Svenska ElektronikForumet

Kod: Markera allt

/*
//Battery voltage VBAT-|39k|--ADC--|10k|---GND  (P2, ADC1, 24.5v->5v, ADC*24X ~50mV error ~0.2%)
//Battery detection                             (P4, ADC2)
//  Use internal pull-up to get a resistor divider..
//  400...1023  --> open detection
//  176...399   --> 18.0V battery, 5Lipo cells
//  50....175   --> 14.4V battery, 4Lipo cells
//  0.....50    --> short detection
*/


#include <SoftSerial.h>
#include <stdint.h>
#include <avr/wdt.h>

#define BATTERY_TYPE_UNKNOWN  0
#define BATTERY_TYPE_14V4     1
#define BATTERY_TYPE_18V      2

SoftSerial debugSerial(1, 1);
uint8_t battery_type = BATTERY_TYPE_UNKNOWN;

/*
 * @brief Read analog input, mean filter with 64 values..
 */
uint16_t analog_read(uint8_t ch){
  uint16_t val=0;

  //take 64 samples
  for(int i=0;i<64;i++){
    val += analogRead(ch);
  }
  val /= 64;

  return val;
}


uint8_t detect_battery(void){
  uint16_t adc = analog_read(2);
  uint8_t type=BATTERY_TYPE_UNKNOWN;

  
  if( (adc <= 400) && (adc >= 176)){
    type = BATTERY_TYPE_18V;
  }

  if( (adc <= 175) && (adc >= 50)){
    type = BATTERY_TYPE_14V4;
  }

  return type;
}

/**
 * @brief Get battery voltage
 */
uint16_t read_battery_voltage(void){
  uint16_t battery_voltage = analog_read(1)*24U;

  /* Calibration value(mV) */
  battery_voltage -= 150;
  
  return  battery_voltage;
}

void shutdown(void){
  digitalWrite(0, HIGH);
}



// the setup function runs once when you press reset or power the board
void setup() {
  /* if WDT reset occur, shutdown directly */
  if(MCUSR & (1<<WDRF)){
    pinMode(0, OUTPUT);
    digitalWrite(0, HIGH);
  }
  
  wdt_disable();
  wdt_reset();
  wdt_enable(WDTO_4S);

  // initialize digital pin 13 as an output.
  pinMode(0, OUTPUT);       /* Shutdown pin */
  pinMode(1, OUTPUT);       /* Debug output/led */
  pinMode(2, INPUT);        /* Battery voltage */
  pinMode(3, INPUT);        /* not used */
  pinMode(4, INPUT_PULLUP); /* Battery type, use pull-up as analog divider */

  debugSerial.begin(9600);
  debugSerial.txMode();

  battery_type = detect_battery();
}

void debug(void){
  uint16_t detect_adc = analog_read(2);
  uint16_t battery_voltage = analog_read(1)*24U;
  
  debugSerial.println(F("Debug: "));
  debugSerial.println(detect_adc);
  debugSerial.println(battery_voltage);
  
  if(battery_type == BATTERY_TYPE_18V){
    debugSerial.println(F("Battery type 18V"));
  }else if(battery_type == BATTERY_TYPE_14V4){
    debugSerial.println(F("Battery type 14V4"));
  }
  
  debugSerial.println("");
}

// the loop function runs over and over again forever
void loop() {
  uint16_t vbat = read_battery_voltage();
  uint16_t min_vbat=0xFFFF;

  if(battery_type == BATTERY_TYPE_UNKNOWN){
    debugSerial.println(F("Unknown battery, shutdown"));
    shutdown();
  }
  
  //5 cells battery
  if( (battery_type == BATTERY_TYPE_18V) && (vbat < (3400*5))){
    debugSerial.println(F("Low battery, shutdown"));
    shutdown();
  }

  //4 cells battery
  if( (battery_type == BATTERY_TYPE_14V4) && (vbat < (3400*4))){
    debugSerial.println(F("Low battery, shutdown"));
    shutdown();
  }

  wdt_reset();
  delay(1000);
  debug();                  //some debug output
  
}