/*
RC_Car_AVR.c
Created: 4/18/2018 7:55:07 PM
Author :
*/
#define F_CPU 16000000
#define BAUD 9600
#define TUBRR (((F_CPU / 16) / BAUD) - 1)
#include <avr/io.h>
#include <util/delay.h>
char Read;
void USART_Init(void){
UBRRL = TUBRR;
UCSRB = (1<<TXEN)|(1<<RXEN);
UCSRC = (1<<UCSZ1)|(1<<UCSZ0);
}
char USART_Receive(void){
/* Wait for data to be received */
while (!(UCSRA & (1<<RXC)));
/* Get and return received data from buffer */
return UDR;
}
int main(void){
USART_Init();
DDRB |= (1<<0);
PORTB |= (1<<0);
while (1){
Read = USART_Receive();
if(Read == 'F'){
PORTB ^= (1<<0);
_delay_ms(100);
}
}
}
I'm trying to toggle an LED when I receive a certain character through the Bluetooth module (HC05).
I've written the USART library just like the datasheet but it doesn't seem to work (I'm only concerned with the initialization and receiving code since I'm working on a half duplex system so i don't need the transmition part).
I'm using Atmega32a with a 16MHz external crystal Oscillator.
Please tell me if you find anything wrong.
Thanks in advance.
Your Initialization is wrong.
Try this
void USART_Init(void){
UBRRL = TUBRR;
UBRRH = TUBRR >> 8;
UCSRB = (1<<TXEN)|(1<<RXEN);
UCSRC = (1<<UCSZ1)|(3<<UCSZ0);
}
This is the following initialization code provided in data sheet of atmega32
void USART_Init( unsigned int baud )
{
/* Set baud rate */
UBRRH = (unsigned char)(baud>>8);
UBRRL = (unsigned char)baud;
/* Enable receiver and transmitter */
UCSRB = (1<<RXEN)|(1<<TXEN);
/* Set frame format: 8data, 2stop bit */
UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
}
I know following datasheet is little overhead in beginning But eventually you will see all your answers are provided there.
Related
I’m trying to interface atmega328p with Blutooth HC-0.
I was following the example in Atmega328P datasheet in USART section.
The code is simply trying to send a letter 'b' to Bluetooth terminal on mobile phone and receive a letter. If the received letter is 'a', an LED on PORTB0 will turn on, if the letter is 'c', the LED will turn off. But unfortunately nothing is working.
Connection between atmega328P and HC-05 is as follows:
HC-05 -> Atmega328P
RXD -> pin3
TXD -> pin2
GND -> pin8
VCC -> pin7
Bluetooth light is turning on and off, and is connected successfully to mobile phone but no data is received, and when the letters 'a' and 'c' are sent nothing happens with LED connected to PORTB0.
The code is shown here. Thank you for any help!
#define F_CPU 16000000UL // Clock Speed
#define BAUD 9600
#define MYUBRR F_CPU/16/BAUD-1
#include <stdint.h>
#include <avr/io.h>
#include <util/delay.h>
char data;
char data2 = 'b';
void USART_Init(unsigned int ubrr)
{
/* Set baud rate */
UBRR0H = (unsigned char)(ubrr>>8);
UBRR0L = (unsigned char)(ubrr);
/* Enable receiver and transmitter */
UCSR0B = (1<<RXEN0)|(1<<TXEN0);
/* Set frame format: 8data, 2stop bit */
UCSR0C = (1<<USBS0)|(3<<UCSZ00);
}
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_Transmit(char data)
{
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) );
/* Put data into buffer, sends the data */
UDR0 = data;
}
int main(void)
{
DDRB = 0b00000001;
PORTB = 0b00000000;
USART_Init(MYUBRR);
while (1) {
data = USART_Receive();
USART_Transmit(data2);
if (data == 'a') {
PORTB = 0b00000001;
} else if (data == 'c') {
PORTB = 0b00000000;
}
}
}
I can't initialize a QAPASS 1602A LCD with a PIC18F4620, I always get square blocks on both lines. In the beginning, I thought the LCD was broken so I got a new one but the outcome is the same. I use a logifind PIC 40 Mini development board connected to PC through a PICkit3, everything else is working fine on every port but not the LCD.
Thanks a lot for your help.
//main.c
#include "newxc8_header.h"
#include <xc.h>
#include "lcd_16x2.h"
void main(void) {
ADCON1=0x0F; //configuring all analog ports to digital
TRISB=0x00; //Set RBs as output
TRISD=0x00; //Set RDs as output
TRISE=0x00; //Set REs as output
LCD_Init(); //Initialize 16x2 LCD
LCD_String("Hello");
while(1);
}
//lcd_16x2.c
#include "lcd_16x2.h"
void LCD_Init(void)
{
__delay_ms(1000);
EN = 0;
RS = 0;
ldata = 0x00;
LCD_Command(0x38); // Initialization of 16X2 LCD: 8-bit, 2 Lines, 5x7 Dots
LCD_Command(0x0C); // Display ON Cursor OFF
LCD_Command(0x01); //clear LCD
LCD_Command(0x02); //cursor beginning first line
}
void LCD_Command(unsigned char cmd)
{
ldata = cmd; /* Send data to PORT as a command for LCD */
RS = 0; /* Command Register is selected */
EN = 1; /* High-to-Low pulse on Enable pin to latch data */
__delay_ms(5);
EN = 0;
__delay_ms(3);
}
void LCD_Char(unsigned char data)
{
ldata = data; /* Send data to LCD */
RS = 1; // Data Register is selected */
EN = 1; // High-to-Low pulse on Enable pin to latch data */
__delay_ms(5);
EN = 0;
__delay_ms(3);
}
void LCD_String(const char *msg)
{
while(*msg != 0)
{
LCD_Char(*msg);
msg++;
}
}
//lcd_16x2.h
#ifndef LCD_16X2_H
#define LCD_16X2_H
#ifdef __cplusplus
extern "C" {
#endif
#include <xc.h>
#define _XTAL_FREQ 16000000 //16 MHz (4 MHz x 4 PLL)
#define ldata LATB /*PORTB(RB0-RB7) is used for transmitting data to LCD*/
#define RS LATEbits.LATE0 /*RE0 pin is used for Register Select*/
#define EN LATEbits.LATE1 /*RE1 pin is used for Enable*/
void LCD_Init(void);
void LCD_Command(unsigned char );
void LCD_Char(unsigned char x);
void LCD_String(const char *);
void LCD_Clear();
#ifdef __cplusplus
}
#endif
#endif /* NEWFILE_H */
Your question does not contain enough details for a definitive answer.
The best guess is that you have a wiring error between your LogiFind PIC-40-MINI board:
and your QAPASS 1602A LCD module:
A photograph of how they are connected would be helpful.
If you are convinced the wiring is correct then a problem may be in the LCD_Init() function, see HD44780 data sheet page 45 for a flowchart about initializing the module in 8-bit parallel mode or in the code you have not posted.
Added on January 19, 2020:
I assembled a PIC18F4620 and LCD module as you described.
Found that your code as posted does not show the configuration words you are using.
When using the internal oscillator at the default frequency (1MHz) your code runs but it's 16 times slower than expected.
After adjusting some settings this is the final version of code:
//main.c
// PIC18F4620 Configuration Bit Settings
// 'C' source line config statements
// CONFIG1H
#pragma config OSC = INTIO67 // Oscillator Selection bits (Internal oscillator block, port function on RA6 and RA7)
#pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)
#pragma config IESO = OFF // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)
// CONFIG2L
#pragma config PWRT = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF // Brown-out Reset Enable bits (Brown-out Reset disabled in hardware and software)
#pragma config BORV = 3 // Brown Out Reset Voltage bits (Minimum setting)
// CONFIG2H
#pragma config WDT = OFF // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))
#pragma config WDTPS = 32768 // Watchdog Timer Postscale Select bits (1:32768)
// CONFIG3H
#pragma config CCP2MX = PORTC // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)
#pragma config PBADEN = OFF // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset)
#pragma config LPT1OSC = OFF // Low-Power Timer1 Oscillator Enable bit (Timer1 configured for higher power operation)
#pragma config MCLRE = ON // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled)
// CONFIG4L
#pragma config STVREN = ON // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config LVP = OFF // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)
#pragma config XINST = OFF // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))
// CONFIG5L
#pragma config CP0 = OFF // Code Protection bit (Block 0 (000800-003FFFh) not code-protected)
#pragma config CP1 = OFF // Code Protection bit (Block 1 (004000-007FFFh) not code-protected)
#pragma config CP2 = OFF // Code Protection bit (Block 2 (008000-00BFFFh) not code-protected)
#pragma config CP3 = OFF // Code Protection bit (Block 3 (00C000-00FFFFh) not code-protected)
// CONFIG5H
#pragma config CPB = OFF // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)
#pragma config CPD = OFF // Data EEPROM Code Protection bit (Data EEPROM not code-protected)
// CONFIG6L
#pragma config WRT0 = OFF // Write Protection bit (Block 0 (000800-003FFFh) not write-protected)
#pragma config WRT1 = OFF // Write Protection bit (Block 1 (004000-007FFFh) not write-protected)
#pragma config WRT2 = OFF // Write Protection bit (Block 2 (008000-00BFFFh) not write-protected)
#pragma config WRT3 = OFF // Write Protection bit (Block 3 (00C000-00FFFFh) not write-protected)
// CONFIG6H
#pragma config WRTC = OFF // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)
#pragma config WRTB = OFF // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)
#pragma config WRTD = OFF // Data EEPROM Write Protection bit (Data EEPROM not write-protected)
// CONFIG7L
#pragma config EBTR0 = OFF // Table Read Protection bit (Block 0 (000800-003FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR1 = OFF // Table Read Protection bit (Block 1 (004000-007FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR2 = OFF // Table Read Protection bit (Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks)
#pragma config EBTR3 = OFF // Table Read Protection bit (Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks)
// CONFIG7H
#pragma config EBTRB = OFF // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)
#include <xc.h>
#include "lcd_16x2.h"
void main(void) {
OSCCON = 0b01100000; // sets clock = 4MHz
OSCTUNE = 0b01000000; // turn on 4xPLL
ADCON1=0x0F; //configuring all analog ports to digital
TRISB=0x00; //Set RBs as output
TRISD=0x00; //Set RDs as output
TRISE=0x00; //Set REs as output
LCD_Init(); //Initialize 16x2 LCD
LCD_Command(0x80);
LCD_String("Hello");
LCD_Command(0xC0);
LCD_String(__TIME__ " v1 ");
while(1);
}
//lcd_16x2.c
#include <xc.h>
#include "lcd_16x2.h"
void LCD_Init(void)
{
__delay_ms(1000);
EN = 0;
RS = 0;
LCD_Command(0x38); // Initialization of 16X2 LCD: 8-bit, 2 Lines, 5x7 Dots
LCD_Command(0x0C); // Display ON Cursor OFF
LCD_Command(0x01); //clear LCD
LCD_Command(0x02); //cursor beginning first line
}
void LCD_Command(unsigned char cmd)
{
ldata = cmd; /* Send data to PORT as a command for LCD */
RS = 0; /* Command Register is selected */
EN = 1; /* High-to-Low pulse on Enable pin to latch data */
__delay_us(1);
EN = 0;
__delay_ms(4);
}
void LCD_Char(unsigned char data)
{
ldata = data; /* Send data to LCD */
RS = 1; // Data Register is selected */
EN = 1; // High-to-Low pulse on Enable pin to latch data */
__delay_us(1);
EN = 0;
__delay_us(50);
}
void LCD_String(const char *msg)
{
while(*msg != 0)
{
LCD_Char(*msg);
msg++;
}
}
//lcd_16x2.h
#ifndef LCD_16X2_H
#define LCD_16X2_H
#ifdef __cplusplus
extern "C" {
#endif
#include <xc.h>
#define _XTAL_FREQ 16000000 //16 MHz (4 MHz x 4 PLL)
#define ldata LATB /*PORTB(RB0-RB7) is used for transmitting data to LCD*/
#define RS LATEbits.LATE0 /*RE0 pin is used for Register Select*/
#define EN LATEbits.LATE1 /*RE1 pin is used for Enable*/
void LCD_Init(void);
void LCD_Command(unsigned char );
void LCD_Char(unsigned char x);
void LCD_String(const char *);
void LCD_Clear();
#ifdef __cplusplus
}
#endif
#endif /* NEWFILE_H */
I have this project that my boss asked me to do and the first step is to figure out how to set a given I2C register to high or low using the silicon lab library, if anyone knows any good sources for this type of problem please provide them thank you. The pic that I am using is the pic16f1823, I've already looked at the documentation of the pic but into only states how to read and write to an I2c.
I use this as a header file and seems to work well for PIC16F1827 which is basically the same as the 1823. It used the peripheral of the PIC. Just include in in any c file you want to use i2c in. Make sure you #define FOSC in order to calculate the correct baud rate. Also double check the port and tris assignments are correct for your device and make adjustments.
It uses polling instead of an interrupt. Uncomment the interrupt setup code and write an interrupt service routine to catch the interrupts.
#ifndef I2C_H
#define I2C_H
#ifdef __cplusplus
extern "C" {
#endif
/*
* Hi-Tech C I2C library for 12F1822
* Master mode routines for I2C MSSP port to read and write to slave device
* Copyright (C)2011 HobbyTronics.co.uk 2011
* Freely distributable.
*/
#define I2C_WRITE 0
#define I2C_READ 1
// Initialise MSSP port. (12F1822 - other devices may differ)
void i2c_Init(void){
// Initialise I2C MSSP
// Master 100KHz
TRISB2 = 1;
TRISB5 = 1;
SSP1CON1 = 0b00101000; // I2C Master mode
SSP1CON2 = 0b00000000;
SSP1CON3 = 0b00000000;
//SSP1MSK = 0b00000000;
SSP1ADD = I2C_BRG; // clock = FOSC/(4 * (SSPxADD+1))
//SSP1IE = 1; // enable interrupt
SSP1STAT = 0b10000000;
}
// i2c_Wait - wait for I2C transfer to finish
void i2c_Wait(void){
while ( ( SSP1CON2 & 0x1F ) || ( SSPSTAT & 0x04 ) );
}
// i2c_Start - Start I2C communication
void i2c_Start(void)
{
i2c_Wait();
SSP1CON2bits.SEN=1;
}
// i2c_Restart - Re-Start I2C communication
void i2c_Restart(void){
i2c_Wait();
SSP1CON2bits.RSEN=1;
}
// i2c_Stop - Stop I2C communication
void i2c_Stop(void)
{
i2c_Wait();
SSP1CON2bits.PEN=1;
}
// i2c_Write - Sends one byte of data
void i2c_Write(unsigned char data)
{
i2c_Wait();
SSPBUF = data;
}
// i2c_Address - Sends Slave Address and Read/Write mode
// mode is either I2C_WRITE or I2C_READ
void i2c_Address(unsigned char address, unsigned char mode)
{
unsigned char l_address;
l_address=address<<1;
l_address+=mode;
i2c_Wait();
SSPBUF = l_address;
}
// i2c_Read - Reads a byte from Slave device
unsigned char i2c_Read(unsigned char ack)
{
// Read data from slave
// ack should be 1 if there is going to be more data read
// ack should be 0 if this is the last byte of data read
unsigned char i2cReadData;
i2c_Wait();
SSP1CON2bits.RCEN=1;
i2c_Wait();
i2cReadData = SSPBUF;
i2c_Wait();
if ( ack ) SSP1CON2bits.ACKDT=0; // Ack
else SSP1CON2bits.ACKDT=1; // NAck
SSP1CON2bits.ACKEN=1; // send acknowledge sequence
return( i2cReadData );
}
#ifdef __cplusplus
}
#endif
#endif /* I2C_H */
Then you can use the higher level functions defined above to control a device, which is described in the datasheet of the slave device.
For example, to read from an eeprom:
#include <xc.h>
#define FOSC 16000000
#include "i2c.h"
unsigned char i2c_read_eeprom( unsigned char slaveaddress, unsigned char memaddress )
{
unsigned char data;
data = 123;
i2c_Start();
i2c_Address( slaveaddress, I2C_WRITE);
i2c_Write(memaddress);
if( SSP1CON2bits.ACKSTAT )
txstring("ACK!\r\n");
else txstring("nACK!\r\n");
i2c_Start();
i2c_Address( slaveaddress, I2C_READ);
data = i2c_Read(0);
i2c_Stop();
return data;
}
i need your help
i am trying atmega128a using AVR studio 7
but one problem is there
when i control DDRB and PORTB into main()
it works fine
but if i control DDRB and PORTB out of main()
if becomes error
'expected identifier or '(' before volatile'
i just want to know that why always handing DDRB and PORTB is only in main()
here is my code
#define F_CPU 14745600UL
#include <avr/io.h>
#include <util/delay.h>
DDRB = 0xFF;
PORTB = 0x00;
int main(void)
{
/* Replace with your application code */
PORTB = 0x01;
_delay_ms(300);
while (1)
{
PORTB <<= 1;
_delay_ms(300);
if(PORTB == 0x80){
PORTB = 0x01;
_delay_ms(300);
}
}
}
C is not a scripting language. Any line of code that actually runs must be inside a function. You can make a new function and call it from main.
They need to be assigned inside of a function because they are macros that end up getting replaced with something that looks like this:
(*(volatile uint8_t *)<address>)
where <address> is a memory address that corresponds to the register that you are trying to access. You are trying to cast and dereference a pointer, which is not a valid operation outside of a function.
I am writing a tiny OS as part of an assigment for school,but I got stuck when it comes to get keyboard input (press a key -> display it on screen). I am using the Bare Bones tutorial from osdev.org (gcc cross-compiler, GRUB bootloader, ld linker) and since I am in protected mode I can not use BIOS interrupts for input, that's why I have to write my own interrupt handler (?) but I'm not sure how to do that even after I read some osdev articles and forum discussions. Very similar problem (http://forum.osdev.org/viewtopic.php?f=1&t=9746) except that I don't know how to "set up the interrupts".
#if !defined(__cplusplus)
#include <stdbool.h> /* C doesn't have booleans by default. */
#endif
#include <stddef.h>
#include <stdint.h>
#define INT_DISABLE 0
#define INT_ENABLE 0x200
#define PIC1 0x20
#define PIC2 0xA0
#define ICW1 0x11
#define ICW4 0x01
void outb( unsigned short port, unsigned char val )
{
asm volatile("outb %0, %1" : : "a"(val), "Nd"(port) );
}
static __inline unsigned char inb (unsigned short int port)
{
unsigned char _v;
__asm__ __volatile__ ("inb %w1,%0":"=a" (_v):"Nd" (port));
return _v;
}
void init_pics(int pic1, int pic2)
{
/* send ICW1 */
outb(PIC1, ICW1);
outb(PIC2, ICW1);
/* send ICW2 */
outb(PIC1 + 1, pic1);
outb(PIC2 + 1, pic2);
/* send ICW3 */
outb(PIC1 + 1, 4);
outb(PIC2 + 1, 2);
/* send ICW4 */
outb(PIC1 + 1, ICW4);
outb(PIC2 + 1, ICW4);
/* disable all IRQs */
outb(PIC1 + 1, 0xFF);
}
/*irrelevant code*/
#if defined(__cplusplus)
extern "C" /* Use C linkage for kernel_main. */
#endif
void kernel_main()
{
terminal_initialize();
char c;
init_pics(0x20, 0x28);
c = inb(0x60);
terminal_putchar(c);
}
This is printing me a white box.If I try listening to port 0x64 I get some different character. I don't expect this to work, because I don't have the interrupt. I think it should be something like
void _interrupt button_pressed()
{
/*code*/
}
if(button_pressed)
{
c = inb(0x60);
//code to translate the char to ASCII
terminal_putchar(asciiChar);
}
Any help is appreciated. Thanks
If there is someone interested how I solved the problem, here is the solution
char c = 0;
init_pics(0x20, 0x28);
do
{
if(inb(0x60)!=c) //PORT FROM WHICH WE READ
{
c = inb(0x60);
if(c>0)
{
terminal_putinput(c); //print on screen
}
}
}
while(c!=1); // 1= ESCAPE
c variable contains the code of the pressed button. Creating a translation array by associating to each code, the corresponding ASCII code, I can print the letter/number which is written on button.
The buttons code can be found here: http://www.nondot.org/sabre/os/files/HCI/keyboard.txt
The ASCII here: http://www.ascii-code.com/