Si4703 programming

//To get the Si4703 inito 2-wire mode, SEN needs to be high and SDIO needs to be low after a reset
//The breakout board has SEN pulled high, but also has SDIO pulled high. Therefore, after a normal power up
//The Si4703 will be in an unknown state. RST must be controlled
void si4703_init(void) {
  Serial.println("Initializing I2C and Si4703");
  
  pinMode(resetPin, OUTPUT);
  pinMode(SDIO, OUTPUT); //SDIO is connected to A4 for I2C
  digitalWrite(SDIO, LOW); //A low SDIO indicates a 2-wire interface
  digitalWrite(resetPin, LOW); //Put Si4703 into reset
  delay(1); //Some delays while we allow pins to settle
  digitalWrite(resetPin, HIGH); //Bring Si4703 out of reset with SDIO set to low and SEN pulled high with on-board resistor
  delay(1); //Allow Si4703 to come out of reset

  Wire.begin(); //Now that the unit is reset and I2C inteface mode, we need to begin I2C

  si4703_readRegisters(); //Read the current register set
  //si4703_registers[0x07] = 0xBC04; //Enable the oscillator, from AN230 page 9, rev 0.5 (DOES NOT WORK, wtf Silicon Labs datasheet?)
  si4703_registers[0x07] = 0x8100; //Enable the oscillator, from AN230 page 9, rev 0.61 (works)
  si4703_updateRegisters(); //Update

  delay(500); //Wait for clock to settle - from AN230 page 9

  si4703_readRegisters(); //Read the current register set
  si4703_registers[POWERCFG] = 0x4001; //Enable the IC
  //  si4703_registers[POWERCFG] |= (1<<SMUTE) | (1<<DMUTE); //Disable Mute, disable softmute
  si4703_registers[SYSCONFIG1] |= (1<<RDS); //Enable RDS

#ifdef IN_EUROPE
    si4703_registers[SYSCONFIG1] |= (1<<DE); //50kHz Europe setup
  si4703_registers[SYSCONFIG2] |= (1<<SPACE0); //100kHz channel spacing for Europe
#else
  si4703_registers[SYSCONFIG2] &= ~(1<<SPACE1 | 1<<SPACE0) ; //Force 200kHz channel spacing for USA
#endif

  si4703_registers[SYSCONFIG2] &= 0xFFF0; //Clear volume bits
  si4703_registers[SYSCONFIG2] |= 0x0001; //Set volume to lowest
  si4703_updateRegisters(); //Update

  delay(110); //Max powerup time, from datasheet page 13
}

            PORTC.4 = 0    ; zou I2C I/O moeten zijn, maar dit werkt niet zo.
            LEDR = 1
            DelayMS 1000
            Rst = 1         ; Si uit reset
            LEDR = 1
            Repeat
            Until switch = 0  ; wachten tot SDA pin weer is losgelaten
            LEDR = 0
            LEDG = 1
            DelayMS 1000
            HBusIn %001000001, [ Radio[10], Radio[11], Radio[12], Radio[13], Radio[14], Radio[15], Radio[0], Radio[1], Radio[2], Radio[3], Radio[4], Radio[5], Radio[6], Radio[7], Radio[8], Radio[9] ]
            LEDG = 0
            DelayMS 1000
            Radio[7] = $8100       ; start osc
            HBusOut %001000000,[ Radio[2], Radio[3], Radio[4], Radio[5], Radio[6], Radio[7], Radio[8], Radio[9], Radio[10], Radio[11], Radio[12], Radio[13], Radio[14], Radio[15], Radio[0], Radio[1] ]
            LEDG = 1
            DelayMS 1000
            Radio[2] = $4001       ; enable
            HBusOut %001000000,[ Radio[2], Radio[3], Radio[4], Radio[5], Radio[6], Radio[7], Radio[8], Radio[9], Radio[10], Radio[11], Radio[12], Radio[13], Radio[14], Radio[15], Radio[0], Radio[1] ]
            LEDG = 0
            DelayMS 1000
            SetBit Radio[4],12     ; rds enable
            SetBit Radio[4],11      ; de-emph. europa
            ClearBit Radio[4],3       ; gpio
            ClearBit Radio[4],2       ;
            ClearBit Radio[4],1       ;
            SetBit Radio[4],0         ;
            
            SetBit Radio[5],4     ; europa spacing
            ClearBit Radio[5],3  ;
            ClearBit Radio[5],2       ;
            ClearBit Radio[5],1       ;
            SetBit Radio[5],0    ; Volume op bijna min
            HBusOut %001000000,[ Radio[2], Radio[3], Radio[4], Radio[5], Radio[6], Radio[7], Radio[8], Radio[9], Radio[10], Radio[11], Radio[12], Radio[13], Radio[14], Radio[15], Radio[0], Radio[1] ]
            LEDG = 1
            DelayUS 110