Matrix Orbital LCD2041 Legacy - Manual (Page 14)

Pin 4 Ground
Pin 3 SDA (1 2 C Data)
Pin 2 SLC (I 2 C Clock)
Pin 1 Vdc
Figure 15: Power Connector
2.4 General Purpose Output
The display has a general purpose output which can be used to control relays or other electronic devices.
This allows external devices to be turned on or off using your PC or controller and software commands. The
+ terminal is connected to the module positive supply, the - terminal is connected through a 240ohm current
limiting resistor and the electronic switch to ground.
Figure 16: General Purpose Output
Maximum allowable current is 20mA, which is enforced by the current limiting resistor. If the device
being switched has a resistance of 240ohms or more the corresponding resistor may be shorted. Solder a
small jumper wire or wirewrap wire between the two feed through holes.
Matrix Orbital LCD2041 11