Receiver sleep mode RDA5807M
Switch off:
reg02h = reg02h &amp; ~RDA5807M_FLG_ENABLE;
setRegister(RDA5807M_REG_CONFIG, reg02h);

Switch on:
reg02h = reg02h | RDA5807M_FLG_ENABLE;
setRegister(RDA5807M_REG_CONFIG, reg02h);

EDIT: (to answer a comment of Антон)
Nastroika (настройка) means &quot;tuning&quot;. Is that right? Then I would use this method only for tuning. Create two methods one for switching off and one for switching on.
void switchOff()
{
   reg02h = reg02h &amp; ~RDA5807M_FLG_ENABLE;
   setRegister(RDA5807M_REG_CONFIG, reg02h);
}

void switchOn()
{
   reg02h = reg02h | RDA5807M_FLG_ENABLE;
   setRegister(RDA5807M_REG_CONFIG, reg02h);
}

In the Nastroika Method you should only perform the tuning and let the module of. If you insist to switch on at the same time you could use your old version.
Example:
void Nastroika(uint8_t volume, uint16_t freq) 
{
   // !!!!! This is the wrong place for Wire begin
   // move it to the setup method.
   // Wire.begin();
   reg02h = reg02h | RDA5807M_FLG_DHIZ | RDA5807M_FLG_DMUTE;
   // or if you insist / you want to keep the module be started here
   // reg02h = reg02h | RDA5807M_FLG_ENABLE | RDA5807M_FLG_DHIZ | RDA5807M_FLG_DMUTE;
   setRegister(RDA5807M_REG_CONFIG, reg02h);
   reg03h = (freq - 870) &lt;&lt; RDA5807M_CHAN_SHIFT; 
   setRegister(RDA5807M_REG_TUNING, reg03h | RDA5807M_FLG_TUNE);

   reg05h = getRegister(RDA5807M_REG_VOLUME); 
   reg05h &amp;= ~RDA5807M_VOLUME_MASK;
   reg05h |= volume &lt;&lt; RDA5807M_VOLUME_SHIFT;
   setRegister(RDA5807M_REG_VOLUME, reg05h);
}

Usage:
void setup() 
{
   Serial.begin(9600);
   Wire.begin();
   Nastroika(4, 1077); 
}

void loop() 
{
  switchOff();
  delay(5000);
  switchOn();
  delay(5000);
}