HD-4X4-HC ,4 Input & 4 High Current Drivers I/O Board
Features:
There is a terminal block for inputs (normally open switches). These 4 inputs are labeled 0-3 and correspond to BTN0-BTN3 BrightSign inputs.
There are high current drivers to drive lamps or LED panels. The external 12Volts and 0Volts is provided on the terminal blocks so that voltage can be supplied to external devices from the terminal block.
Outputs: Connect Loads between 'Output' and +V.
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When the BrightSign powers up is has pull-up resistors to the inputs (GPIO 0-7) which makes the signals high. As the BrightSign loads the software (which can take some time) this leaves the GPIO all high which would turn on the outputs. This design prevents this from happening. In the program, set the GPIO 4-7 to high and set to output. Then when you want an output to turn on, set that GPIO low and the inverter chip inverts the signal to a high in order to turn on the high current mosfet.
Note: Select a power supply with enough amps to handle your loads plus 20 milliamps for the board.
Author: Richard Harkey
Copyright © 2009 HMS Electronics. All rights reserved.
Revised: August 27, 2024