Digital outputs are a simple ON/OFF type of signals that can be used to control annunciators, lights, relays, power lines, instrument flags - that is, all two-state output devices that are present in every aircraft cockpit.
Multiple LEDs can be combined into one “bargraph” indicator to display the value of a numeric parameter. You can get one of those LED bargraph indicators present on the market in different sizes, colors and sector numbers (see below on this page).
Note that some indicators in your cockpit do not require receiving any data from the simulator for their operation. Often this can be an indicator that only shows the current switch position/state (not the system state!) and can be directly controlled by this switch, as most "korry-type" push-button switches).
In the SimVimX system, from 1 to 8 74HC595 registers or from 1 to 4 DM13A LED drivers can be connected to one pin or to one MUX expansion output.
The every single LED consume quite a little power (10-50mA) itself but as you can have hundreds of LEDs in your cockpit, you must use powerfull dedicated source (+Vled +5V) for all LEDs in your system.
The amperage rate of this power supply must be sufficient to power all connected LEDs, for example, if one LED draws 20mA and you have 200 LEDs, the power supply must be rated at 4A, assuming they can all be lit at the same time.
You can use the same dedicated power supply for all 7-segment displays as well.
The SimVimX system uses 74HC595 registers as its primary option for controlling multiple LEDs. Buy ready-made 74HC595 expansion boards, which are available in several versions on the market.
You will also need resistors - one for each LED, connected in series to the board outputs.
In addition, any of these boards can be used for seven-segment indicators.
This DM13A LED driver is used in SimVimX System to provide multiple digital outputs (16 LEDs, relay, etc. for one driver). This IC is a register with a latch for 16 constant current LED outputs. Other similar drivers can be used too.
All driver ICs listed below are similar in functionality and pin mapping, so you can use any of them that are easier to get for you.
Some of these ICs have DIP casing (DM13A, DM134, ST2221C), others may have SOP24 casing. But this is not a problem, using them is not so difficult with the cheap SOP28 adapter.
LED CONTROL OPTIONS
74HC595 Shift Registers DM13A LED Drivers MAX7219 LED Matrix MUX for LED Drivers LED Bar Graph Indicator Direct Connection LED Configuration
