#include <SPI.h>
#define CS 17
#define LDAC 16
SPISettings MCP4922(20000000,MSBFIRST,SPI_MODE0);
long lasttime1000ms = 0;
bool toogle = true;

void setup() {
  pinMode(CS,OUTPUT);
  pinMode(LDAC,HIGH);
  Serial.begin(115200);
}

void loop() {
  if(millis()-lasttime1000ms >= 1000){
    lasttime1000ms = millis();
    if(toogle == true){
      outDACA1V0();
      outDACB0V0();
    }else{
      outDACA0V0();
      outDACB1V0();
    }
    toogle = !toogle;
  }

}

void outDACA1V0(){
  SPI.begin();
  SPI.beginTransaction(MCP4922);
  digitalWrite(CS,LOW);
  SPI.transfer16(0x39B2); //OutA 2v
  delay(5);
  digitalWrite(LDAC,LOW);
  delay(5);
  digitalWrite(LDAC,HIGH);
  digitalWrite(CS,HIGH);
  SPI.endTransaction();
  Serial.println("A 2V On");
}

void outDACA0V0(){
  SPI.begin();
  SPI.beginTransaction(MCP4922);
  digitalWrite(CS,LOW);
  SPI.transfer16(0x3000);
  delay(5);
  digitalWrite(LDAC,LOW);
  delay(5);
  digitalWrite(LDAC,HIGH);
  digitalWrite(CS,HIGH);
  SPI.endTransaction();
    Serial.println("A 2V Off");
}

void outDACB1V0(){
  SPI.begin();
  SPI.beginTransaction(MCP4922);
  digitalWrite(CS,LOW);
  SPI.transfer16(0xBFFF); //OutA 1.8V
  delay(5);
  digitalWrite(LDAC,LOW);
  delay(5);
  digitalWrite(LDAC,HIGH);
  digitalWrite(CS,HIGH);
  SPI.endTransaction();
  Serial.println("B 3.3V On");
}

void outDACB0V0(){
  SPI.begin();
  SPI.beginTransaction(MCP4922);
  digitalWrite(CS,LOW);
  SPI.transfer16(0xB000);
  delay(5);
  digitalWrite(LDAC,LOW);
  delay(5);
  digitalWrite(LDAC,HIGH);
  digitalWrite(CS,HIGH);
  SPI.endTransaction();
  Serial.println("B 3.3V Off");
}