first version of project11

first iteration of project11 with first version of the various
source files to access wiringPi functionality for digitalWrite()
and digitalRead() of pins as well as 1602 LCD screen interface.

project11/lcd1602.c

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+/********************************************************************************************
+*Filename      : i2c1602_lcd.c
+*Description   : test iic 1602 lcd
+*Author        : Alan
+*Website       : www.osoyoo.com
+*Update        : 2017/07/03
+********************************************************************************************/
+
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <wiringPi.h>
+#include <wiringPiI2C.h>
+
+static int LCDAddr = 0x27;   // I2c LCD address, use sudo i2cdetect -y 1 after hooking up 1602
+static int BLEN = 1;         // 1--open backlight. 0--close backlight
+static int fd;               // I2C device linux file descriptor
+
+static void sendNibble (int bl, int rs, int rw, int data)
+{
+    int buf = (data & 0x0F) << 4;  // data nibble in upper nibble of byte
+
+    // set the command pins data in the lower nibble of byte
+    buf |= (bl) ? 0x08 : 0;    // set backlight on/off value
+    buf |= 0x04;               // EN = 1, RW = 0, RS = 0
+    buf |= (rw) ? 0x02 : 0;    // set RW value
+    buf |= (rs) ? 0x01 : 0;    // set RS value
+    wiringPiI2CWrite (fd, buf);
+
+    delay (2);
+
+    buf &= 0xFB;               // Make EN = 0 to turn off latch
+    wiringPiI2CWrite (fd, buf);
+}
+
+//send command to lcd
+static void send_command(int comm)
+{
+    // Send upper nibble, bit 7-4 firstly
+    sendNibble (BLEN, 0, 0, comm >> 4);
+
+    // Send lower nibble, bit 3-0 secondly
+    sendNibble (BLEN, 0, 0, comm);
+}
+
+//send data (text character) to lcd
+static void send_data(int data){
+    // Send upper nibble, bit 7-4 firstly
+    sendNibble (BLEN, 1, 0, data >> 4);
+
+    // Send lower nibble, bit 3-0 secondly
+    sendNibble (BLEN, 1, 0, data);
+}
+
+//clear screen
+void lcd1602Clear(void)
+{
+    send_command (0x01); //clear display, set cursor to home position
+}
+
+//Print the message on the lcd
+//initialize the lcd
+static void init1602 (void)
+{
+    send_command (0x33); // Must initialize to 8-line mode at first
+    delay (5);
+
+    send_command (0x32); // Then initialize to 4-line mode
+    delay (5);
+
+    send_command (0x28); // 4 bit mode, 2 Lines and 5x7 pixels character size
+    delay (5);
+
+    send_command (0x0C); // Enable display without cursor
+    delay (5);
+
+    lcd1602Clear ();
+    wiringPiI2CWrite (fd, 0x08);  // turn on backlight of LCD
+}
+
+void lcd1602Write (int xCol, int yRow, const char data[])
+{
+    int len = strlen (data);
+
+    // 16 columns per row
+    if (xCol < 0)  xCol = 0;
+    if (xCol > 15) xCol = 15;
+
+    // only two rows or lines, row 0 and row 1
+    if (yRow < 0)  yRow = 0;
+    if (yRow > 1)  yRow = 1;
+
+    // Move cursor to either row 0 or row 1
+    // row 0 -> 0x80 + xCol, row 1 -> 0xC0 + xCol
+    int addr = 0x80 + 0x40 * yRow + xCol;
+    send_command (addr);
+
+    int i;
+    for (i = 0; i < len; i++){
+        send_data (data[i]);
+    }
+}
+
+void lcd1602Writef (int xCol, int yRow, const char *format, ... )
+{
+    char  buff[256];
+
+    va_list  args;
+    va_start (args, format);
+    vsprintf (buff, format, args);
+    va_end (args);
+
+    lcd1602Write (xCol, yRow, buff);
+}
+
+int lcd1602Open(int lcdAddr)
+{
+
+    //init I2C 
+    fd = wiringPiI2CSetup (lcdAddr);
+    if (fd < 0) {
+        return 1;
+    }
+
+    init1602 ();
+
+    return 0;
+}
+
+int lcd1602Close (void)
+{
+    lcd1602Clear ();
+    close (fd);
+}

project11/lcd1602.h

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+
+//clear screen
+void lcd1602Clear(void);
+void lcd1602Write (int xCol, int yRow, const char data[]);
+void lcd1602Writef (int xCol, int yRow, const char *format, ... );
+int lcd1602Open(int lcdAddr);
+int lcd1602Close(void);
+

project11/pinreadwrite.c

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+
+#include <wiringPi.h>
+
+#include "pinreadwrite.h"
+
+void pinSetupWrite (int iPin, int iLevel)
+{
+    pinMode (iPin, OUTPUT);       // set the pin function
+    digitalWrite (iPin, iLevel);  // make sure the buzzer is off
+}
+
+void pinWriteHiLo (int iPin, int iCount, int iDelayHigh, int iDelayLow)
+{
+    for ( ; iCount > 0; iCount--) {
+        digitalWrite (iPin, HIGH);
+        delay (iDelayHigh);
+        digitalWrite (iPin, LOW);
+        delay (iDelayLow);
+    }
+    digitalWrite (iPin, LOW);
+}
+
+void pinWriteLoHi (int iPin, int iCount, int iDelayLow, int iDelayHigh)
+{
+    for ( ; iCount > 0; iCount--) {
+        digitalWrite (iPin, LOW);
+        delay (iDelayHigh);
+        digitalWrite (iPin, HIGH);
+        delay (iDelayLow);
+    }
+    digitalWrite (iPin, HIGH);
+}
+
+
+int pinRead (int iPin)
+{
+    return digitalRead (iPin);
+}
+
+void pinSetupRead (int iPin)
+{
+    pinMode (iPin, INPUT);    // set the pin function
+}
+
+void pinCleanup (int iPin)
+{
+    pinMode (iPin, INPUT);     // set the pin function
+    digitalWrite (iPin, LOW);  // make sure the buzzer is off
+}

project11/pinreadwrite.h

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+
+// functions to set a pin to INPUT or to OUTPUT and to set
+// the output level, HIGH or LOW.
+
+// set the specified pin as an OUTPUT pin for writing and initialize
+// the pin to the specified level, HIGH or LOW, for its initial conditions.
+void pinSetupWrite (int iPin, int iLevel);
+
+// for the number of times specified by the value of iCount, vary
+// the signal level of the specified pin.
+// These two functions have a loop where the output level of the pin
+// is set then a delay then the output level of the pin is set followed
+// by another delay.
+// 
+// Output level is: HIGH, delay, LOW, delay.
+// pin is left at LOW when function returns.
+void pinWriteHiLo (int iPin, int iCount, int iDelayHigh, int iDelayLow);
+
+// Output level is: LOW, delay, HIGH, delay.
+// pin is left at HIGH when function returns.
+void pinWriteLoHi (int iPin, int iCount, int iDelayLow, int iDelayHigh);
+
+void pinSetupRead (int iPin);
+int pinRead (int iPin);
+
+void pinCleanup (int iPin);

project11/tiltbuzz_1.c

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+
+#include <wiringPi.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "lcd1602.h"
+#include "pinreadwrite.h"
+
+int main (int argc, char *argv[])
+{
+        // BUZZPIN is wiringPi Pin #1 or physical pin #12 or GPIO #18
+        int BUZZPIN = 0;
+
+	if (wiringPiSetup() == -1) {
+		printf ("Setup wiringPi Failed!\n");
+		return -1;
+	}
+
+	lcd1602Open (0x27);
+
+	pinSetupWrite (BUZZPIN, LOW);
+
+	lcd1602Write (0, 0, "Welcome tilter");
+	delay (2000);
+
+	lcd1602Clear ();
+
+	int  iCount = 20;
+	for ( ; iCount > 0; iCount--) {
+		int  iDelay = ((iCount % 5) + 1) * 400;
+
+		lcd1602Writef (0, 0, "tiltbuzz_1 %2.2d", iCount);
+		pinWriteHiLo (BUZZPIN, 1, iDelay, iDelay);
+	}
+
+	// clean up the GPIO resources we have been using.
+	// make sure that things are back to a good state before exit.
+	pinCleanup (BUZZPIN);
+	lcd1602Close();
+
+	delay (500);
+	return 0;
+}