• MCU/module: SparkFun Pro Micro / ATmega32U4, U1
• Framework: Arduino AVR
• Interface to PC: native USB CDC serial used by DCS-BIOS
• Important: Exact DCS-BIOS control identifiers/addresses must be filled in for the specific Open Hornet panel configuration. The pin mapping below is grounded in the schematic.

Ini
[env:promicro]
platform = atmelavr
board = sparkfun_promicro16
framework = arduino
monitor_speed = 250000
lib_deps =
    dcs-bios/dcs-bios-arduino-library

Cpp
#define DCSBIOS_IRQ_SERIAL
#include <Arduino.h>
#include <DcsBios.h>

// Channel output pins from the schematic.
constexpr uint8_t COIL_CH1_PIN  = 2;
constexpr uint8_t COIL_CH2_PIN  = 3;
constexpr uint8_t COIL_CH3_PIN  = 4;
constexpr uint8_t COIL_CH4_PIN  = 5;
constexpr uint8_t COIL_CH5_PIN  = 6;
constexpr uint8_t COIL_CH6_PIN  = 7;
constexpr uint8_t COIL_CH7_PIN  = 8;
constexpr uint8_t COIL_CH8_PIN  = 9;
constexpr uint8_t COIL_CH9_PIN  = 10;
constexpr uint8_t COIL_CH10_PIN = 16;
constexpr uint8_t COIL_CH11_PIN = 14;
constexpr uint8_t COIL_CH12_PIN = 15;
constexpr uint8_t COIL_CH13_PIN = A0;
constexpr uint8_t COIL_CH14_PIN = A1;
constexpr uint8_t COIL_CH15_PIN = 1;   // TXO used as GPIO; DCS-BIOS uses native USB CDC
constexpr uint8_t COIL_CH16_PIN = 0;   // RXI used as GPIO; DCS-BIOS uses native USB CDC

constexpr uint8_t COIL_PINS[16] = {
  COIL_CH1_PIN, COIL_CH2_PIN, COIL_CH3_PIN, COIL_CH4_PIN,
  COIL_CH5_PIN, COIL_CH6_PIN, COIL_CH7_PIN, COIL_CH8_PIN,
  COIL_CH9_PIN, COIL_CH10_PIN, COIL_CH11_PIN, COIL_CH12_PIN,
  COIL_CH13_PIN, COIL_CH14_PIN, COIL_CH15_PIN, COIL_CH16_PIN
};

void setCoil(uint8_t channelIndex, bool enabled) {
  if (channelIndex >= 16) return;
  digitalWrite(COIL_PINS[channelIndex], enabled ? HIGH : LOW);
}

void allCoilsOff() {
  for (uint8_t i = 0; i < 16; i++) {
    digitalWrite(COIL_PINS[i], LOW);
  }
}

// Replace these callbacks with the actual DCS-BIOS export/control mapping.
// Example pattern: when DCS-BIOS says a magnetic hold should energize, call setCoil(channel, true).
void onMagHoldCh1Change(unsigned int newValue) { setCoil(0, newValue != 0); }
void onMagHoldCh2Change(unsigned int newValue) { setCoil(1, newValue != 0); }
void onMagHoldCh3Change(unsigned int newValue) { setCoil(2, newValue != 0); }
void onMagHoldCh4Change(unsigned int newValue) { setCoil(3, newValue != 0); }
void onMagHoldCh5Change(unsigned int newValue) { setCoil(4, newValue != 0); }
void onMagHoldCh6Change(unsigned int newValue) { setCoil(5, newValue != 0); }
void onMagHoldCh7Change(unsigned int newValue) { setCoil(6, newValue != 0); }
void onMagHoldCh8Change(unsigned int newValue) { setCoil(7, newValue != 0); }
void onMagHoldCh9Change(unsigned int newValue) { setCoil(8, newValue != 0); }
void onMagHoldCh10Change(unsigned int newValue) { setCoil(9, newValue != 0); }
void onMagHoldCh11Change(unsigned int newValue) { setCoil(10, newValue != 0); }
void onMagHoldCh12Change(unsigned int newValue) { setCoil(11, newValue != 0); }
void onMagHoldCh13Change(unsigned int newValue) { setCoil(12, newValue != 0); }
void onMagHoldCh14Change(unsigned int newValue) { setCoil(13, newValue != 0); }
void onMagHoldCh15Change(unsigned int newValue) { setCoil(14, newValue != 0); }
void onMagHoldCh16Change(unsigned int newValue) { setCoil(15, newValue != 0); }

// TODO: Replace these placeholders with actual DCS-BIOS IntegerBuffer declarations for the selected aircraft/panel.
// Example form only; addresses/masks/shift values must come from DCS-BIOS control-reference data:
// DcsBios::IntegerBuffer magHoldCh1Buffer(0x0000, 0x0001, 0, onMagHoldCh1Change);

void setup() {
  for (uint8_t i = 0; i < 16; i++) {
    pinMode(COIL_PINS[i], OUTPUT);
    digitalWrite(COIL_PINS[i], LOW);
  }

  DcsBios::setup();
}

void loop() {
  DcsBios::loop();
}

1. Upload firmware with the 28 V coil supply disconnected.
2. Confirm all outputs stay LOW after reset.
3. Test each output with a meter or LED before connecting ET coils.
4. Connect 28 V supply through a current-limited bench supply for first power-up.
5. Verify each channel energizes only when commanded by DCS-BIOS.

• Build: pio run -e promicro
• Flash: pio run -e promicro -t upload
• Monitor: pio device monitor -b 250000