BrightSign 4K242 Hardware - Manual (Page 15)

BrightSign 4K242, 4K1042, 4K1142
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All information provided in this reference manual applies to products under development. The characteristics and specifications of these products are subject to
change without notice. BrightSign assumes no obligation regarding future manufacturing unless otherwise agreed to in writing. © BrightSign LLC, 2015
Note: The GPIO outputs have 100 Ω series resistors; the GPIO inputs have 1K pullup 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.
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)
The following table illustrates the pinout of the DA15 on the 4K series of players:
pin Description pin Description
1 IR blaster input 2 Ground
3 Button 6 I/O 4 Button 5 I/O
5 Button 3 I/O 6 Ground
7 Button 1 I/O 8 +3.3V output at 500mA
9 Ground 10 Button 7 I/O
11 Ground 12 Button 4 I/O
13 Button 2 I/O 14 Ground
15 Button 0 I/O -- --