why my arduino doesnt recognize the characters? - arduino

I have a problem with my Bluetooth module on my Arduino, I am trying to do a door that opens with a button in an application in the phone but when I press the button in the app the door doesn't move.
#include <SoftwareSerial.h>
#include <Servo.h>
int mover;
int mover2;
Servo servoMotor1;
Servo servoMotor2;
char rxChar;
SoftwareSerial BTserial(10, 11);
void setup(){
Serial.begin(9600);
Serial.println("Bluetooth test program");
pinMode (4,INPUT);//Fin de carrera 1
pinMode (2,INPUT);//Fin de carrera 2
mover=90; //0 Abrir 180 Cerrar 60-120 Velocidades
mover2=150;//motor Cerradura
servoMotor1.attach(8);//Motor Pin8
servoMotor2.attach(9);//Motor Pin9
BTserial.begin(9600);
BTserial.println("Bluetooth test program");
}
void loop() {
int lectura;
int lectura2;
servoMotor1.write(mover);
servoMotor2.write(mover2);
lectura=digitalRead(4);//fin de carrera
lectura2=digitalRead(2);//fin de carrera
if (Serial.available())
{
BTserial.write(Serial.read());
}
if (BTserial.available())
{
Serial.write(BTserial.read());
char rxChar = BTserial.read();
}
if(rxChar=='a'){
Serial.print("60 Grados");
mover=60;
}
if(rxChar=='b'){
Serial.print("120 Grados");
mover=120;
}
if (lectura==LOW and mover==120){
mover=90;//motor frena
mover2=30;//Motor Cerradura Cerrado
}
if (lectura2==LOW and mover==60){
mover=90;//motor frena
}
}
when I press the button the console returns "⸮"

This line is wrong: char rxChar = BTserial.read(); because you are declaring a local rxChar and assigning the read character to it. But, because it is local (inside { } ) its value will be lost. And because you also have a global rxChar (line 7: char rxChar;) that is unassigned, you will be using that value everywhere else.
Also, as mentioned you are reading from BTSerial twice.
You can fix the problem by simply removing "char" in the line mentioned, so rxChar will refer to the global declaration, and
perform only one read: rxChar = BTserial.read(); Serial.write(rxChar);

Related

SPI Micro SD Card - error opening textfile - why isn't it working?

First of all sorry for my bad english and my programming skills... im still a beginner. I have a problem implementing the example code into my project. The example code for Datalogging on my SD-Card works. So there are no wiring faults.. Implementing this working code in my project, the arduino cant find the text data and i dont know why. can anybody help me ?
im working with an arduino nano V3. and a SPI Card Reader.
Here is what happening in the serial monitor:
Initializing SD card...card initialized.
error opening datalog.txt
Here is my Code - sorry for the used German words... but i think they wont disturb.
#include <LiquidCrystal_I2C.h>
#include "RTClib.h"
RTC_DS3231 rtc;
#include <SimpleDHT.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#include <SPI.h>
#include <SD.h>
const int chipSelect = 10; // SD KARTE
int pinDHT22 = 2; // Kombisensor
SimpleDHT22 dht22(pinDHT22);
float temperature = 0;
float humidity = 0;
volatile float windgeschwindigkeit = 0;
unsigned long previousMillis = 0;
volatile int Impulscounter = 0; // Impulszähler für Windgeschwindigkeit
unsigned long windmillis = 0;
int a = 0;
File Datenlog;
void wind()
{
Impulscounter = Impulscounter + 1;
if( Impulscounter == 1)
{
windmillis = millis();
}
}
void setup()
{
pinMode(3, INPUT);
lcd.begin();
lcd.backlight();
Serial.begin(9600);
attachInterrupt(1, wind, RISING);
while (!Serial) { // wait for serial port to connect. Needed for native USB port only
;
}
Serial.print("Initializing SD card...");
if (!SD.begin(chipSelect)) { // see if the card is present and can be initialized:
Serial.println("Card failed, or not present");
// don't do anything more:
while (1);
}
Serial.println("card initialized.");
Datenlog = SD.open("test.txt", FILE_WRITE);
if (Datenlog){
Datenlog.print("Tag "); // ... und die Textdatei anschließend befüllt werden.
Datenlog.print("Datum ");
Datenlog.print("Uhrzeit ");
Datenlog.print("Aussentemperatur ");
Datenlog.print("Aussenfeuchtigkeit ");
Datenlog.print("Windgeschwindigkeit ");
Datenlog.print("Gehaeusetemperatur ");
Datenlog.close();
Serial.print ( "it worked");
}
else {
Serial.println("error opening datalog.txt");
}
}

Need some help in understanding some codes

I'm using RFID RC522 module in Arduino what the code does is, whenever the RFID tag is close to the reader it will read the tag no, with the current timestamp. But i need help in understanding the code line by line. I've understood a few lines which commented in the code but the rest i need help. Thank you
#include <RFID.h>
#include <SPI.h>
#define SS_PIN 10
#define RST_PIN 9
RFID rfid(SS_PIN, RST_PIN);
int serNum[4];
String cardno;
int interval = 15000; // millisec
long now = 0;
long lasttime = millis(); //millis() no.of millisec the sketch was runnning
String readerID = "100"; // This is the reader ID
void setup() {
Serial.begin(9600); //setting data rate in bits per second 9600
SPI.begin();
rfid.init();
}
void loop() {
now = millis();
if (rfid.isCard()) {
if (rfid.readCardSerial()) {
lasttime = now;
cardno = String(rfid.serNum[0]) +
String(rfid.serNum[1]) +
String(rfid.serNum[2]) +
String(rfid.serNum[3]) +
String(rfid.serNum[4]);
Serial.print(readerID);
Serial.print(":");
Serial.println(cardno); //printing the cardno in the serial monitor
}
}
rfid.halt();
delay(1000);
}
There are unused variables in your code. Let's get rid of them so that it is less confusing. I also added comments that explain the if statements.
#include <RFID.h>
#include <SPI.h>
#define SS_PIN 10
#define RST_PIN 9
RFID rfid(SS_PIN, RST_PIN);
String cardno;
String readerID = "100";
void setup() {
Serial.begin(9600);
SPI.begin();
rfid.init();
}
void loop() {
if (rfid.isCard()) { // Look for a card. If found, return true.
if (rfid.readCardSerial()) { // Read the serial number of the card. if successful, return true.
cardno = String(rfid.serNum[0]) +
String(rfid.serNum[1]) +
String(rfid.serNum[2]) +
String(rfid.serNum[3]) +
String(rfid.serNum[4]);
Serial.print(readerID);
Serial.print(":");
Serial.println(cardno);
}
}
rfid.halt();
delay(1000);
}
Guessing from your comment, I think you want to understand how RFID class is implemented. I suggest looking at RFID.h and RFID.cpp.
RFID class has an array called serNum. My guess is that when you call readCardSerial(), an instance of RFID tries to store a card number in this array. If the operation is successful, it returns true.

Start/Stop a function using pushbutton

I am trying to display the readings of LDR on my 0.96" Adafruit OLED. I have succeeded with obtaining that results.
Now I want to start the display of the reading only when I push the button and stop it once I push it again. This should go on a loop.
I tried to draft a code for that:
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
int sensorPin = A0; // select the input pin for ldr
int sensorValue = 0;
boolean state = false;
int buttonpin;
#define OLED_RESET 4 // not used / nicht genutzt bei diesem Display
Adafruit_SSD1306 display(OLED_RESET);
char inChar;
String string;
void setup() {
pinMode(13, OUTPUT);
buttonpin = 2; //whatever pin your button is plugged into
pinMode(buttonpin, INPUT_PULLUP);
// initialize with the I2C addr 0x3C / mit I2C-Adresse 0x3c initialisieren
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
Serial.begin(9600);
display.display();
delay(2000);
display.clearDisplay();
display.setTextColor(INVERSE);
}
void loop()
{
while (state == false)
{
if (digitalRead(buttonpin) == HIGH)
{
display.clearDisplay();
sensorValue = analogRead(sensorPin);
Serial.println(sensorValue);
display.setCursor(30,0);
display.setTextSize(1);
display.print("LDR Reading:");
display.setCursor(30,10);
display.setTextSize(2);
display.print(sensorValue);
delay(500);
display.display();
state = false;
}
}
}
But the screen starts displaying the results only when I keep the push button pressed continuously and when I release the button , the program halts with the last reading displayed on the screen.
I need the results as follows:
1st press: starts displaying readings
2nd press: screen should be blank. (display.clearDisplay() does that job)
I am unfamiliar with the usage of switch case in Arduino.
Thie is to elaborate on #shaunussain's answer.
Here is an exampole of a toggle:
Create a boolean variable : bool toggle = false; The variable state is at false at the beginning. Thus, the screen will start blank.
Then do something like this. This is just a logic.
If the button is pressed
if( buttonPressed() ) {
Change toggle's state. So if it was ON / true, it will change to OFF / false.
toggle = !toggle;
Now, we wait until the button has been released, otherwise the code might go a little crazy! And then we close the brackets.
while ( buttonPressed() );
}
Then in your loop, you will have a switch case. We start by innitializing the switch case.
switch( toggle ) {
Then we set up a case for when the toggle is on ON / true. 1 is true, 0 is false.
case 1 :
Then we write the code body.
displayTextOnScreen();
Then we exit the switch case because toggle matched with our case.
break;
Then, if we toggle isn't true or it is something else (because there was a glitch in the code), we will have a default case.
default:
In the default, we want the screen to be off, so if it isn't suppose to be on, or if there is a bug, it will be off. Then we will close the switch case and exit it because default is the last possible case in a switch case.
display.clearDisplay();
}
Thank you so much, it helped me a lot. The code is working fine. Updated code :
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
int sensorPin = A0; // select the input pin for ldr
int sensorValue = 0;
bool toggle = false;
int buttonpin;
#define OLED_RESET 4 // not used / nicht genutzt bei diesem Display
Adafruit_SSD1306 display(OLED_RESET);
char inChar;
String string;
void setup() {
pinMode(13, OUTPUT);
buttonpin = 2;
pinMode(buttonpin, INPUT_PULLUP);
// initialize with the I2C addr 0x3C / mit I2C-Adresse 0x3c initialisieren
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
Serial.begin(9600);
display.display();
delay(2000);
display.clearDisplay();
display.setTextColor(INVERSE);
}
void loop()
{
if (digitalRead(buttonpin) == HIGH)
{
toggle = !toggle;
while(digitalRead(buttonpin) == HIGH);
}
switch( toggle )
{
case 1:
display.clearDisplay();
sensorValue = analogRead(sensorPin);
Serial.println(sensorValue);
display.setCursor(30,0);
display.setTextSize(1);
display.print("LDR Reading:");
display.setCursor(30,10);
display.setTextSize(2);
display.print(sensorValue);
delay(500);
break;
case 0:
display.clearDisplay();
break;
}
display.display();
}
Keep a Boolean to track the toggle state and a Boolean to keep the state of the button from the previous loop. If the button goes from low to high between loop iterations then update the toggle Boolean,
toggle = !togggle
Base your condition for the display state then on the toggle instead of directly on the button.

Read/Write EEPROM Arduino

I have a new ATmega328P CH340G Arduino Uno R3 board.
When I input a two-digit number (like 29), after power off and power on, the board shows only one digit (only 9). I want to show two digits.
enter image description here
Can you help me?
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <EEPROM.h>
int addr = 5;
LiquidCrystal_I2C lcd(0x27,16,2);
void setup() {
lcd.init();
Serial.begin(9600);
// initialize the lcd
// Print a message to the LCD.
lcd.backlight();
lcd.setCursor(0,0);
lcd.write(EEPROM.read(addr));
}
void loop() {
if (Serial.available()) {
while (Serial.available() > 0) {
char myValue = Serial.read();
EEPROM.write(addr,myValue);
lcd.write(myValue);
}
}
}
You are always writing to the same addr (i.e. 5) so you are most likely overwriting the previous character. Try incrementing your address after a write like this:
EEPROM.write(addr++, myValue);
(notice the ++ to increment the address)

displaying Hexadecimal value in LCD

I wrote LCD interface program for Atmega328 (Though there are libraries available, I wanted to write from scratch). But have two problems.
1. Sometimes LCD does not display correctly. Only few strips are seen. I end up in resetting once or twice.
2. I am unable to display hexadecimal values usingdisplayOneByteHexValue(). However ASCII coversion was correct and I could see that in Atmel Simulator. Below is the code. I am using Atmel Studio 6.2
/*
* EmbeddedProgram1.c
*
* Created: 16-05-2015 08:19:38
* Author: Mahesha
*/
#ifndef F_CPU
#define F_CPU 8000000UL
#endif
#include <avr/io.h>
#include <util/delay.h>
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Only Change following when changing pin numbers.
// All Data bits have to be assigned sequentially in same the port . RS and EN must be allocated in the same port
#define LCDPORT PORTD
#define LCDDDR DDRD
// used pins on port appropriate ports
#define LCD_DB4 2 // PORTD.2
#define LCD_DB5 3 // PORTD.3
#define LCD_DB6 4 // PORTD.4
#define LCD_DB7 5 // PORTD.5
#define LCD_ENABLE_BIT 6 // PORTD.6 Enable
#define LCD_RS 7 // PORTD.7 Register Select
//#define LCD_RW // R/W is connected to GND permanently
#define LCD_DATA_BITS_MASK 0x3C
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#define SET_EIGHT_BIT_MODE() LCDPORT|=((1<<LCD_DB5)|(1<<LCD_DB4)) // Set DB4 and DB5 as 1 for setting eight bit mode.
#define SET_FOUR_BIT_MODE() LCDPORT|=(1<<LCD_DB5)
#define SET_INSTRUCTION_MODE() LCDPORT&=~(1<<LCD_RS) //Function to select command port on LCD RS pin bit 2
#define SET_DATA_MODE() LCDPORT|=(1<<LCD_RS) //Function to select data port on LCD
#define DISABLE_LCD() LCDPORT&=~(1<<LCD_ENABLE_BIT) //Function to disable LCD P0.18
#define ENABLE_LCD() LCDPORT|=(1<<LCD_ENABLE_BIT) //Function to Enable LCD P0.18
//#define EIGHT_BIT_MODE 0x30 // 0 0 1 1 x x x x DB7 to DB0 0f LCD
#define BUSY_FLAG_WAIT_TIME 20
#define FOUR_BIT_5_BY_10_2LINE 0x28
#define LCD_INIT_DELAY 100 // Give a delay of 200 msec after reset. // Datasheet says 10 msec delay.
//Commands Finalized
#define CLEAR_DISPLAY 0x01
#define CURSOR_HOME 0x02 // return home
#define ENTRY_MODE_LEFT_TO_RIGHT 0x06 // Cursor direction from Left to right , Bit 1 of entry mode in LCD
#define DISPLAY_OFF 0x08 // Blink ON, Cursor ON etc are don't care
#define CURSOR_OFF_BLINK_OFF 0x0C
#define CURSOR_OFF_BLINK_ON 0x0D // blink on Even 0x0D also works. So cursor need not be ON
#define CURSOR_ON_BLINK_OFF 0x0E // blink off
#define CURSOR_ON_BLINK_ON 0x0F
#define SHIFT_ENTIRE_LEFT 0x18
#define SHIFT_CURSOR_LEFT 0x10
#define SHIFT_ENTIRE_RIGHT 0x1C
#define SHIFT_CURSOR_RIGHT 0x14
// Function prototypes
void unpackAndSend(char data);
void waitForBusyFlagToClear(void);
void sendLCDPulse(void);
void displayInRow1(char* data);
void displayInRow2(char* data);
void displayInRow1WithPosition(char* data, uint8_t position);
void displayInRow2WithPosition(char* data, uint8_t position);
void sendTextToLCD(char *data);
void displayOneByteHexValue(unsigned char,unsigned char,char);
void initializeLCD(void);
void CL_delayMS(unsigned int delayMS)
{
while(delayMS--)
{
_delay_ms(1);
}
}
void CL_delayuS(unsigned int delayus)
{
while(delayus--)
{
_delay_us(1);
}
}
// writes a char to the LCD
void writeCharToLCD(unsigned char data)
{
SET_DATA_MODE(); // RS bit has to be 1 for data mode
unpackAndSend(data);
}
// sendLCD pulse will just enable and disable the EN bit of LCD display.
void sendLCDPulse(void)
{
DISABLE_LCD();
CL_delayuS(50);
ENABLE_LCD();
CL_delayMS(1);
DISABLE_LCD();
CL_delayMS(1);
}
// writes an instruction to the LCD
void sendLCDCommand(unsigned char inst)
{
SET_INSTRUCTION_MODE();
unpackAndSend(inst);
waitForBusyFlagToClear();
}
// Unpack and send data will separate two nibbles and send twice.
void unpackAndSend(char inst)
{
char temp=inst;
DISABLE_LCD();
// SET_WRITE_MODE(); // If write is permanently disabled, do not use this.
LCDPORT &= (~LCD_DATA_BITS_MASK); // Clear the data bits
//sendLCDPulse();
inst&=0xF0;
inst=inst>>4; // Get the upper nibble
LCDPORT|=inst<<LCD_DB4; //Replace the bits starting from position of bit LCD_DB4 with this new data
sendLCDPulse();
LCDPORT &= (~LCD_DATA_BITS_MASK); // Clear the data bits again
//sendLCDPulse();
temp &=0x0f; //send low nibble
LCDPORT|=temp<<LCD_DB4;
sendLCDPulse();
}
// waitForBusyFlagToClear functio can wait for the busy bit, But since we are permanently connected R/W pin to ground, we cannot read
// the flag from LCD. In case busy bit has to be read, implementation has to be changed.
void waitForBusyFlagToClear(void)
{
CL_delayMS(BUSY_FLAG_WAIT_TIME);
}
// clear display
void clearDisplay(void)
{
sendLCDCommand (CLEAR_DISPLAY);
}
// return home
void returnCursorHome(void)
{
sendLCDCommand (CURSOR_HOME);
}
// LCD off
void displayOFF(void)
{
sendLCDCommand (DISPLAY_OFF);
}
// LCD on
void displayONCursorOFF(void)
{
sendLCDCommand (CURSOR_OFF_BLINK_OFF);
}
// cursor on
void displayONCursorON(void)
{
sendLCDCommand (CURSOR_ON_BLINK_OFF);
}
// blink on
void cursorOffBlinkOn(void)
{
sendLCDCommand (CURSOR_OFF_BLINK_ON);
}
// blink OFF, but display and cursors are ON
void cursorOnBlinkOff(void)
{
sendLCDCommand (CURSOR_ON_BLINK_OFF);
}
// All are ON
void cursorOnBlinkOn(void)
{
sendLCDCommand (CURSOR_ON_BLINK_ON);
}
//go to first line
void LCDline1 (void)
{
sendLCDCommand (0b10000000);
}
//go to second line
void LCDline2 (void)
{
sendLCDCommand (0b11000000);
}
// goto position x,y
// row1 or row2 are the parameters
// So parameters can be 1 or 2
void setRowAndColumnPositionOnDisplay (unsigned char rowNumber, unsigned char position)
{
unsigned char pos;
if (rowNumber == 1)
{
pos = 0x00 + position;
pos|=0x80; // Command to set 1st Row.
}
else //if (rowNumber == 1) // Either row 1 or two. We cannot have else option.
{
pos = 0x40 + position;
pos|=0xC0; // Command to set second row.
}
sendLCDCommand (pos);
}
void displayInRow1(char* data)
{
sendLCDCommand(0x80); // Set DDRAM Address as 0
sendTextToLCD(data);
}
void displayInRow1WithPosition(char* data, unsigned char position)
{
// The position cannot be more than 15. Display is 16 characters (0-15).
if(position>15)
{
position = 15;
}
sendLCDCommand(0x80|position); // Change the DDRAM address to first line by
// keeping D7 high and setting address to 0 onwards
sendTextToLCD(data);
}
////////////////////////////// diaplayInRow2 /////////////////////////////////////////////
void displayInRow2(char* data)
{
sendLCDCommand(0xC0); // Change the DDRAM address to next line 0x40 to 4F
sendTextToLCD(data);
}
////////////////////// diaplayInRow2WithPosition //////////////////////
void displayInRow2WithPosition(char* data, unsigned char position)
{
// The position cannot be more than 15. Display is 16 characters (0-15).
if(position>15)
{
position = 15;
}
sendLCDCommand(0xC0|position); // Change the DDRAM address to second line by
//keeping Bit D7 high and setting address at 0x40 onwards
sendTextToLCD(data);
}
void scrollLcd(char *row1Data,char *row2Data)
{
while(1)
{
sendLCDCommand(SHIFT_CURSOR_LEFT);
sendLCDCommand(SHIFT_ENTIRE_LEFT);
CL_delayMS(200);
}
}
//write text to the LCD
void sendTextToLCD(char *data)
{
while (*data)
{
writeCharToLCD(*data);
data++;
}
}
// Function to convert lower nibble to ASCII Value
//Only lower nibble of the input is considered and higher nibble is lost
char convertLowerNibbleToASCIIValue(char data)
{
data&=0x0F;
if(data<=9)
{
return(data+0x30);
}
else // There is no chance for getting more than 0x0F in the lowerNibble Parameter)
{
return(data+0x37);
}
}
// Function to convert Higher nibble to ASCII Value
//Only higher nibble of the input is considered and lower nibble is lost
char convertHigherNibbleToASCIIValue(char data)
{
data>>=4;
if(data<=9)
{
return(data+0x30);
}
else // There is no chance for getting more than 0x0F in the lowerNibble Parameter)
{
return(data+0x37);
}
}
void displayOneByteHexValue(unsigned char rowNum, unsigned char pos, char data)
{
char temp;
setRowAndColumnPositionOnDisplay(rowNum,pos);
temp = convertHigherNibbleToASCIIValue(data);
sendTextToLCD(&temp);
temp = convertLowerNibbleToASCIIValue(data);
sendTextToLCD(&temp);
}
// init LCD
void initializeLCD(void)
{
// Set the direction of port pins connected to LCD display as output ports.
// We are permanently connecting R/W pin to ground. So there is no read instruction in this case..
LCDDDR |= (1<<LCD_DB4)|(1<<LCD_DB5)|(1<<LCD_DB6)|(1<<LCD_DB7)|(1<<LCD_RS)|(1<<LCD_ENABLE_BIT);
//After reset, data sheet suggests some delay.
CL_delayMS(LCD_INIT_DELAY);
// Note some sites says three times 8 bit mode setting commands need to be sent.
// But it is observed that even without this, LCD works fine. So 1st Command, 2nd Command and 3rd Commands can be deleted below.
//ENABLE_LCD();
// 1st Command
SET_EIGHT_BIT_MODE();
//sendLCDPulse(); // Do not delete this. Need to further analyse. If pulse if sent it is not working
//CL_delayMS(5); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
_delay_ms(5);
// Second Command
SET_EIGHT_BIT_MODE();
//sendLCDPulse();
_delay_us(100);
//CL_delayuS(100); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
// third Command
SET_EIGHT_BIT_MODE();
//sendLCDPulse();
//CL_delayuS(100); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
_delay_us(37);
// Finally Set four bit mode
SET_FOUR_BIT_MODE();
//sendLCDPulse();
CL_delayuS(100);
// First time when 4 bit mode command is sent, only one higher nibble was sent since
// only 4 bits are connected from MPU to LCD. Since D0 to D3 of LCD are not connected,
// their values depend on how the pins are connected in LCD module (May be grounded, may kept open etc)
//So again send function set command to set 2 line display mode mode and 5x7 character mode. But now two write operations to LCD is made
// inside the function sendLCDCommand.
sendLCDCommand (FOUR_BIT_5_BY_10_2LINE);
//turn on display and cursor OFF, Blink OFF (sent two times using below command)
sendLCDCommand (CURSOR_OFF_BLINK_OFF);
//clr display
sendLCDCommand (CLEAR_DISPLAY);
// Set Entry mode left to right
sendLCDCommand (ENTRY_MODE_LEFT_TO_RIGHT);
}
void LCDProgramCallFromMain(char *row1Data, char *row2Data)
{
initializeLCD();
setRowAndColumnPositionOnDisplay (1,0);
sendTextToLCD (row1Data);
displayOneByteHexValue(2,0,0xF4);
//setRowAndColumnPositionOnDisplay (2,5);
//displayInRow1(row1Data);
}
int main(void)
{
LCDProgramCallFromMain("Hello", "Welcome to cloude");
while(1)
{
}
}
Below is the image of the display I am getting. Not able to makeout where the problem is.
Yes, it worked after I changed the function as below. Thanks for the help.
void displayOneByteHexValue(unsigned char rowNum, unsigned char pos, char data)
{
char temp;
setRowAndColumnPositionOnDisplay(rowNum,pos);
temp = convertHigherNibbleToASCIIValue(data);
writeCharToLCD(temp);
temp = convertLowerNibbleToASCIIValue(data);
writeCharToLCD(temp);
}
I further optimized the code and below is the complete working code with small demo function called from main.
#ifndef F_CPU
#define F_CPU 16000000UL
#endif
#include <avr/io.h>
#include <util/delay.h>
#include <stdlib.h>
#include <avr/sfr_defs.h>
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Only Change following when changing pin numbers.
// All Data bits have to be assigned sequentially in same the port . RS and EN must be allocated in the same port
#define LCDPORT PORTD
#define LCDDDR DDRD
// used pins on port appropriate ports
#define LCD_DB4 2 // PORTD.2
#define LCD_DB5 3 // PORTD.3
#define LCD_DB6 4 // PORTD.4
#define LCD_DB7 5 // PORTD.5
#define LCD_ENABLE_BIT 6 // PORTD.6 Enable
#define LCD_RS 7 // PORTD.7 Register Select
//#define LCD_RW // R/W is connected to GND permanently
#define LCD_DATA_BITS_MASK ((1<<LCD_DB4)|(1<<LCD_DB5)|(1<<LCD_DB6)|(1<<LCD_DB7))
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*
#define SET_EIGHT_BIT_MODE() LCDPORT|=((1<<LCD_DB5)|(1<<LCD_DB4)) // Set DB4 and DB5 as 1 for setting eight bit mode.
#define SET_FOUR_BIT_MODE() LCDPORT|=(1<<LCD_DB5)
*/
#define SET_INSTRUCTION_MODE() LCDPORT&=~(1<<LCD_RS) //Function to select command port on LCD RS pin bit 2
#define SET_DATA_MODE() LCDPORT|=(1<<LCD_RS) //Function to select data port on LCD
#define DISABLE_LCD() LCDPORT&=~(1<<LCD_ENABLE_BIT) //Function to disable LCD P0.18
#define ENABLE_LCD() LCDPORT|=(1<<LCD_ENABLE_BIT) //Function to Enable LCD P0.18
#define BUSY_FLAG_WAIT_TIME 20
#define FOUR_BIT_5_BY_10_2LINE 0x28
#define LCD_INIT_DELAY 100 // Give a delay of 100 msec after reset. // Datasheet says 10 msec delay.
// Function prototypes for external use (to be kept in Header file)
void sendLCDCommand(unsigned char cmd);
void displayInRow1(unsigned char* data);
void displayInRow2(unsigned char* data);
void displayInRow1WithPosition(unsigned char* data, uint8_t position);
void displayInRow2WithPosition(unsigned char* data, uint8_t position);
void sendTextToLCD(unsigned char *data);
void initializeLCD(void);
// Function prototypes for file use (only internal)
void unpackAndSend(char data);
void waitForBusyFlagToClear(void);
void sendLCDPulse(void);
void displayOneByteHexValue(unsigned char,unsigned char,char); // This function is no longer needed. Only for demo purpose.
// #define commands are replaced by enums to demonstrate the feature of enumerated data types
enum DISPLAY_PROPERTY
{
CLEAR_DISPLAY=0x01,
CURSOR_HOME = 0x02, // return home
ENTRY_MODE_LEFT_TO_RIGHT= 0x06, // Cursor direction from Left to right , Bit 1 of entry mode in LCD
DISPLAY_OFF= 0x08, // Blink ON, Cursor ON etc are don't care
CURSOR_OFF_BLINK_OFF= 0x0C,
CURSOR_OFF_BLINK_ON= 0x0D, // blink on Even 0x0D also works. So cursor need not be ON
CURSOR_ON_BLINK_OFF=0x0E, // blink off
CURSOR_ON_BLINK_ON=0x0F,
SHIFT_ENTIRE_LEFT= 0x18,
SHIFT_CURSOR_LEFT= 0x10,
SHIFT_ENTIRE_RIGHT= 0x1C,
SHIFT_CURSOR_RIGHT= 0x14,
};
void SET_EIGHT_BIT_MODE(void)
{
LCDPORT=(LCDPORT&(~LCD_DATA_BITS_MASK))|((0<<LCD_DB7)|(0<<LCD_DB6)|(1<<LCD_DB5)|(1<<LCD_DB4)); // Set DB4 and DB5 as 1 for setting eight bit mode.
}
void SET_FOUR_BIT_MODE(void)
{
LCDPORT= (LCDPORT&(~LCD_DATA_BITS_MASK)) | ((0<<LCD_DB7)|(0<<LCD_DB6)|(1<<LCD_DB5)|(0<<LCD_DB4));
}
void CL_delayMS(unsigned int delayMS)
{
while(delayMS--)
{
_delay_ms(1);
}
}
void CL_delayuS(unsigned int delayus)
{
while(delayus--)
{
_delay_us(1);
}
}
// writes a char to the LCD
void writeCharToLCD(unsigned char data)
{
SET_DATA_MODE(); // RS bit has to be 1 for data mode
unpackAndSend(data);
}
// sendLCD pulse will just enable and disable the EN bit of LCD display.
void sendLCDPulse(void)
{
//DISABLE_LCD();
//CL_delayuS(50);
ENABLE_LCD();
CL_delayMS(1);
DISABLE_LCD();
CL_delayMS(1);
}
// writes an instruction to the LCD
void sendLCDCommand(unsigned char cmd)
{
SET_INSTRUCTION_MODE();
unpackAndSend(cmd);
waitForBusyFlagToClear();
}
// Unpack and send data will separate two nibbles and send twice.
void unpackAndSend(char inst)
{
char temp=inst;
DISABLE_LCD();
// SET_WRITE_MODE(); // If write is permanently disabled, do not use this.
LCDPORT &= (~LCD_DATA_BITS_MASK); // Clear the data bits
//sendLCDPulse();
inst&=0xF0;
inst=inst>>4; // Get the upper nibble
LCDPORT|=inst<<LCD_DB4; //Replace the bits starting from position of bit LCD_DB4 with this new data
sendLCDPulse();
LCDPORT &= (~LCD_DATA_BITS_MASK); // Clear the data bits again
//sendLCDPulse();
temp &=0x0f; //send low nibble
LCDPORT|=temp<<LCD_DB4;
sendLCDPulse();
}
// waitForBusyFlagToClear function can wait for the busy bit, But since we are permanently connected R/W pin to ground, we cannot read
// the flag from LCD. In case busy bit has to be read, implementation has to be changed.
void waitForBusyFlagToClear(void)
{
CL_delayMS(BUSY_FLAG_WAIT_TIME);
}
// goto position x,y
// row1 or row2 are the parameters
// So parameters can be 0 or 1
void setRowAndColumnPositionOnDisplay (unsigned char rowNumber, unsigned char position)
{
unsigned char pos;
if (rowNumber==0) // If Row is 0, display in 1st row
{
pos = 0x00 + position;
pos|=0x80; // Command to set 1st Row.
}
else //if (rowNumber == 1) // Either row 1 or two etc
{
pos = 0x40 + position;
pos|=0xC0; // Command to set second row.
}
sendLCDCommand (pos);
}
void displayInRow1(unsigned char* data)
{
sendLCDCommand(0x80); // Set DDRAM Address as 0
sendTextToLCD(data);
}
void displayInRow1WithPosition(unsigned char* data, unsigned char position)
{
sendLCDCommand(0x80|position); // Change the DDRAM address to first line by
// keeping D7 high and setting address to 0 onwards
sendTextToLCD(data);
}
////////////////////////////// diaplayInRow2 /////////////////////////////////////////////
void displayInRow2(unsigned char* data)
{
sendLCDCommand(0xC0); // Change the DDRAM address to next line 0x40 to 4F
sendTextToLCD(data);
}
////////////////////// diaplayInRow2WithPosition //////////////////////
void displayInRow2WithPosition(unsigned char* data, unsigned char position)
{
sendLCDCommand(0xC0|position); // Change the DDRAM address to second line by
//keeping Bit D7 high and setting address at 0x40 onwards
sendTextToLCD(data);
}
//write text to the LCD
void sendTextToLCD(unsigned char *data)
{
while (*data)
{
writeCharToLCD(*data);
data++;
}
}
// initialize LCD
void initializeLCD(void)
{
// Set the direction of port pins connected to LCD display as output ports
// We are permanently connecting R/W pin to ground. So there is no read instruction in this case
LCDDDR |= (1<<LCD_DB4)|(1<<LCD_DB5)|(1<<LCD_DB6)|(1<<LCD_DB7)|(1<<LCD_RS)|(1<<LCD_ENABLE_BIT);
//After reset, data sheet suggests some delay.
CL_delayMS(LCD_INIT_DELAY);
// Note some sites says three times 8 bit mode setting commands need to be sent.
// But it is observed that even without this, LCD works fine. So 1st Command, 2nd Command and 3rd Commands can be deleted below.
//ENABLE_LCD();
// 1st Command
SET_EIGHT_BIT_MODE();
sendLCDPulse(); // Do not delete this. Need to further analyze. If pulse if sent it is not working
//CL_delayMS(5); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
_delay_ms(5);
// Second Command
SET_EIGHT_BIT_MODE();
sendLCDPulse();
_delay_us(100);
//CL_delayuS(100); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
// third Command
SET_EIGHT_BIT_MODE();
sendLCDPulse();
//CL_delayuS(100); // Do not use this delay since delay is not acurate, Either use _delay_ms or use timers
_delay_us(37);
// Finally Set four bit mode
SET_FOUR_BIT_MODE();
sendLCDPulse();
CL_delayuS(100);
// First time when 4 bit mode command is sent, only one higher nibble was sent since
// only 4 bits are connected from MPU to LCD. Since D0 to D3 of LCD are not connected,
// their values depend on how the pins are connected in LCD module (May be grounded, may kept open etc)
//So again send function set command to set 2 line display mode mode and 5x7 character mode. But now two write operations to LCD is made
// inside the function sendLCDCommand.
sendLCDCommand (FOUR_BIT_5_BY_10_2LINE);
//turn on display and cursor OFF, Blink OFF (sent two times using below command)
sendLCDCommand (CURSOR_OFF_BLINK_OFF);
//clr display
sendLCDCommand (CLEAR_DISPLAY);
// Set Entry mode left to right
sendLCDCommand (ENTRY_MODE_LEFT_TO_RIGHT);
}
void displayNumberTest(int range)
{
float fNum = -0.332;
unsigned char lcdBuffer[50];
sendLCDCommand(CLEAR_DISPLAY);
//setRowAndColumnPositionOnDisplay (0,0);
//sendTextToLCD("Decimal = ");
for (int count=0;count<range;count++)
{
itoa(count,lcdBuffer,2);
setRowAndColumnPositionOnDisplay (1,0);
sendTextToLCD(lcdBuffer);
itoa(count,lcdBuffer,16);
setRowAndColumnPositionOnDisplay (1,13);
sendTextToLCD(lcdBuffer);
itoa(count,lcdBuffer,10);
setRowAndColumnPositionOnDisplay (0,0); // 1st Row, 0th position
sendTextToLCD(lcdBuffer);
// Now display some floating value number.
// use the function dtostrf(). It take 4 parameters
// Parameter1: The value to be converted
// 2: Width
//3. Precision
// 4. String to hold ASCII
// It is also possible to use sprintf function. But it takes more memory.
fNum=(fNum*(-1)*(count+1)/101.12)+0.012;
dtostrf(fNum,5,3,lcdBuffer);
setRowAndColumnPositionOnDisplay (0,7);
sendTextToLCD(lcdBuffer);
CL_delayMS(300);
}
}
// Scroll the display
// This program need to be modified further to display only whatever characters are there in DDRAM.
// Right now 4 columns will be shifted just to demonstrate.
void scrollingDisplayTest(unsigned char *row1Text, unsigned char* row2Text, unsigned int scrollDelay)
{
unsigned char count=40;
sendLCDCommand(CLEAR_DISPLAY);
displayInRow1(row1Text);
displayInRow2(row2Text);
CL_delayMS(2000);
while(count--)
{
sendLCDCommand(SHIFT_ENTIRE_LEFT);
CL_delayMS(scrollDelay);
}
}
void LCDDemoProgram(unsigned char *row1Data, unsigned char *row2Data)
{
initializeLCD();
sendTextToLCD (row1Data);
setRowAndColumnPositionOnDisplay (1,0);
sendTextToLCD (row2Data);
CL_delayMS(3000);
sendLCDCommand(CLEAR_DISPLAY);
// Just to demostrate how Hex values can be displayed without using itoa library function
displayOneByteHexValue(0,0,CLKPR);
setRowAndColumnPositionOnDisplay (1,0);
displayOneByteHexValue(1,12,0xE2);
CL_delayMS(3000);
sendLCDCommand(CLEAR_DISPLAY);
//Wait for 3 seconds
scrollingDisplayTest("Display will be cleared for 3 sec after displaying DONE ", "Please Wait.... Please Wait.....",1000);
CL_delayMS(2000);
sendLCDCommand(CLEAR_DISPLAY);
displayInRow1("DONE");
CL_delayMS(3000);
displayInRow1("Cur OFF Bl OFF");
sendLCDCommand(CURSOR_OFF_BLINK_OFF);
CL_delayMS(3000);
sendLCDCommand(CLEAR_DISPLAY);
displayInRow1("Cur OFF Bl ON");
sendLCDCommand(CURSOR_OFF_BLINK_ON);
CL_delayMS(3000);
sendLCDCommand(CLEAR_DISPLAY);
displayInRow1("Cur ON Bl OFF");
sendLCDCommand(CURSOR_ON_BLINK_OFF);
CL_delayMS(3000);
sendLCDCommand(CLEAR_DISPLAY);
displayInRow1("Cur ON Bl ON");
sendLCDCommand(CURSOR_ON_BLINK_ON);
CL_delayMS(3000);
displayNumberTest(100);
}
//////////////////////////////////////////////// Do No Use Below code. This is Only for demo purpose//////////////////////////////////////////
// Function to convert lower nibble to ASCII Value
//Only lower nibble of the input is considered and higher nibble is lost
// This function is written for understanding purpose only.
// itoa () library function can be used instead of this with base of 16.
unsigned char convertLowerNibbleToASCIIValue(unsigned char data)
{
data&=0x0F;
if(data<=9)
{
return(data+0x30);
}
else // There is no chance for getting more than 0x0F in the lowerNibble Parameter)
{
return(data+0x37);
}
}
// Function to convert Higher nibble to ASCII Value
//Only higher nibble of the input is considered and lower nibble is lost
unsigned char convertHigherNibbleToASCIIValue(unsigned char data)
{
data>>=4;
if(data<=9)
{
return(data+0x30);
}
else // There is no chance for getting more than 0x0F in the lowerNibble Parameter)
{
return(data+0x37);
}
}
void displayOneByteHexValue(unsigned char rowNum, unsigned char pos, char data)
{
char temp;
setRowAndColumnPositionOnDisplay(rowNum,pos);
temp = convertHigherNibbleToASCIIValue(data);
writeCharToLCD(temp);
temp = convertLowerNibbleToASCIIValue(data);
writeCharToLCD(temp);
}
// Displays 8 bit Register values in LCD display unit.
// name is the name of the register to be displayed. You can give any name.
// port is the register name.
void displayRegisterValues(unsigned char *displayName, volatile uint8_t *registerName)
{
char temp2;
displayInRow1(displayName);
//temp2=registerName;
temp2 = (convertLowerNibbleToASCIIValue(*registerName));
displayInRow1(&temp2);
// Get the higher Nibble
temp2 = (convertLowerNibbleToASCIIValue((*registerName)>>4));
displayInRow2(&temp2);
}
int main(void)
{
LCDDemoProgram("Hello", "World is Great");
while(1)
{
//TODO:: Please write your application code
}
return(0);
}

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