Before you start:

  • Ensure your Dart is iButton capable. This should be on serial numbers newer than 122000
  • If you are using an LED, ensure there is a resistor in series. The DM harnesses should have a 1000 ohm resistor in series with both the brown and green wires.


Follow these steps to connect an iButton reader to the Dart.

  1. Cut off the 4 way Molex plug. Ensure you won't be using it with a Dart RFID reader first!
  2. Connect Brown (TTL Tx) and Green (TTL Rx) together. Connect both to the iButton readers signal line. On a DM reader, this is a red wire.
  3. Connect Black (TTL Gnd) to ground on the iButton reader. On a DM reader, this is a black wire.

The System Rail Output wire (Purple) can be used to flash an LED. If you wish to use the LED in the iButton harness, connect the following:
  1. Connect Purple (Sys Rail Out) to the LED positive wire. Ensure there is a resistor in series to protect the LED (These are already attached on DM readers). If using a DM reader, this is the brown wire for the RED LED, or green wire for the GREEN LED.
  2. Connect Black (TTL Gnd) to the LED negative. If using the DM reader, this is the yellow wire.