A solar powered temperature and humidity monitor using ATtiny85 microcontroller and SHT31 sensor. Displayed on a four digit LCD

attiny85-satellite-lcd.cpp

//
// Project link: https://www.bhoite.com/sculptures/satellite-2202/
//
#include "Adafruit_SHT31.h"
//#include <TinyWireM.h>
//#include <USI_TWI_Master.h>
#include <avr/sleep.h> //Needed for sleep_mode
#include <avr/wdt.h> //Needed to enable/disable watch dog timer
//Following is the header file for the LCD module bought on ebay
//Seller link https://www.ebay.com/itm/284843842249
//Information on the LCD http://www.hexpertsystems.com/LCD/
#include <cdm4101.h> 

int ctr=1000;
CDM4101 LCD;
char data[25];
int temperature = 0;

bool displayToggle = 0;
uint8_t loopCnt = 0;

Adafruit_SHT31 sht31 = Adafruit_SHT31();

void setup() 
{
  pinMode(3, INPUT_PULLUP);
  pinMode(4, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(1, INPUT_PULLUP);
  ADCSRA &= ~(1<<ADEN); //Disable ADC, saves ~230uA
  // put your setup code here, to run once:
  //TinyWireM.begin();
  Wire.begin();
  sht31.begin(0x44);
  LCD.Init();
  LCD.DispStr("sat6");
  delay(1000);
  set_sleep_mode(SLEEP_MODE_PWR_DOWN); //Power down everything, wake up from WDT
  sleep_enable();
}

//This runs each time the watch dog wakes us up from sleep
ISR(WDT_vect) {
  //watchdog_counter++;
  displayToggle=!displayToggle;
}

void loop() 
{
  setup_watchdog(9); //Setup watchdog to go off after 8sec
  sleep_mode(); //Go to sleep! Wake up 8 sec later
  
  int temperature = (sht31.readTemperature()*1.8)+32;
  //int temperature = sht31.readTemperature();
  int humidity = sht31.readHumidity();
  if (displayToggle)
  {
  //insure that the temperature is in a valid range
    if ((temperature <110) && (temperature > -20))
    {
      sprintf(data,"%doF",temperature);
      LCD.DispStr(data);
    }
  }

  else
  {
  //insure that the humidity is in a valid range
    if ((humidity <101) && (humidity > 0))
    {
      sprintf(data,"%drH",humidity);
      LCD.DispStr(data);
    }
  }
}

//Sets the watchdog timer to wake us up, but not reset
//0=16ms, 1=32ms, 2=64ms, 3=128ms, 4=250ms, 5=500ms
//6=1sec, 7=2sec, 8=4sec, 9=8sec
//From: http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/
void setup_watchdog(int timerPrescaler) {

  if (timerPrescaler > 9 ) timerPrescaler = 9; //Limit incoming amount to legal settings

  byte bb = timerPrescaler & 7; 
  if (timerPrescaler > 7) bb |= (1<<5); //Set the special 5th bit if necessary

  //This order of commands is important and cannot be combined
  MCUSR &= ~(1<<WDRF); //Clear the watch dog reset
  WDTCR |= (1<<WDCE) | (1<<WDE); //Set WD_change enable, set WD enable
  WDTCR = bb; //Set new watchdog timeout value
  WDTCR |= _BV(WDIE); //Set the interrupt enable, this will keep unit from resetting after each int
}

cdm4101.cpp

//----------------------------------------------------------------------------

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "Arduino.h"

#include "Wire.h"

#include "cdm4101.h"

//----------------------------------------------------------------------------

#define I2C_ADDR	(0x38)

#define CMD_MODE_SET	0xCD
#define CMD_LOAD_DP		0x80
#define CMD_DEVICE_SEL	0xE0
#define CMD_BANK_SEL	0xF8
#define CMD_NOBLINK		0x70
#define CMD_BLINK		0x71

#define DASH            10
#define UNDERSCORE      11
#define SPACE           12
#define ASTERISK        39
#define ALPHA_START     13

#define HOLD_TIME   8

//----------------------------------------------------------------------------

static byte const Segs[] =
{
	0x6F, // 0x30 0
	0x03, // 0x31 1
	0x5D, // 0x32 2
	0x57, // 0x33 3
	0x33, // 0x34 4
	0x76, // 0x35 5
	0x7E, // 0x36 6
	0x43, // 0x37 7
	0x7F, // 0x38 8
	0x77, // 0x39 9
	0x10, //  -
	0x04, //  _
	0x00, //  space
	0x7B, // A
	0x3E, // b
	0x6C, // C
	0x1F, // d
	0x7C, // E
	0x78, // F
	0x77, // G
	0x3B, // H
	0x02, // i
	0x0F, // J
	0x38, // K - can't do
	0x2C, // L
	0x5A, // M - can't do
	0x1A, // n
	0x6F, // O
	0x79, // P
	0x75, // Q - can't do
	0x18, // r
	0x76, // S
	0x3C, // t
	0x0E, // u
	0x2F, // V - can't do
	0x4E, // W - can't do
	0x2B, // X - can't do
	0x37, // y
	0x5D, // Z
	0x71, // ° - use * to represent it in your string
};

//----------------------------------------------------------------------------

void CDM4101::Update(void)
{
	byte data[5]; // bytes to send display segments

	if(Ctr)
	{
		Ctr--;
		return;
	}

	Wire.beginTransmission(I2C_ADDR);
	Wire.write(CMD_MODE_SET);
	Wire.write(CMD_LOAD_DP);
	Wire.write(CMD_DEVICE_SEL);
	Wire.write(CMD_BANK_SEL);


	if(Blink) Wire.write(CMD_BLINK);
	else      Wire.write(CMD_NOBLINK);

#if 1
	data[0] = (Digits[0] >> 4); // || LCD_BAR
	data[1] = (Digits[0] << 4) | (Digits[1] >> 3);
	data[2] = (Digits[1] << 5) | (Digits[2] >> 2);
	data[3] = (Digits[2] << 6) | (Digits[3] >> 1);
	data[4] = (Digits[3] << 7);
#else
	Wire.write(0x70);
	Wire.write(0x3B);
	Wire.write(0xB5);
	Wire.write(0xD9);
	Wire.write(0x80);
#endif

	for(int i=0;i<5;i++) Wire.write(data[i]);

	Wire.endTransmission();
}

//----------------------------------------------------------------------------

void CDM4101::Init(void)
{
	Blink = 0;

	Digits[0] = Segs[SPACE];
	Digits[1] = Segs[SPACE];
	Digits[2] = Segs[SPACE];
	Digits[3] = Segs[SPACE];

	Wire.beginTransmission(I2C_ADDR);
	Wire.write(CMD_MODE_SET);
	Wire.write(CMD_LOAD_DP);
	Wire.write(CMD_DEVICE_SEL);
	Wire.write(CMD_BANK_SEL);
	Wire.write(CMD_NOBLINK);
	Wire.write(0x05);
	Wire.write(0xD5);
	Wire.write(0x9B);
	Wire.write(0xFF);
	Wire.write(0x00);

	Wire.endTransmission();

	Ctr = 0;
}

//----------------------------------------------------------------------------

void CDM4101::Command(byte cmd)
{
	switch(cmd)
	{
		case CDM4101_BLINK_OFF :
			Blink = 0;
			Update();
			break;

		case CDM4101_BLINK_ON :
			Blink = 1;
			Update();
			break;

		case CDM4101_CLEAR :
			Digits[0] = Segs[SPACE];
			Digits[1] = Segs[SPACE];
			Digits[2] = Segs[SPACE];
			Digits[3] = Segs[SPACE];

			Update();
			break;

		default :
			break;
	}
}

//----------------------------------------------------------------------------

char CDM4101::ConvertChar(char c)
{
	if((c >= 'a') && (c <= 'z')) c = c - 'a' + ALPHA_START;
	else
		if((c >= 'A') && (c <= 'Z')) c = c - 'A' + ALPHA_START;
		else
			if((c >= '0') && (c <= '9')) c = c - '0';
			else
				if(c == '-') c = DASH;
				else
					if(c == '_') c = UNDERSCORE;
					else
						if(c == '*') c = ASTERISK;
						else c = SPACE;
	return c;
}

//----------------------------------------------------------------------------

void CDM4101::DispChar(byte index, char c)
{
	Digits[(int)index] = Segs[(int)(ConvertChar(c))];
	Update();
}

//----------------------------------------------------------------------------

void CDM4101::DispStr(char *s)
{
	byte i,c;

	for(i=0;i<CDM4101_NUM_DIGITS;i++) Digits[i] = Segs[SPACE];

	i = 0;

	while((i < 4) && s[i])
	{
		c = Segs[(int)(ConvertChar(s[i]))];

		Digits[i] = c;
		i++;
	}

	Update();
}

//----------------------------------------------------------------------------

void CDM4101::DispStrTimed(char *s)
{
	DispStr(s);
	Ctr = HOLD_TIME;
}


//----------------------------------------------------------------------------
// display a decimal value, right justified.

void CDM4101::DispDec(short n)
{
	byte i;
	char  str[5];

	if(n < -999L) n = -999L;
	if(n > 9999L) n = 9999L;

	for(i=0;i<5;i++) str[i] = 0;

	itoa(n, str, 10);

	while(str[3] == 0)
	{
		for(i=3;i>0;i--) str[i] = str[i-1];
		str[0] = ' ';
	}

	DispStr(str);
}

//----------------------------------------------------------------------------

cdm4101.h

#ifndef _CDM4101_H_
#define _CDM4101_H_

#include <inttypes.h>

//----------------------------------------------------------------------------

#define CDM4101_NUM_DIGITS  4

//----------------------------------------------------------------------------
// LCD commands.

#define CDM4101_BLINK_OFF 6
#define CDM4101_BLINK_ON  7
#define CDM4101_CLEAR     8

//----------------------------------------------------------------------------

class CDM4101
{
public:
	void Init(void);
	void Command(byte cmd);
	void DispChar(byte index, char c);
	void DispStr(char *s);
	void DispStrTimed(char *s);
	void DispDec(short n);

private:
	void Update(void);
	char ConvertChar(char c);

	byte Digits[CDM4101_NUM_DIGITS];
	byte Blink;
	byte Ctr;
};

//----------------------------------------------------------------------------

#endif // _CDM4101_H_

Problem programming Arduino sketch.

• error: 'setup_watchdog' was not declared.....any help will be apreciated