5. 5
ABSTRACT
The object of this project was to build a single compact system that could properly read various climate
conditions and then alert the host via text messaging of those conditions. The idea was sparked by the
coming of spring and the inconsistency of the weather. Our small boxed station provided the user quick
reminders of the current conditions outside without watching the news or even opening your phone.
BeagleBone Black and Cloud9 software was use to program one BeagleBone Black single board
computer. Two I2C sensors were used to take readings. One of the two was the SI1145 UV sensor, the
other was the BMP180 temperature and barometric pressure sensor. On the front panel is a single serial
LCD screen, four LEDs one of which is RGB, a toggle switch for mode selection and two pushbuttons for
manual manipulation. The LEDs are color coded for UV indications and the Serial LCD screen gives
prompts and shows visible readings.
The end game of the project is to model a portable, easy to set up, weather station that can notify anyone
what the outside conditions are at any given moment. The system can help prioritize ones activities and
time with precise readings and clear notifications.
6. 6
INTRODUCTION
The weather is constantly fluctuating throughout the day. At one time it can be sunny with no clouds in
sight then 30 minutes later it can be raining. On other days the UV rays can be really high and other it will
not be. These fluctuations on climates conditions can cause some people hassle and other to be ill
prepared to go outside.
This is why we engineered the weather station. This station helps utilize time management by pre-
prompting the user with valuable outside information catering to their condition. Some of these conditions
include but are not limited to temperature, humidity, barometric pressure and UV index. One does not
have to turn on the TV and wait for the news to inform them that it’s raining outside. One also does not
have to get a weather app or widget on their phone since the weather information will already be sent to
them.
Engineering is a way to simplify the future and help the mass public prioritize every measure of their life.
This small system helps that future prioritize.
7. 7
OPERATING INSTRUCTIONS
User Interface:
4-Leds UV index:
1) UV index 0-2 (indicates safe UV reading, Green LED)
2) UV index 3-5 (indicates average UV reading, Yellow LED)
3) UV index 6-7 (indicates high UV reading, Orange LED)
4) UV index 8-10 (indicates very high UV reading, Red LED)
5) UV index 11+ (RGB LED shared with green, indicates dangerous levels of UV, Blue LED)
Figure 1.User Interface
1-Toggle Switch:
Mode select (up-manual, down-automatic)
2-Push-buttons (manual mode only):
Black (Scroll button, scrolls available reading options)
Red (Select button, Takes the reading indicated by the scroll push button)
1-Serial LCD screen:
Displays information to user of which reading is currently displayed which mode you are in and
team name and information.
8. 8
Operating Instructions:
1) Plug a 5v barrel jack into the system.
Figure 2. HNR Weather Station Ports
Upon being powered on the project name and the initials of the group member will be displayed.
Figure 3. Startup Display
After the startup, the system will be in auto mode.
In auto mode, the screen will cycle through the readings and light the corresponding LED.
2) At this point you can set the desired mode by flipping the toggle switch.(up-manual or down-
auto)
This can be set at any time after the startup. The device can transition from one mode to another
at any time during the device operation.
3) If auto is set (toggle-down), the system cycles through the reading as shown below.
9. 9
Figure 4. Auto Mode-Current Temp
Figure 5. Auto Mode-Baro. Pressure
10. 10
Figure 6. Auto Mode-UV Index
4) If manual mode is set (toggle-up), the system operates by pressing the pushbuttons.
By pressing the scroll, button the screen cycles through the readings.
After which by pressing the select button you have selected that reading for display.
Figure 7. Manual Mode
13. 13
Hardware Description
Figure 12. BeagleBone Black
The central controller is the BeagleBone Black. The capabilities of this single board computer include but
not limited to: 2 ports with 46 I/O pins, UART, SPI, I2C, 1GHz processor, and the Linux operating
system.
This single board controls all of the switches, LEDs, communication with the two I2
C sensors,
communication with the serial LCD , call functions, and everything else that has to do with the project.
Through a series of serial and I2C commands the computer gets the sensor data and displays it on the
screen.
LEDs:
Figure 13. LEDs
The 4 LEDs provide real-time indication of the current UV index value. The first LED is a RGB LED that
shows both green and blue when indicated. The LEDs are setup to respond to an active high from the
BBB. The other three LEDs are red, yellow, and orange. These LEDs correspond to the UV index levels.
These LEDs are also connected to pins 7, 8, 9, 10, and 11 on the P8 header of the BBB.
14. 14
Switches:
Figure 14. Mode Selection Switch
There is one SPST toggle switches that controls the mode selection. One side of the switch is tied to
ground and the other is tied to a controller pin and the BBB’s internal pull-up resistor. This switch is
connected to the P8 header pin 14 on the board.
Pushbuttons:
Figure 15. Scroll & Select Buttons
Two pushbuttons are implemented in the design. The pushbuttons are normally open circuits. On one side
of the pushbuttons is ground. The other side connects to P8 pin 12 and 13 on the board as well as a pull-
up resistor to 3.3v.
Serial LCD:
Figure 16. Sparkfun Serial LCD
A 3.3v 16x2 serial LCD display is used in the design. The LCD has 3 wires power, ground and receive.
The receive wire connects to the controller using P9 pins 13. The other two wires are connected to 3.3v
and ground on the board P9 pin 3 and P9 pin 1 respectively.
15. 15
SI1145 UV sensor:
Figure 17. SI1145 UV Index Sensor
The SI1145 is a UV sensor that runs off 3.3v and is I2
C compatible. The board has the standard data line,
clock line, power and ground. The board uses P9 pin 19 for SCL and P9 pin 20 for SDA. The power and
ground are connected to the on board 3.3v supply and ground. This sensor gives off the UV reading as a
16bit Hex number that has to be converted in to the proper UV index reading.
BMP180 Temp. Pressure sensor:
Figure 18. BMP180 Temp. & Baro. Pressure Sensor
The BMP180 is a temperature and pressure sensor. It runs off 3.3v and is I2
C compatible. The board has
the standard data line, clock line, power and ground. The board uses P9 pin 19 for SCL and P9 pin 20 for
SDA. The power and ground are connected to the on board 3.3v supply and ground. The sensor returns
the readings as character strings.
16. 16
Software Description:
The BBB computer sends data to the SI1145 and BMP180 respectively to initialize both sensors and take
a reading. To do this a series of system commands are sent through I2C connection to each board. In case
of the SI1145 one must first write 0x17 HEX to address 0x07 via the i2cset command. After a few other
set commands, when ready by writing 0x07 HEX to address 0x18, 0x12 HEX to address 0x18 and
reading registers 0x2C and 0x2D respectively you have just forced a measurement and read the return
value After this is done the read output is redirected into a file on the BBB for manipulating. See Figure
18 for a code example.
Figure 19. SI1145 Configuration
To use the BMP180, I2
C must be enabled first on the BBB. This is done by using the echo command and
directing the output to /sys/device/bone_capemgr.9/slots. The output path is referred to as SLOTS in
Figure 19. Next the device drives must be load by using the command echo "bmp085 0x77" >
/sys/class/i2c-adapter/i2c-1/new_device. Next, the dmesg | grep bmp command is used to read the
kernel message to verify the device drivers were loaded properly
Figure 20. BMP180 Configuration
17. 17
To use the BMP180 sensor the device file paths is defined in the BMP180Temp-Pressure.c file. These
defined paths are then used to directly communicate with the board through file handling. The fopen
command is used to open the device file and the data is read into a character string buffer. These
characters have to be converted into floats in order to properly be displayed on the LCD. The atof
function is used to convert the character string to a float value. Figure 20 shows the exact code snippet
that does what was mentioned above.
Figure 21. BMP180 Operation Code
18. 18
Conclusion
Key Results and Findings
Designing an impromptu project on the fly with limited time and actually finish most of it was
great to see firsthand. By working in a group and dividing up the workload this was possible.
Unlike in digital we were able to skip some steps to speed up the process and used a better
controller and a higher level coding language. This helped the project run more smoothly but did
not extinguish all problems. We as a group had to be okay with making decisions that directly
affected our project and cope with major setbacks. This process helped developed skills that will
be essential as engineers. Skills from critical thinking to research and development were tested
and honed for future use in industry. The overall project experience was a step up from our last
one due to the upgrade in information and equipment. Therefore, this resulted in the process
running smoother.
Difficulties
Working with the BeagleBone Black single board computer was the focus of the project, but
surprisingly this was not the biggest issue we had. The I2
C set up gave us the biggest hassle due
to the lack of information on I2
C configuration. This caused us to use up valuable time in
understanding how our board uses its I2
C ports and how to communicate with our sensors within
c programing. We also spent multiple days reading the sensor data sheets trying to understand
how they communicate through I2
C. These tasks took away valuable time that could have been
used to refine and enhance the project. We had to remove one of the sensors as well as the Wi-Fi
dongle for text messaging. However, this simplified the project and taught us how to deal with
setbacks.
Next steps
Our original goal was to build a user friendly that would prepare the user for outside activates via
text messaging and/or email of the following conditions:
Temperature
Humidity
Barometric Pressure
UV index
Once this is accomplished we wanted to implement some type of internet connection that would
pull in more weather data and send that data to the user. Since these features were not
implemented in the current system, they are in the plans for future revisions. A better enclosure
that is durable for outside conditions should be used as well as some better wire connectors.
Lastly, some more LEDs for UV index should be included on the front panel to better display the
index.
19. 19
APPENDIX 1 – Parts List
Hardware
Part name Part number Quantity Price Total Vendor Surplus
BeagleBoneBlack (P/N:83-16241) 1 $39.99 $39.99 Microcenter Surplus
SI1145 (P/N: 1777) 1 $9.95 $9.95 Adafruit ----------
BMP180 (P/N: 1603) 1 $9.95 $9.95 Adafruit Surplus
3.3 V Serial LCD (P/N: LCD-09066) 1 $24.95 $24.95 SparkFun Surplus
LED Holders (Catalog #: 2760080) 2 $1.99 $3.98 Radioshack Surplus
SPST Momentary
Switch
(Catalog #: 2751547) 1 $3.99 $3.99 Radioshack Surplus
Toggle Switch (Catalog #: 55050562) 1 $3.20 $3.20 Radioshack Surplus
RGB LED (P/N:NTE30115) 1 $4.99 $4.99 Microcenter Surplus
LEDS N/A 3 N/A N/A SPSU Tech. Shop ----------
M to F Jumper
Cable Wires
(P/N: GK1212750) 1 $2.51 $2.51 Amazon Surplus
Resistors 1kΩ N/A 5 N/A N/A SPSU Tech. Shop -----------
-
Breadboard (P/N: 090302_F) 1 $5.95 $5.95 Amazon Surplus
TOTAL $109.46
23. 23
APPENDIX 4 – Source Code
WeatherStationMain.c
/******************************************************************************
* Name : WeatherStationMain.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* This code handles the running of the system while in manual
* mode.
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include "WeatherStation.h"
int main()
{ int modeSwitchState;
int trueLock =1;
int increment = 0;
char tempBuffer[7];
char pressureBuffer[11];
char startScreen1 [] = " HNR ";
char startScreen2 [] = " Weather Station";
char tempString [] = " Current Temp: ";
char tempPrintPosition [] = "xC5";
char baroString [] = " Baro. Pressure:";
char baroPrintPosition [] = "xC3";
char manualModeString [] = " Manual Mode ";
char UVString [] = " UV Index: ";
char UVindex[6];
char UVPrintPosition [] = "xC6";
float UVvalue;
clearScreen();
writeToScreen(startScreen1);
writeToScreen(startScreen2);
sleep(2);
clearScreen();
initSi1145();
//---------------------------------------------------------------------------
// infinite loop
// Continually gets the current temperature and barometric pressure and
// writes it to the LCD screen. In addition, it continually gets the
// UV index value and displays it on the screen and turns on the
// corresponding LED. Also, this loop continually checks to see if the
// Manual Mode Switch has been activated.
//---------------------------------------------------------------------------
while (trueLock ==1)
{
clearScreen();
writeToScreen(tempString);
24. 24
strcpy(tempBuffer, getTemp()); //copies the return value of getTemp into
//tempBuffer
moveCursor(tempPrintPosition);
writeToScreen(tempBuffer);
ManualModeCheck();
clearScreen();
writeToScreen(baroString);
strcpy(pressureBuffer, getPressure()); //copies the return value of
//getPressure into pressureBuffer
moveCursor(baroPrintPosition);
writeToScreen(pressureBuffer);
ManualModeCheck();
clearScreen();
resetLEDS();
UVvalue = readUV();
sprintf(UVindex, "%.3f",UVvalue); //float to string conversion
writeToScreen(UVString);
moveCursor(UVPrintPosition);
writeToScreen(UVindex);
turnOnUVIndexLEDs(UVvalue);
ManualModeCheck();
}
return EXIT_SUCCESS;
}
UVLEDs.c
/******************************************************************************
* Name : UVLEDs.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* Compares the inputted UV index value to determine which LED to
* turn on.
*****************************************************************************/
#include <stdio.h>
#include "WeatherStation.h"
/*==============================================================================
* Function : turnOnUVIndexLEDs
* Return : none
* Parameters : float UVvalue: UV index value
* Description :
* Compares the inputted UV index value to determine which LED to
* turn on.
*
* Green Yellow Orange Red Blue
* 1 2 3 4 5 6 7 8 9 10 11
*==============================================================================
*/
25. 25
void turnOnUVIndexLEDs(float UVvalue)
{
if (UVvalue <=2.00)
{
printf ("Green LED ON!n");
setLed('g', LED_ON);
}
if (UVvalue >2.00 && UVvalue <= 5.00)
{
printf ("Yellow LED ON!n");
setLed('y', LED_ON);
}
if (UVvalue >5.00 && UVvalue <= 7.00)
{
printf ("Orange LED ON!n");
setLed('o', LED_ON);
}
if (UVvalue >7.00 && UVvalue <= 10.00)
{
printf ("Red LED ON!n");
setLed('r', LED_ON);
}
if (UVvalue >10.00)
{
printf ("Blue LED ON!n");
setLed('b', LED_ON);
}
}
SI1145Handle.c
/******************************************************************************
* Name : SI1145Handle.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* Controls all the guts of the programming. The text output of the
* readings are redirected into the "UV.txt" file. That file is then
* read into a buffer which is compared to known HEX values for
* decimal conversion:
*
* 'Handle' = Compares UV.txt to known HEX values.
* 'Convert' = Makes decimal equivalent of HEX values.
*
*****************************************************************************/
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <unistd.h>
26. 26
#include "WeatherStation.h"
//--Global variables for loops and usleep constants---------------------------
int a;
int b;
int c;
int d;
/*==============================================================================
* Function : Handle
* Return : none
* Parameters : none
* Description :
* Compares UV.txt to HEX char array and index holds value.
* Calls Convert when all HEX compares are done.
*==============================================================================
*/
void Handle(void)
{
//--Clears all variables before compares are done-------------------------
a = 0;
b = 0;
c = 0;
d = 0;
//--established standard array/w pointer---------------------------------
char UVband[17]={'0','1','2','3','4','5','6','7','8','9',
'a','b','c','d','e','f'};
//--Initialization of buffer array---------------------------------------
char UVbuffer[9];
FILE *fileHandle = NULL;
//--Read UV.txt Hex values------------------------------------------------
if ((fileHandle = fopen("UV.txt", "r")) != NULL)
{
fread(UVbuffer, sizeof(char), 9, fileHandle);
fclose(fileHandle);
}
//--Print what's in the UV.txt file to the front screen------------------
do
{
printf("n %c", UVbuffer[a]);
a ++;
}
while(a < 9);
//--Clears the a variable to be reused for the compare-------------------
a = a*0;
//------------------------------------------------------------------------
// do while loop
27. 27
// Comparing the frist Hex value in UV.txt to '0' in the char array.
//------------------------------------------------------------------------
do
{
//--Compares if valus is equal----------------------------------------
if (UVbuffer[2] == UVband[a])
{
//--if compare true sleep for a second--------------------------------
sleep(1);
}
//--Handles prompt if nothing was matched-----------------------------
else
{
//--moves to the next index in char array------------------------
++ a;
}
}
//--Continues the do/while until a match is found------------------------
while(UVbuffer[2] != UVband[a]);
//-----------------------------------------------------------------------
// do while loop
// Comparing the second Hex value in UV.txt to '0' in the char array.
//------------------------------------------------------------------------
do
{
//--Compares if valus is equal----------------------------------------
if (UVbuffer[3] == UVband[b])
{
//--if compare true sleep for a second--------------------------------
sleep(1);
}
//--Handles prompt if nothing was matched------------------------------
else
{
//--moves to the next index in char array-------------------------
++ b;
}
}
//--Continues the do/while until a match is found------------------------
while(UVbuffer[3] != UVband[b]);
//------------------------------------------------------------------------
// do while loop
// Comparing the third Hex value in UV.txt to '0' in the char array.
//------------------------------------------------------------------------
do
{
//--Compares if valus is equal----------------------------------------
if (UVbuffer[7] == UVband[c])
{
//--if compare true sleep for a second--------------------------------
sleep(1);
}
//--Handles prompt if nothing was matched-------------------------------
else
28. 28
{
//--moves to the next index in char array------------------------
++ c;
}
}
//--Continues the do/while until a match is found------------------------
while(UVbuffer[7] != UVband[c]);
//------------------------------------------------------------------------
// do while loop
// Comparing the fourth Hex value in UV.txt to '0' in the char array.
//------------------------------------------------------------------------
do
{
//--Compares if valus is equal----------------------------------------
if (UVbuffer[8] == UVband[d])
{
//--if compare true sleep for a second--------------------------------
sleep(1);
}
//--Handles prompt if nothing was matched-------------------------------
else
{
//--moves to the next index in char array------------------------
++ d;
}
}
//--Continues the do/while until a match is found------------------------
while(UVbuffer[8] != UVband[d]);
}
/*==============================================================================
* Function : Convert
* Return : none
* Parameters : none
* Description :
* Called from Handle takes the global variables and adds them
* together to get the decimal equivalent of those HEX values. Then
* does the UV conversion turning the decimal into a float that
* holds the UV index number.
*==============================================================================
*/
float Convert()
{
printf("n you are in convert");
//--Local variables to hold float UV index-------------------------------
float e = 0;
//--Multiplying the Global variables by there decimal equivalent---------
a = a*256;
b = b*16;
//--Turns the decimal number into a float--------------------------------
e = (a + b + c)/1000.00;
//--Prints float to the front screen-------------------------------------
printf("n %f", e);
return e;
29. 29
}
SI1145main.c
/******************************************************************************
* Name : SI1145main.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* Controls all system commands and I2C setup for communicating to
* the UV sensor. This code is also responsible for redirecting the
* UV reading output into the UV.txt file for future comparison:
*
* 'main' = Sets all parameters for the I2C communication between
* the UV board and the BBB.
* 'reset' = Resets all registers and parameters in the UV board.
* 'readUV' = Calls Handle and Convert for processing of the UV
* reading.
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <unistd.h>
#include "WeatherStation.h"
/*==============================================================================
* Function : main
* Return : none
* Parameters : none
* Description :
* Sets up all I2C commands, UV board registers and parameters for
* communication.
*==============================================================================
*/
void initSi1145()
{
//--I2C command to Initialize UV board--------------------------------------
system("i2cset -y 1 0x60 0x07 0x17");
usleep(100);
//--I2C commands for setting proper coefficents for UV reading--------------
system("i2cset -y 1 0x60 0x13 0x29");
system("i2cset -y 1 0x60 0x14 0x89");
system("i2cset -y 1 0x60 0x15 0x02");
system("i2cset -y 1 0x60 0x16 0x00");
//--I2C command for setting enabling the UV reader-------------------------
system("i2cset -y 1 0x60 0x17 0xf0");
system("i2cset -y 1 0x60 0x18 0xa1");
//--I2C command for UV enable confirmation---------------------------------
system("i2cget -y 1 0x60 0x2e");
//--Calls for a UV reading and reset when doone----------------------------
}
30. 30
/*==============================================================================
* Function : reset
* Return : none
* Parameters : none
* Description :
* Resets all prior set parameters and registers in case of error.
*==============================================================================
*/
void reset(void)
{
//--I2C comand for resetting all set registers and parameters---------------
system("i2cset -y 1 0x60 0x18 0x01");
}
/*==============================================================================
* Function : readUV
* Return : none
* Parameters : none
* Description :
* Makes conversion in UV board pulls it out and populates UV.txt.
* Also calls proper functions for hadling the UV.txt compares.
*==============================================================================
*/
float readUV(void)
{
//--I2C command for taking a forced reading and redirecting the output------
system("i2cset -y 1 0x60 0x18 0x07");
system("i2cset -y 1 0x60 0x18 0x12");
system("i2cget -y 1 0x60 0x2D > UV.txt");
system("i2cget -y 1 0x60 0x2C >> UV.txt");
//--Calls Handle and Convert for file manipulation-------------------------
float indexValue;
Handle();
indexValue=Convert();
return indexValue;
}
SerialLCD.c
/******************************************************************************
* Name : SerialLCD.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* This file contains the functions necessary to use the
* SparkFun 3.3V Serial Enabled 16x2 LCD.
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "WeatherStation.h"
31. 31
#define LCD_UART4_FILE "/dev/ttyO4"
/*==============================================================================
* Function : writeToScreen
* Return : none
* Parameters : String of chars
* Description :
* Writes the input string to the LCD screen.
*==============================================================================
*/
void writeToScreen(char * buffer)
{
FILE * filePtr;
filePtr = fopen (LCD_UART4_FILE ,"r+"); //r+:Open a file for reading&write
fputs (buffer,filePtr);
fclose (filePtr);
}
/*==============================================================================
* Function : clearScreen
* Return : none
* Parameters : none
* Description :
* Sends the clear command (xFE followed by x01) to the LCD.
*==============================================================================
*/
void clearScreen()
{
char clearScreen[] = "xFEx01";
FILE * filePtr;
filePtr = fopen (LCD_UART4_FILE ,"r+"); //r+:Open a file for reading&write
fputs (clearScreen,filePtr);
fclose (filePtr);
}
/*==============================================================================
* Function : moveCursor
* Return : none
* Parameters : String of chars: The cursor position in hex to move to.
* Description :
* Concatenates "xFE with the input char string. This will give
* the LCD the command to move the cursor and the position to
* move the cursor to.
*==============================================================================
*/
void moveCursor(char * position)
{
char moveCursor[7] = "xFE";
strcat(moveCursor, position); //concatenates:(dest,src)
FILE * filePtr;
filePtr = fopen (LCD_UART4_FILE ,"r+"); //r+:Open a file for reading&write
fputs (moveCursor,filePtr);
fclose (filePtr);
}
32. 32
ManualMode.c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include "WeatherStation.h"
/******************************************************************************
* Name : ManualMode.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* This code handles the running of the system while in manual
* mode.
*****************************************************************************/
int modeSwitchState;
int increment = 0;
char manualModeString [] = " Manual Mode ";
char tempString [] = " Current Temp: ";
char tempBuffer[7];
char tempPrintPosition [] = "xC5";
char baroString [] = " Baro. Pressure:";
char baroPrintPosition [] = "xC3";
char pressureBuffer[11];
/*==============================================================================
* Function : ManualModeCheck
* Return : none
* Parameters : none
* Description :
* Checks if the Manual Modee Switch has been activated. If the
* Manual Mode Switch has been activated it checks whether the
* scroll switch has been pressed. If the Scroll Button has been
* pressed it checks what the current increment is and whether the
* Select Button has been pressed. The increment is used to
* determine what to write to the screen. If the Select Button is
* pressed and the increment is at one, the program will write the
* current temperature value to the screen. If the increment is at
* two, the program will write the current barometric pressure to
* the screen.
*==============================================================================
*/
void ManualModeCheck()
{
//--Creates 2 sec delay and checks switch state---------------------------------
for (int index = 0; index <200; index++)
{
modeSwitchState=isModeSwitchActive();
if (modeSwitchState==1) // if active
{
clearScreen();
writeToScreen(manualModeString);
sleep(2);
clearScreen();
33. 33
while (isModeSwitchActive() ==1)
{
if (isScrollButtonActive() ==1)
{ increment ++;
if (increment==1)
{
clearScreen();
writeToScreen(" Temperature ");
while (increment ==1)
{
//--checks state of the Select Button, Scrolll Button, and the Mode Switch------
if (isSelectButtonActive()==1)
{
clearScreen();
writeToScreen(tempString);
strcpy(tempBuffer, getTemp());
moveCursor(tempPrintPosition);
writeToScreen(tempBuffer);
break;
}
if (isScrollButtonActive() ==1)
{
increment ++;
break;
}
if (isModeSwitchActive() == 0) //Not active
{
break;
}
}
}
if (increment==2)
{
clearScreen();
writeToScreen(" Pressure ");
while (increment ==2)
{
//--checks state of the Select Button, Scrolll Button, and the Mode Switch------
if (isSelectButtonActive()==1)
{
clearScreen();
writeToScreen(baroString);
strcpy(pressureBuffer, getPressure());
moveCursor(baroPrintPosition);
writeToScreen(pressureBuffer);
break;
}
if (isScrollButtonActive() ==1)
{
increment ++;
break;
}
34. 34
if (isModeSwitchActive() == 0) //Not active
{
break;
}
}
}
if (increment ==3)
{
increment =0;
}
}
}
increment =0;
break;
}
//--10 ms delay-----------------------------------------------------------------
usleep(10000);
}
}
LED_Switches.c
/******************************************************************************
* Name : LED_Switches.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* This file contains the functions to initailize the LEDs and
* switches. In addition, this file contains the functions to check
* the state of the switches and reset the LEDs to off.
*
*****************************************************************************/
#include <stdio.h>
#include "WeatherStation.h"
#define MODE_SWITCH_DIRECTION_FILE "/sys/class/gpio/gpio26/direction"
#define MODE_SWITCH_VALUE_FILE "/sys/class/gpio/gpio26/value"
#define SCROLL_BUTTON_DIRECTION_FILE "/sys/class/gpio/gpio44/direction"
#define SCROLL_BUTTON_VALUE_FILE "/sys/class/gpio/gpio44/value"
#define SELECT_BUTTON_DIRECTION_FILE "/sys/class/gpio/gpio23/direction"
#define SELECT_BUTTON_VALUE_FILE "/sys/class/gpio/gpio23/value"
#define RED_LED_DIRECTION_FILE "/sys/class/gpio/gpio68/direction"
#define GREEN_LED_DIRECTION_FILE "/sys/class/gpio/gpio66/direction"
#define BLUE_LED_DIRECTION_FILE "/sys/class/gpio/gpio45/direction"
#define YELLOW_LED_DIRECTION_FILE "/sys/class/gpio/gpio67/direction"
#define ORANGE_LED_DIRECTION_FILE "/sys/class/gpio/gpio69/direction"
/*==============================================================================
* Function : initSwitchLed
35. 35
* Return : none
* Parameters : none
* Description :
* Initialize switch hardware and set default led state.
*==============================================================================
*/
void initSwitchLed(void)
{
//--place files paths within arrays to enable indexing through LEDs-------
const char *ledFiles[] = {RED_LED_DIRECTION_FILE,
GREEN_LED_DIRECTION_FILE,
BLUE_LED_DIRECTION_FILE,
YELLOW_LED_DIRECTION_FILE,
ORANGE_LED_DIRECTION_FILE};
FILE *fileHandle = NULL;
int i;
//--set initial LED state to off and port direction as output-------------
for (i=0; i<5; i++)
{
if ((fileHandle = fopen(ledFiles[i], "r+")) != NULL)
{
fwrite("low", sizeof(char), 3, fileHandle);
fclose(fileHandle);
}
}
//--set switch port direction----------------------------------------------
if ((fileHandle = fopen(MODE_SWITCH_DIRECTION_FILE, "r+")) != NULL)
{
fwrite("in", sizeof(char), 2, fileHandle);
fclose(fileHandle);
}
//--set button port direction----------------------------------------------
if ((fileHandle = fopen(SCROLL_BUTTON_DIRECTION_FILE, "r+")) != NULL)
{
fwrite("in", sizeof(char), 2, fileHandle);
fclose(fileHandle);
}
//--set button port direction----------------------------------------------
if ((fileHandle = fopen(SELECT_BUTTON_DIRECTION_FILE, "r+")) != NULL)
{
fwrite("in", sizeof(char), 2, fileHandle);
fclose(fileHandle);
}
}
/*==============================================================================
* Function : resetLEDs
* Return : none
* Parameters : none
* Description :
* Turns off all of the LEDs.
*==============================================================================
*/
36. 36
void resetLEDS()
{
//--place files paths within arrays to enable indexing through LEDs-------
const char *ledFiles[] = {RED_LED_DIRECTION_FILE,
GREEN_LED_DIRECTION_FILE,
BLUE_LED_DIRECTION_FILE,
YELLOW_LED_DIRECTION_FILE,
ORANGE_LED_DIRECTION_FILE};
FILE *fileHandle = NULL;
int i;
//--set initial LED state to off and port direction as output-------------
for (i=0; i<5; i++)
{
if ((fileHandle = fopen(ledFiles[i], "r+")) != NULL)
{
fwrite("low", sizeof(char), 3, fileHandle);
fclose(fileHandle);
}
}
}
/*==============================================================================
* Function : setLed
* Return : none
* Parameters : led = {Color}
* theState = {SWITCHLED_ON, SWITCHLED_OFF}
* Description :
* Change state of LED.
*==============================================================================
*/
void setLed(char led, int theState)
{
char *ledFile;
FILE *fileHandle = NULL;
switch(led)
{
case 'r':
ledFile = RED_LED_DIRECTION_FILE;
break;
case 'g':
ledFile = GREEN_LED_DIRECTION_FILE;
break;
case 'b':
ledFile = BLUE_LED_DIRECTION_FILE;
break;
case 'y':
ledFile = YELLOW_LED_DIRECTION_FILE;
break;
case 'o':
ledFile = ORANGE_LED_DIRECTION_FILE;
break;
}
if (theState == LED_ON)
{
//--turn LED on-------------------------------------------------------
37. 37
if ((fileHandle = fopen(ledFile, "r+")) != NULL)
{
fwrite("high", sizeof(char), 4, fileHandle);
fclose(fileHandle);
}
}
else
{
//--turn LED off------------------------------------------------------
if ((fileHandle = fopen(ledFile, "r+")) != NULL)
{
fwrite("low", sizeof(char), 3, fileHandle);
fclose(fileHandle);
}
}
}
/*==============================================================================
* Function : isModeSwitchActive
* Return : int {0 if not active, 1 if active}
* Parameters : none
* Description :
* Test switch state then return.
*==============================================================================
*/
int isModeSwitchActive(void)
{
FILE *fileHandle = NULL;
char buffer[2];
//--Read switch value-----------------------------------------------------
if ((fileHandle = fopen(MODE_SWITCH_VALUE_FILE, "r+")) != NULL)
{
fread(buffer, sizeof(char), 1, fileHandle);
fclose(fileHandle);
}
//--return appropriate value based upon switch position-------------------
if (buffer[0]=='0')
{
return 1; // Button is active.
}
else
{
return 0; // Button is not active.
}
}
/*==============================================================================
* Function : isScrollButtonActive
* Return : int {0 if not active, 1 if active}
* Parameters : none
* Description :
* Test switch state then return.
*==============================================================================
*/
int isScrollButtonActive(void)
{
38. 38
FILE *fileHandle = NULL;
char buffer[2];
//--Read switch value-----------------------------------------------------
if ((fileHandle = fopen(SCROLL_BUTTON_VALUE_FILE, "r+")) != NULL)
{
fread(buffer, sizeof(char), 1, fileHandle);
fclose(fileHandle);
}
//--return appropriate value based upon switch position-------------------
if (buffer[0]=='0')
{
return 1; // Button is active.
}
else
{
return 0; // Button is not active.
}
}
/*==============================================================================
* Function : isSelectButtonActive
* Return : int {0 if not active, 1 if active}
* Parameters : none
* Description :
* Test switch to state then return.
*==============================================================================
*/
int isSelectButtonActive(void)
{
FILE *fileHandle = NULL;
char buffer[2];
//--Read switch value-----------------------------------------------------
if ((fileHandle = fopen(SELECT_BUTTON_VALUE_FILE, "r+")) != NULL)
{
fread(buffer, sizeof(char), 1, fileHandle);
fclose(fileHandle);
}
//--return appropriate value based upon switch position-------------------
if (buffer[0]=='0')
{
return 1; // Button is active.
}
else
{
return 0; // Button is not active.
}
}
39. 39
BMP180Temp-Pressure.c
/******************************************************************************
* Name : BMP180Temp-Pressure.c
* Author : Harshpreet Saini, Norman Sims, Rahu M. Bannister
* Version : 1.0
* Copyright : 2015
* Description :
* This file contains the functions necessary to use the
* bmp180 temperature/barometric Pressure sensor.
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "WeatherStation.h"
#define TEMPERATURE_FILE "/sys/bus/i2c/drivers/bmp085/1-0077/temp0_input"
#define PRESSURE_FILE "/sys/bus/i2c/drivers/bmp085/1-0077/pressure0_input"
/*==============================================================================
* Function : getTemp
* Return : temperatureF: static char array
* Parameters : none
* Description :
* Reads the temperature value from the BMP180 as celsius, then
* converts it to fahrenheit.
*==============================================================================
*/
char * getTemp()
{
char buffer[4];
FILE * filePtr;
float result;
float celsiusValue;
float fahrenheitValue;
static char temperatureF[7];
filePtr = fopen (TEMPERATURE_FILE ,"r"); //r:Open a file for reading
fread(buffer, sizeof(char), 4, filePtr);
fclose (filePtr);
result = atof(buffer);
celsiusValue= (result /10);
fahrenheitValue=((celsiusValue*9)/5)+32; //celsius to farenheit conversion
sprintf(temperatureF, "%.1f",fahrenheitValue); //float to string conversion
strcat(temperatureF, " F"); //append fahrenheit units
return temperatureF;
}
/*==============================================================================
* Function : getPressure
* Return : pressureInHG: static char array
* Parameters : none
* Description :
* Reads the barometric pressure value in as Pascal from the BMP180
* then converts it to inches of mercury.
*==============================================================================
*/
40. 40
char * getPressure()
{
char buffer[6];
FILE * filePtr;
float result; //units = Pascal
float hPaValue; //units = hectopascal
float pressureValue; // units = inches of mercury
float conversionNum = 0.0295301;
static char pressureInHG[11];
filePtr = fopen (PRESSURE_FILE,"r"); //r:Open a file for reading
fread(buffer, sizeof(char), 6, filePtr);
fclose (filePtr);
result = atof(buffer); //string to float conversion
hPaValue = (result /100); //Pascal to hectopascal
pressureValue= hPaValue*conversionNum; //conversion to inches of mercury
sprintf(pressureInHG, "%.2f",pressureValue); //float to string conversion
strcat(pressureInHG, " inHg"); //append inches of mercury units
return pressureInHG;
}
