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EEL 4924 Electrical Engineering Design 2(Senior Design)
Final Design Report23 April 2013
Project Title: Interactive BreakerBox
Team Members:Name: Ambrose Coulliette Name: Aaron Joseph
Project Abstract:The goal of our project is to measure the power consumed by three individual breaker
circuit by calculating the RMS voltage and currents for each one. This information is
displayed on a LCD screen mounted on the breaker box front panel and sent wirelessly to
a computer to be shown on a python GUI display. The GUI can also displays KWh and cost
associated with each breaker circuit and has the ability to send command to turn a circuit
on and off. A smartphone can remotely access the GUI.
1
Table of Contents Page(s)
Project Abstract 1
Project Features 3
Components 5
Hardware 7
Distribution of Labor 14
Projected Timeline 15
Conclusion 15
Appendix A 16
Appendix B 23
Appendix C 31
List of Tables
1. BOM (bill of materials) 14
2. Distribution of Labor 14
List of Figures
1. LCD screen 3
2. Python GUI 4
3. GUI access by smart phone 4
4. LCDNHD0420AZFSWGBW33V3 5
5. XBeeXB24AWI001ND 5
6. Split Core Current Transformer ECS1030L72 6
7. RelayT9AS1D125 6
8. Project layout 7
9. Sensor and control layout 7
10. Typical current sensor schematic 8
11. Current sensor experiment results 8
12. Voltage sensor 9
13. Other component schematics 10
14. Main PCB 11
15.Relay schematic 12
16. Relay PCB 13
17. Gantt Chart of Timeline 15
2
Project FeaturesThe following are our projects features:
Measure power consumed by three breaker circuits (see appendix B) by
Calculate RMS current : ( ) / R input from noninvasive current transformer see figure 6
Calculate RMS voltage: input from transformer connected in parallel to circuits
LCD screen displays (see appendix B)
RMS currents
RMS voltage
Power
Figure 1: LCD screen
Wirelessly send data to a computer via XBee (see appendix B)
RMS currents
RMS voltage
Python GUI (see appendix A)
Displays
RMS currents
RMS voltage
Powers
KWh
Cost
Relay commands
Turn circuit on
Turn circuit off
3
Figure 2: Python GUI
Python GUI access by smart phone
VNC (software connection)
Server
Client
password protection
Figure 3: GUI access by smart phone
4
ComponentsThe following are the main components we have chosen :
NHD0420AZFSWGBW33V3 Character Liquid Crystal Display Module shown
in figure 4.
This model was chosen because it has 4 lines and can display 20 characters
per line, which will be more than enough to display the real time power usage
for each of the three breaker circuits
The backlight is powered with 3V and the reference voltage is 3.3V this
means that its power consumption is relatively low.
We have used a similar LCD before in other classes which were very simple
to use
Figure 4: NHD0420AZFSWGBW33V3
XB24AWI001ND XBee model shown in figure 5
This model was chosen because it was the cheapest XBee that met our
project needs
There are lots of tutorials on how to use this model online
There is a 30m range of communication for this series 1 model
Figure 5: XB24AWI001ND
Split Core Current Transformer ECS1030L72 model shown in figure 6
5
This component was chosen because it can be used to measure AC current
at 50/60 Hz
It was cheap
It mounts easily
It has a linear relationship between primary current and output voltage
Figure 6: Split Core Current Transformer ECS1030L72
Atmega164PA microcontroller
This microcontroller was chosen because we got free samples
It is easy to program
Contains an appropriate number of ADC and i/o pins
T9AS1D125 Power Relays model shown in figure 7
The model was chosen because it has a rated current of 30A
It is rated for a switching Voltage max of 277VAC
It has a coil Voltage of 5VDC
Figure 7: T9AS1D125
6
HardwareOverall project layout:
The overall project layout is shown in figure 8. Components inside of the green rectangular
boundary indicates components placed inside the breaker box; therefore, housed inside
the breaker box are the LCD, uP, one XBee, current sensors and the voltage sensor.
Figure 8: Project layout
Sensors and control layout:
The sensors and control layout shown in figure 9 gives an indication of how the voltage
sensor input, current sensor inputs and relay circuits were implemented. Each circuit has a
mechanical breaker switch much like a traditional breaker box, a relay circuit which acts
like a switch that can be controlled by our microcontroller, and a current transformer which
serves as the input to a current sensor. The voltage sensor input which is a transformer, is
placed in parallel to the circuits.
Figure 9: Sensor and control layout
7
Current sensors:
A typical current sensor schematics is shown in figure 10. The input to the current sensor is
a current produced by the current transformer. This current flows through a resistor. The
voltage across the resistor is rectified. The rectified voltage servers as an input to an ADC
pin on our microcontroller. The rectified voltage makes it possible to have only positive
voltages and better resolution than other techniques when calculating the RMS values.
Figure 10: Typical current sensor schematic
In order to test the accuracy of the current sensor some experiments were performed. The
results of these experiments over two periods are shown in figure 11.
Figure 11: Current sensor experiment results
8
Voltage sensor:
The voltage sensor schematic is shown in figure 12. The secondary voltage of the
transformer serves as an input to a voltage divider circuit. Much like the current sensor
circuit the output of the voltage divider circuit is rectified then the rectified voltage serves as
an input to an ADC pin on our microcontroller.
Figure 12: Voltage sensor
Other circuits:
Figure 13 shows the schematics for the other components implemented in the main PCB.
These other component are 3.3V and 5V regulator, XBee, ATmega164PA, and LCD.
9
Figure 13: Other component schematics
10
Main PCB:
The main PCB shown in figure 14 is made of current sensors, voltage sensor, and other
components schematics shown in figure 13 .
Figure 14: Main PCB
Relay schematics:
The relay schematic is shown in figure 15.To control power to each circuit relays were
used. As the micro controller can’t supply enough current to operate the relay a transistor is
used as a switch. There is no polygon pour in Figure 16 on the right side of the PCB to
prevent high currents up to 15 amps from arching.
11
Figure 15: Relay schematic
12
Figure 16: Relay PCB
13
B.O.M.:
The following table shows the bill of materials used in constructing this project. It also gives
an estimated cost ($319.78) for replicating this project.
Table 1: BOM (bill of materials)
Distribution of LaborThe following table shows the breakdown of each team member's projected labor by
approximate percentage.
Table 2: Distribution of Labor
14
Projected TimelineThe following is a Gantt chart of the projected timeline for the project in figure 6.
Figure 17: Gantt Chart of Timeline
ConclusionThis project measures the power consumed by three breaker circuit by calculating the RMS
voltage and current for each one. That information is displayed on a LCD screen and sent
wirelessly to a computer to be displayed on a python GUI. The GUI also displays KWh and
cost associated with each circuit, it can also send commands to turn a circuit on and off.
The GUI can be remotely accessed by a smartphone.
This project is prelude to a tool that residential power consumers can use to conserve
power through selfawareness, observe appliance normal power consumption, and offer a
convenient way to turn appliances on and off while away from home.
15
Appendix APython GUI program:
#!/usr/bin/python# * coding: iso88591 *
########################################################### Interactive BreakerBox GUI ## Composers: Ambrose Coulliette, Aaron Joseph ## Last update: 4/20/13 ###########################################################import Tkinterimport serialimport timeimport datetime
# Try connecting to The XBee COM porttry: ser = serial.Serial(8,timeout=1) # open COM9 serial port print ser.portstr # check which port was really usedexcept: print "No Port Detected" ser = "0.0"
### Set global vers ###global cir_sel; cir_sel = "1"global i; i = 1global j; j = 1global k; k = 1global Kwh_tot; Kwh_tot = 0.0global cost_char; cost_char = "1"global time_last; time_last = time.time()global p1_tot; p1_tot = 0.0global p2_tot; p2_tot = 0.0global p3_tot; p3_tot = 0.0
### define the class ###class simpleapp_tk(Tkinter.Tk): def __init__(self,parent): Tkinter.Tk.__init__(self,parent) self.paremt = parent self.initialize()### Define Buttons ### def initialize(self): self.grid()
#initialize breaker select buttons #Star button resets KWh and total cost StartButton = Tkinter.Button(self, text=u"ReStart "
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, command=self.OnStartButtonClick) StartButton.grid(column = 0, row=0, rowspan = 2, sticky='NEWS', padx=1,pady=1) #button 1 3 are for current display button = Tkinter.Button(self, text=u"Breaker one " , command=self.OnButtonClick) button.grid(column = 0, row=2, sticky='W', padx=1,pady=1)
button2 = Tkinter.Button(self, text=u"Breaker two " , command=self.OnButtonClick2) button2.grid(column= 0, row=3, sticky='W', padx=1,pady=1)
button3 = Tkinter.Button(self, text=u"Breaker three" , command=self.OnButtonClick3) button3.grid(column= 0, row=4, sticky='W', padx=1,pady=1)
#button 4 6 are breaker disengage buttons self.buttonVariable = Tkinter.StringVar() self.buttonVariable.set("Disengage") button4 = Tkinter.Button(self, textvariable=self.buttonVariable, command =self.OnButtonClick4) button4.grid(column = 3, row=2, sticky='E') #sticky='E'
self.buttonVariable2 = Tkinter.StringVar() button5 = Tkinter.Button(self, textvariable=self.buttonVariable2,command=self.OnButtonClick5) button5.grid(column= 3, row=3, sticky='E') self.buttonVariable2.set(u"Disengage")
self.buttonVariable3 = Tkinter.StringVar() button6 = Tkinter.Button(self, textvariable=self.buttonVariable3,command=self.OnButtonClick6) button6.grid(column= 3, row=4, sticky='E') self.buttonVariable3.set(u"Disengage")
#Text entry field for setting price per KWh self.entryVariable = Tkinter.StringVar() self.entry = Tkinter.Entry(self, textvariable=self.entryVariable) self.entry.grid(column = 1, sticky='EW') self.entry.bind("<Return>", self.OnPressEnter) self.entryVariable.set(u"Enter Price Per kWh.") ############################################# # Label Declarations # # # #############################################
#labels for displaying circuit breaker power usage self.labelVariable1 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable1, anchor="w", fg="white", bg="blue") label.grid(column=1, row=2, columnspan=1,sticky='WE')
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self.labelVariable1.set(u" 0.0000W | 0.0000KWh | 0.0000$ ")
self.labelVariable2 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable2, anchor="w", fg="white", bg="blue") label.grid(column=1, row=3, columnspan=1,sticky='WE') self.labelVariable2.set(u" 0.0000W | 0.0000KWh | 0.0000$ ")
self.labelVariable3 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable3, anchor="w", fg="white", bg="blue") label.grid(column=1, row=4, columnspan=1,sticky='WE') self.labelVariable3.set(u" 0.0000W | 0.0000KWh | 0.0000$ ")
# Total power displays self.topBanner = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.topBanner, anchor="w", fg="blue", bg="white") label.grid(column=1, row=0, columnspan=3, sticky='EW') self.topBanner.set(u" Power | KWh | Cost ")
self.totalVals = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.totalVals, anchor="w", fg="blue", bg="white") label.grid(column=1, row=1, columnspan=3, sticky='EW') self.totalVals.set(u" 0.0000W | 0.0000KWh | 0.0000$ ")
#Bottom of the screen data labels self.labelVariable4 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable4, anchor="w", fg="white", bg="blue") label.grid(column=0, row=6, columnspan=4,sticky='EW') self.labelVariable4.set(u"Voltage: 0V")
self.labelVariable5 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable5, anchor="w", fg="white", bg="blue") label.grid(column=0, row=7, columnspan=4,sticky='EW') self.labelVariable5.set(u"current: 0A")
self.labelVariable6 = Tkinter.StringVar() label = Tkinter.Label(self, textvariable=self.labelVariable6, anchor="w", fg="white", bg="blue") label.grid(column=0, row=8, columnspan=4,sticky='EW') self.labelVariable6.set(u"Cost per KWh: 1.00$")
# resizing stuff self.grid_columnconfigure(0, weight=1) self.resizable(True,False)
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self.update() self.geometry(self.geometry()) self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
############################################# # button click Definitions # # # ############################################# def OnStartButtonClick(self): # Restart global Kwh_tot; Kwh_tot = 0.0 global p1_tot; p1_tot = 0.0 global p2_tot; p2_tot = 0.0 global p3_tot; p3_tot = 0.0 self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
def OnButtonClick(self): # Circuit one global cir_sel; cir_sel = "1" self.entry.focus_set() self.entry.selection_range(0, Tkinter.END) print "Circuit one outputting"
def OnButtonClick2(self): # Circuit two global cir_sel; cir_sel = "2" self.entry.focus_set() self.entry.selection_range(0, Tkinter.END) print "Circuit two outputting"
def OnButtonClick3(self): # Circuit three global cir_sel; cir_sel = "3" self.entry.focus_set() self.entry.selection_range(0, Tkinter.END) print "Circuit three outputting"
#### Relay buttons ### def OnButtonClick4(self): if i == 1: ser.write("a") self.buttonVariable.set("engage ") global i; i = 0 else: ser.write("A") self.buttonVariable.set("Disengage") global i; i = 1 self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
def OnButtonClick5(self): if j == 1:
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ser.write("b") self.buttonVariable2.set("engage ") global j; j = 0 else: ser.write("B") self.buttonVariable2.set("Disengage") global j; j = 1 self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
def OnButtonClick6(self): if k == 1: ser.write("c") self.buttonVariable3.set("engage ") global k; k = 0 else: ser.write("C") self.buttonVariable3.set("Disengage") global k; k = 1 self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
### Text field entry ### def OnPressEnter(self, event): global cost_char; cost_char = self.entryVariable.get() self.labelVariable6.set("Cost per KWh:" + self.entryVariable.get() + "$") self.entry.focus_set() self.entry.selection_range(0, Tkinter.END)
############################################## Background Loop ## ##############################################def task(): st = "w" global cir_sel; global time_last; ser.flushInput() # flush out any erroneous data ser.write(st) # send command to AtMega time.sleep(1) # wait a sec for data to come back current1 = ser.read(4) current2 = ser.read(4) current3 = ser.read(4) voltage = ser.read(4) try: # If valid data is not received skip main loop c1 = float(current1) #convert string to float vals c2 = float(current2) c3 = float(current3) v = float(voltage) time_now = time.time() #calculate time difference
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time_diff = float(time_now time_last) time_last = time_now print str(time_diff) app.labelVariable6.set(u"Price per KWh: " + cost_char + "$") p1 = c1*v #calculate instantaneous power power1 = str(p1) p2 = c2*v power2 = str(p2) p3 = c3*v power3 = str(p3) power_tot = p1 + p2 +p3 Kwh = power_tot*time_diff/3600000 #calculate Kilowatt hours P1_KWh = p1*time_diff/3600000 P2_KWh = p2*time_diff/3600000 P3_KWh = p3*time_diff/3600000 global Kwh_tot; Kwh_tot = Kwh_tot + Kwh global p1_tot; p1_tot = p1_tot + P1_KWh global p2_tot; p2_tot = p2_tot + P2_KWh global p3_tot; p3_tot = p3_tot + P3_KWh KWh_total = str(round(Kwh_tot,4)) global cost_char; global hold_cost_char; try: #throw an error is user inserts invalid Cost input junk = float(cost_char) except ValueError,e: print "error",e,"on line",i cost_char = hold_cost_char app.labelVariable6.set(u"type in value as X.XX format") cost_float = float(cost_char) hold_cost_char = cost_char tot_cost = Kwh_tot*cost_float total_cost = str(round(tot_cost,4)) #calculate total cost ### Print the labels ### app.totalVals.set(u" " + str(round(power_tot,2)).ljust(7,'0') + "W | " + KWh_total.ljust(6,'0')+"KWh | "+total_cost.ljust(6,'0') +"$ ") app.labelVariable4.set(u"Voltage: " + voltage + " Volts") if cir_sel == "1": cur_display = current1 elif cir_sel == "2": cur_display = current2 elif cir_sel == "3": cur_display = current3 app.labelVariable5.set(u"Current" + cir_sel + ": " + cur_display + "Amps") app.labelVariable1.set(u" " + str(round(p1,2)).ljust(7,'0') + "W | " +str(round(p1_tot,4)).ljust(6,'0') +"KWh | "+str(round(p1_tot*cost_float,4)).ljust(6,'0')+"$ ") app.labelVariable2.set(u" " + str(round(p2,2)).ljust(7,'0') + "W | " +str(round(p2_tot,4)).ljust(6,'0') +"KWh | "+str(round(p2_tot*cost_float,4)).ljust(6,'0')+"$ ") app.labelVariable3.set(u" " + str(round(p3,2)).ljust(7,'0') + "W | " +str(round(p3_tot,4)).ljust(6,'0') +"KWh | "+str(round(p3_tot*cost_float,4)).ljust(6,'0')+"$ ") except:
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print "missed a step" app.entry.focus_set() app.entry.selection_range(0, Tkinter.END) app.after(5000,task)
############################################## The end ## ##############################################if __name__ == "__main__": app = simpleapp_tk(None) app.title('BreakerBox GUI') app.after(5000,task) app.mainloop()
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Appendix BMicrocontroller program:/* * Created : 2/11/2013 * Author : Ambrose Coulliette * Last mod: 3/7/2013 * AtMill with PYSERAL V 2.0 */
#include <avr/io.h>#include <util/delay.h>#include <string.h>#define F_CPU 1000000L//#define BAUD 9600//#define MYUBRR F_CPU/16/BAUD1
///////// LCD functions /////void lcd_command(char);void lcd_char(char);void lcd_string(char *data);void lcd_init();
///////USART XBEE STUFF/////void USART_Init( unsigned int baud );void USART_Transmit( unsigned char );// data outunsigned char USART_Receive( void ); //returns UDRnunsigned char usart_kbhit(void);void USART_Flush( void );void usart_putchar(char data);void usart_putstring(char *data);void number_to_usart( float number_float);unsigned int baud = 6;
/////// ADC functions //////long int ADC_read( void );float ADC_scale( long int volt_float );void volt_to_LCD( float volt_float);
////// other initializations /////char temp, temp2;char test_char;int x;
/************************** MAIN PROGRAM ***********************/
int main(void)
ADCSRA = 0X80;
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ADMUX = 0x60;DIDR0 = 0x01;DDRB = 0xFF;DDRD = 0xFF;
_delay_ms(100);lcd_init();USART_Init( baud );PRR0 = (0 << PRUSART0);unsigned int highest_volt = 0;int sample = 217;float volt_float[217];float RMSvoltage ;float RMScurrent[3];float RMS = 0;float Power[3];float Power_tot;float Currection_factor[3] = 1.17,1.18,1.16;
lcd_string("Line:One |Two |Three");lcd_command(0xC0); //Send cursor to line 2lcd_string("Volt: | |");lcd_command(0x94); //Send cursor to line 3lcd_string("curr:");lcd_command(0xD4); //Send cursor to line 4lcd_string("Powe:");
while( 1) /// Main Loop ///
for(int k = 0; k < 4; k++)
if(k == 0 )ADMUX = 0x60;
else if(k == 1)
ADMUX = 0x61;else if(k == 2)
ADMUX = 0x62;else
ADMUX = 0x63;/****** Zero Crossing *****/if(k != 3)
int Z = 1;while(Z != 0)
Z = ADC_read();
24
elseint Z = 1024;while(Z > 20)
Z = ADC_read();
/****************************/
int Z = 1024;while(Z > 100)
Z = ADC_read();
for(int i = 0; i < sample ; i++)volt_float[i] = ADC_read();
RMS = 0;
for(int i = 0 ; i < sample; i++) volt_float[i] = ADC_scale(volt_float[i]); volt_float[i] = (volt_float[i]*volt_float[i]);
RMS = RMS + volt_float[i];
if( RMS < 0.010) RMS = 0;
RMS = sqrt(RMS/sample); _delay_ms(100); if(k < 3) RMScurrent[k] = ((RMS/664) * 2000)*1.163; else
RMSvoltage = RMS*49.2; Power[k] = RMScurrent[k] * RMSvoltage;
Power_tot = Power[0] + Power[1] + Power[2];
/*********** read from UART *********/if(usart_kbhit()) test_char = USART_Receive();
/********* print to USART *********/test_char = test_char & 0x7f;
if(test_char == 'w')
25
number_to_usart(RMScurrent[0]);number_to_usart(RMScurrent[1] );number_to_usart(RMScurrent[2] );number_to_usart(RMSvoltage );
else if(test_char == 'a')
PORTB |= (1<<PORTB0);
else if(test_char == 'A')
PORTB &= ~(1<<PORTB0);else if(test_char == 'b' )
PORTB |= (1<<PORTB1);else if(test_char == 'B' )
PORTB &= ~(1<<PORTB1);
else if(test_char == 'c' )PORTB |= (1<<PORTB2);
else if(test_char == 'C' )
PORTB &= ~(1<<PORTB2);
/*********** Write to LCD **********/
lcd_command(0xC5);volt_to_LCD(RMSvoltage);lcd_command(0x99);volt_to_LCD(RMScurrent[0]);lcd_string("|");volt_to_LCD(RMScurrent[1]);lcd_string("|");volt_to_LCD(RMScurrent[2]);lcd_command(0xD9);volt_to_LCD(Power[0]);lcd_string("|");volt_to_LCD(Power[1]);lcd_string("|");volt_to_LCD(Power[2]);
/////////////////////////////////////////////////// Functions begin //////////////////////////////////////////////////////////////********************* LCD functions ********************/void lcd_init()
26
DDRC = 0xCF; //Set port C for outputlcd_command(0x33); //Initialize LCD Driverlcd_command(0x32); //Four bit modelcd_command(0x2C); //4 Line Modelcd_command(0x0C); // Display On, Cursor Off, Blink Offlcd_command(0x01); //Clear Screen, Cursor Home
void lcd_command(char cmd)
char temp = cmd;PORTC=0;
_delay_ms(5);
cmd = ( (cmd & 0xF0) >> 4) | 0x80; //Write Upper Nibble (RS=0) E > 1PORTC = cmd;_delay_ms(5);cmd ^= 0x80; //E > 0PORTC = cmd;
_delay_ms(5);
cmd = temp;cmd = ( (cmd & 0x0F) ) | 0x80; //Write Lower Nibble (RS=0) E > 1PORTC = cmd;_delay_ms(5);cmd ^= 0x80; //E > 0PORTC = cmd;
_delay_ms(7);
void lcd_string(char *data) //stringwhile(*data)
lcd_char(*data);data++;
void lcd_char(char data)
char temp = data;PORTC = 0x40;
_delay_ms(5);
data = ( (data & 0xF0) >> 4) | 0xC0; //Write Upper Nibble (RS=1) E > 1
27
PORTC = data;_delay_ms(5);data ^= 0x80; // E > 0PORTC = data;
_delay_ms(5);data = temp;
data = ( (data & 0x0F) ) | 0xC0; //Write Lower Nibble (RS=1) E > 1PORTC = data;_delay_ms(5);data ^= 0x80; //E > 0PORTC = data;
_delay_ms(7);
/********************** USART functions ***************************/
void USART_Init( unsigned int baud ) UBRR0 = baud; /* Set baud rate */
/* Enable receiver and transmitter */UCSR0B = (1<<RXEN0)|(1<<TXEN0);/* Set frame format: 8data, 1stop bit */UCSR0C = (0<<USBS0)|(3<<UCSZ00)|(UPM00 << 0)|(UPM01 << 0);
unsigned char USART_Receive( void )
/* Wait for data to be received */while ( !(UCSR0A & (1<<RXC0)) );/* Get and return received data from buffer */return UDR0;
void USART_Flush( void )
unsigned char dummy;while ( UCSR0A & (1<<RXC0) ) dummy = UDR0;
void usart_putchar(char data) // Wait for empty transmit bufferwhile ( !(UCSR0A & (_BV(UDRE0))) );// Start transmissionUDR0 = data;
void usart_putstring(char *data) //string
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while(*data)usart_putchar(*data);*data ++;
unsigned char usart_kbhit(void) //return nonzero if char waiting polled versionunsigned char b;b=0;if(UCSR0A & (1<<RXC0)) b=1;return b;
void number_to_usart( float number_float)char number_char;int i = 0;
while(number_float > 10.0)number_float = number_float/10.0;i++;
number_char = number_float + 0x30; //48usart_putchar(number_char);if( i == 0)
usart_putchar('.');
number_char =number_float*10;while(number_char >= 10.0)number_char = number_char 10.0;number_char = number_char + 0x30;usart_putchar(number_char);
if( i == 1)usart_putchar('.');
number_char =number_float*100;while(number_char >= 10.0)number_char = number_char 10.0;number_char = number_char + 0x30;usart_putchar(number_char);
if( i == 2)usart_putchar('.');
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/************* ADC functions ***********/long int ADC_read( void )ADCSRA = 0xC0; //singular shot
while( bit_is_set(ADCSRA,6 ) != 0) //wait for flag loop int ADCLOW = ADCL;long int volt = ADCH;
volt = volt << 2; ADCLOW = ADCLOW >> 6; volt = volt + ADCLOW;
return volt;
float ADC_scale( long int volt )float volt_in = volt / 204.6; //returns float val from 0V to 5Vreturn volt_in;
void volt_to_LCD( float volt_float)char volt_char;int i = 0;
while(volt_float > 10.0)volt_float = volt_float/10.0;i++;
volt_char = volt_float + 0x30;lcd_char(volt_char);if( i == 0)
lcd_char('.');
volt_char =volt_float*10;while(volt_char >= 10.0)volt_char = volt_char 10.0;volt_char = volt_char + 0x30;lcd_char(volt_char);
if( i == 1)lcd_char('.');
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volt_char =volt_float*100;while(volt_char >= 10.0)volt_char = volt_char 10.0;volt_char = volt_char + 0x30;lcd_char(volt_char);
if( i == 2)lcd_char('.');
if( i == 3)
volt_char =volt_float*1000;while(volt_char >= 10.0)
volt_char = volt_char 10.0;volt_char = volt_char + 0x30;lcd_char(volt_char);
Appendix CProject video link:http://youtu.be/8o95yYlJLIU
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