This section describes the characteristics and operation of all connectors on the HD225 and HD1025.
Power Connector
The power connector for the HD225 and HD1025, which connects the power cord to the device, is rated for 12V@3A. It uses a locking connector to prevent inadvertent disconnections.
3.5mm Audio Connector
The HD225 and HD1025 have a dedicated 3.5mm stereo audio port and a combination analog/optical audio jack. To transmit a digital audio signal, use an optical audio cable. Analog and digital audio cannot be transmitted simultaneously. Dolby audio is supported as a paid license.
The full-scale voltage output of the analog audio is 2V RMS. The minimum load impedance is 32Ω.
The analog audio connector has the following pinout:
- Tip: Left audio
- Ring: Right audio
- Sleeve: Ground for audio signal
3.5mm IR Input/Output
The IR blaster generates or receives a space-encoded NEC or Pronto Hex signal. RC5 encoding is also supported. The two transported bit values of the signal (0 and 1) are encoded using differing lengths of low-time IR pulses.
The 3.5mm IR in/out port has the following pinout:
- Tip: 3V@50mA
- Ring: IR Input
- Sleeve: IR Output
The sleeve is used as a ground during input operations. |
3.5mm Serial
The HD1025 contains an UART (asynchronous serial) interface. It is a 3.5mm (1/8") jack that connects a serial modem or other devices that use a serial connector, and it uses TTL for communication. The receiver will tolerate input voltages between -30V and +30V, with anything below 3V interpreted as a logical 1. The transmitter drives +5V for logical 0 and 0V for logical 1.
The default baud rate of the interface is 115200, with no parity, 8 data bits, and 1 stop bit. These settings can be configured in the software. The serial interface supports TX, RX, and ground only—RTS/CTS hardware flow control is not supported. The following diagram illustrates the behavior of the TX and RX signal:
The 3.5mm serial port has the following configuration (from the perspective of the player):
- Tip: Transmit
- Ring: Receive
- Sleeve: Ground
BrightSign players are DTE devices, so communication with another DTE device that uses a 3.5mm port would require a null-modem cable or converter that transposes the TX/RX signals. If the device communicating with the player uses a DE9 serial port, the serial cable should be wired as shown in the following diagram:
GPIO
The HD225 and HD1025 have a 12-pin GPIO switch and LED connector, which allows the player to control external LEDs or other devices requiring 24mA of current or less.
The GPIO port is a standard design manufactured by Phoenix Contact, Wurth Electronics, and others. Pluggable GPIO terminal blocks can be inserted into the GPIO connector to make bare-wire contacts (see here for an example part). These terminal blocks can be purchased from the BrightSign Store. If you wish to source your own terminal blocks, make sure to use 4-pin or 6-pin blocks (12-pin blocks are extremely difficult to remove from the GPIO port).
Connect the LED outputs to the LED ANODE and connect the LED CATHODE to the ground. If you want to connect another device, 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 GPIO also allows for connecting of external contact closures to the ground. In order to connect a switch, connect one side of the switch to the switch input, and connect the other side to one of the ground pins on the GPIO 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 BrightSign player is driving the inputs on another BrightSign player, then you can drive at most three inputs from one output. The following calculations explain this limitation:
The GPIO outputs have 100Ω series resistors; the GPIO inputs have 1K pullup resistors to 3.3V; and the input threshold 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.
1 out driving 1 in | V=3.3*100/(100+1,000)=0.3 |
1 out driving 2 in | V=3.3*100/(100+500)=0.55 |
1 out driving 3 in | V=3.3*100/(100+333.3)=0.76 |
1 out driving 4 in | V=3.3*100/(100+250)=.94 (This is too high, so 1 output driving 3 inputs is the maximum) |
GPIO Pinout
The following table illustrates the pinout of the GPIO on the HD225 and HD1025:
| Pin | Function | Pin | Function |
|---|---|---|---|
| 1 | GND | 7 | GND |
| 2 | 3.3V | 8 | 3.3V |
| 3 | BUTTON 0 | 9 | BUTTON 4 |
| 4 | BUTTON 1 | 10 | BUTTON 5 |
| 5 | BUTTON 2 | 11 | BUTTON 6 |
| 6 | BUTTON 3 | 12 | BUTTON 7 |
The following schematic illustrates the pinout of the GPIO connector:
LAN/Ethernet
This connection is used to connect an ethernet cable for internet access. The HD225 and HD1025 wired ethernet connection is capable of 10/100/1000 Mbps. The maximum length for Cat 5E cable is 100 meters; the allowed length can be higher or lower depending on the quality of the cable.
USB
The HD1025 has one USB-A 2.0 port to connect USB-compatible devices. This device provides 5V 1A over each USB port for peripheral devices.
HDMI Output
The HDMI®-out connector on the HD225 and HD1025 is used to send digital video and audio to HDMI-enabled sink devices. CEC control and AVI are supported over each HDMI interface independently, and it can maintain the configured multiscreen layout if one of the HDMI outputs loses sync.
WiFi Antenna Connectors
The HD225 and HD1025 have a two SMT type SMA connectors and an M.2 connector to allow easy installation of external WiFi antennas. Both devices contain an internal M.2 PCIe card that enables WiFi/Bluetooth.