being active/inactive. This is configured on the Digital Input parameter tab, see Digital Inputs Introduction - Dart3
  3. Harsh driving events. Configured on the Harsh Driving parameter tab, see Harsh Event Setup - Dart3
  4. Speeding events. The buzzer will sound when going over a certain speed. Configured on the Speeding tab, see Speed Monitoring - Dart3
  5. When speeding inside a geo-fence - Geofence Downloads Example: Buzz when over 40km/h inside geofence

To have a buzzer sound, we need to do 2 things:

  1. Correctly wire the buzzer, and configure the right parameters to tell the device we have a buzzer connected
  2. Configure one of the options above to set under what conditions we want buzzing to occur. 

What we will cover below is how to set up the output to behave correctly to make a buzzer beep (i.e. beep, beep, beep). This is achieved by having the device toggle an output on/off. If we connected an LED instead of a buzzer - the LED would flash. So this concept can be extended to anything we might want to behave in a pulsing on/off manner. 

Buzzer Options

  1. The DM RFID reader also has an internal buzzer - no set up required - just plug and play for ultimate ease of install.
  2. We can configure digital outputs on devices to sound an external buzzer which we wire in. 

When we set the device to 'buzz' i.e. buzz on no driver ID - all options we have set up will buzz. If we had an RFID reader also connected that device's buzzer will sound at the same time. We don't need to do any special configuration for (1), so we will discuss 2.

Installation and Setup

Switched Ground as a Low Side Switch (preferred option)

The Dart3 has a switched ground output. See: Dart3 - Outputs - General for more detail. Switched Ground outputs can be thought of as a low side switch. They are high impedance (open circuit, no connection) when off, and provide a path to ground (i.e. close the loop) when on. 


  • Connect the high side of the buzzer to a constant power source - that is within the buzzers input voltage range. This could simply be to the vehicle battery, or to an ignition source (but then the buzzer is only provided with power when the ignition is on)
  • The low side of the buzzer to the switched ground output on the device. This is the Yellow Wire on the Dart3.

In this configuration, the buzzer is constantly powered, but the switched ground output going on/off has the effect of connecting and disconnecting the negative terminal to ground.

When the negative terminal is connected to ground (SW GND output on) there is a complete circuit, and the buzzer sounds.  


Digital output

Add the Digital Output 1 tab and set the function to "Buzzer"

Graphical user interface, text, application

Description automatically generated

 So now, if an event occurs that means the device will buzz (like over speed, or harsh braking) - the output line will pulse on, off, on, off, on, off... - to sound the buzzer. 

System Rail Output on High Side of Buzzer

This option is generally less preferable, as it means we must source a buzzer that is within the 3.5-5V, 500mA range (rating of output). However if we are already using the Switched Ground for another use (i.e. immobiliser) - it may be required. 

Pin 3 (Purple) is normally used to provide power to a DM RFID reader. Instead, we can cut the 4-way molex connector and connect it to the high side of a buzzer. 


  1. Connect the High Side of the buzzer to the Dart3 Purple Wire
  2. Connect the low side to Ground - Chassis ground or any of the black wires on the Dart3 harness can be used. 


Set the System Rail Output function to Buzzer

Now, when the device decides to 'Buzz' - the purple wire will pulse on and off.

Did you find it helpful? Yes No

Send feedback
Sorry we couldn't be helpful. Help us improve this article with your feedback.