Arduino for STM32

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/* Reading Vdd and Temperature Sensor: http://stm32duino.com/viewtopic.php?f=3&t=1317#p16970
   Pito 8/2016
   Temperature sensor at ADC16, VREFINT at ADC17
   Sketch uses 21,772 bytes (17%) of program storage space. Maximum is 122,880 bytes.
   Global variables use 4,488 bytes of dynamic memory.
*/ 

void setup_vdd_tempr_sensor() {
    adc_reg_map *regs = ADC1->regs;
    regs->CR2 |= ADC_CR2_TSEREFE;    // enable VREFINT and Temperature sensor
    // sample rate for VREFINT ADC channel and for Temperature sensor
    regs->SMPR1 |=  (0b111 << 18);  // sample rate temperature
    regs->SMPR1 |=  (0b111 << 21);  // sample rate vrefint
    adc_calibrate(ADC1);
}

void setup(){
    setup_vdd_tempr_sensor();
    Serial.begin(115200);
    delay(1);
}

void loop() {
    float tempr, vdd;
    // reading Vdd by utilising the internal 1.20V VREF
    vdd = 1.20 * 4096.0 / adc_read(ADC1, 17);
    // following 1.43 and 0.0043 parameters come from F103 datasheet - ch. 5.9.13
    // and need to be calibrated for every chip (large fab parameters variance)
    tempr = (1.43 - (vdd / 4096.0 * adc_read(ADC1, 16))) / 0.0043 + 25.0;
    Serial.print("Vdd=  ");
    Serial.print(vdd);
    Serial.println(" V");
    Serial.print("Temp= ");
    Serial.print(tempr);
    Serial.println(" C");
    delay(500);
}

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static int32_t readVref()
{
#ifdef __LL_ADC_CALC_VREFANALOG_VOLTAGE
  return (__LL_ADC_CALC_VREFANALOG_VOLTAGE(analogRead(AVREF), LL_ADC_RESOLUTION)); //       VRef result more accurate
#else
  return (VREFINT * ADC_RANGE / analogRead(AVREF)); // ADC sample to mV                             //       like this
#endif
}

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#ifdef ATEMP
static int32_t readTempSensor(int32_t VRef)
{
#ifdef __LL_ADC_CALC_TEMPERATURE
  return (__LL_ADC_CALC_TEMPERATURE(VRef, analogRead(ATEMP), LL_ADC_RESOLUTION));     //         TempSensor results less accurate
#elif defined(__LL_ADC_CALC_TEMPERATURE_TYP_PARAMS)
  return (__LL_ADC_CALC_TEMPERATURE_TYP_PARAMS(AVG_SLOPE, V25, CALX_TEMP, VRef, analogRead(ATEMP), LL_ADC_RESOLUTION));  //   like this
#else
  return 0;
#endif
}
#endif

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VRef(mv)= 3366	Temp(°C)= 265	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 230
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 230
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 230
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 230
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 229
VRef(mv)= 3366	Temp(°C)= 266	A0(mv)= 230

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ADC internal channels

Available in core version greater than 1.5.0

analogRead() can now be used to read some internal channels with the following definitions:

    ATEMP: internal temperature sensor
    AVREF: VrefInt, internal voltage reference
    AVBAT: Vbat voltage

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VRef(mv)= 3294	Temp(°C)= 32	A0(mv)= 317
VRef(mv)= 3296	Temp(°C)= 32	A0(mv)= 315
VRef(mv)= 3296	Temp(°C)= 32	A0(mv)= 330
VRef(mv)= 3294	Temp(°C)= 32	A0(mv)= 329
VRef(mv)= 3294	Temp(°C)= 32	A0(mv)= 319
VRef(mv)= 3292	Temp(°C)= 33	A0(mv)= 324
VRef(mv)= 3301	Temp(°C)= 31	A0(mv)= 327
VRef(mv)= 3301	Temp(°C)= 31	A0(mv)= 313
VRef(mv)= 3296	Temp(°C)= 32	A0(mv)= 308
VRef(mv)= 3296	Temp(°C)= 32	A0(mv)= 309

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VRef(mv)= 3325	Temp(°C)= -8	A0(mv)= 886
VRef(mv)= 3325	Temp(°C)= -7	A0(mv)= 881
VRef(mv)= 3318	Temp(°C)= -7	A0(mv)= 882
VRef(mv)= 3327	Temp(°C)= -8	A0(mv)= 881
VRef(mv)= 3327	Temp(°C)= -8	A0(mv)= 884
VRef(mv)= 3325	Temp(°C)= -8	A0(mv)= 883
VRef(mv)= 3327	Temp(°C)= -8	A0(mv)= 883
VRef(mv)= 3325	Temp(°C)= -8	A0(mv)= 880
VRef(mv)= 3325	Temp(°C)= -8	A0(mv)= 886