Connect the Player GPIO

Owned by BrightSign TechDocs
Last updated: Sept 25, 2024
3 min read

BrightSign players have 12 total connections: eight GPIO connections for buttons or LEDs (or any combination of buttons or LEDs that adds up to eight); two for 3.3V power, and two for ground. The GPIO port requires a simple contact closure connection. For an explanation of the different GPIO button pins and grounds, consult the Hardware Interfaces documentation for your player model.

Each button/LED must be connected to a GPIO pin and to a ground. The Switch/LED connector is a DA15 Female, and allows the player to control external LEDs or other devices requiring 24mA of current or less.

You can use a 3rd Party Partner control board to connect more than eight buttons/LEDs, support higher voltage LEDs, or use other outputs.  

Connecting to an LED

To connect to an LED, you must connect the LED outputs to the LED anode and then connect the LED cathode to ground. If you want to connect another player, then the output is capable of sourcing or sinking up to 3.3V at 24mA, but there is a series resistor of 100Ω in each line. The connector also allows the connecting of external contact closures to the ground. 

To connect an LED to the player GPIO connector:

  1. Connect the anode of the LED to pin 8 (PWR), and cathode to pin 14 (GND).

    • The LED will be ON and will stay ON because pin 8 is always 3.3V and pin 14 is always GND. Use this to verify that the LED is working and that there is board power.

    • BrightSign players support 3.3V LEDs directly, without external power. 

    • We recommend using a 10-100 Ohm series resistor to protect the LED.

    • Once you wire the anode to pin 8 for testing, the LED anode is wired to a pin like the buttons.

  2. Connect the anode to pin 15 and leave the cathode connected to pin 14 (GND). You can now control the LED with a BrightAuthor:connected project, BrightAuthor project, or script.

  3. If the LED is too dim, remove the series resistor, as the board has an internal 100 ohm series resistor to limit current to the LED. 

Connecting to a Switch

To connect to a switch:

  1. Connect one side of the switch to the switch input

  2. Connect the other side of the switch to one of the ground pins on the DB15 connector

The connector can also supply 3.3V at up to 500mA to an external device. The 3.3V output is polyfuse-protected and can source up to 500mA. If one player is driving the inputs on another player, then you can drive at most three inputs from one output. The following calculations explain this limitation:

GPIO_Calculations_.png

The GPIO outputs have 100Ω series resistors; the GPIO inputs have 1K pull-up resistors to 3.3V; and the input threshold on the 541 chips is 2V high and .8V low. The high voltage is not problematic, but the low voltage can be if there are too many inputs connected to one output.

Examples

How to wire four buttons and four LEDs:

  • (20 KB)

How to wire three buttons and three LEDs:

  • (10 KB)

An example of a low-voltage button that only requires 3.3v for its LED:

  • (100 KB)