Read a txt file from PC using UART - Atmega32A - c

I am a beginner in microprocessor programming. I created an array and sent datas using UART. I want to read a text file and create this array using datas in the text file with the simplest way possible. Any suggestion to proceed? Thanks in advance.
#include <avr/io.h>
#include <stdio.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#define F_CPU 8000000UL // Clock freq
char flag = 0;
void usart_init(void){
UCSRA = 0x02;
UCSRB = 0x98; // Enable transmitter Enable receiver Enable Interrupt
UCSRC = (1<<UCSZ1) | (1<<UCSZ0); // set as 8 bit data, no parity bit and 1 stop bit.
UBRRH = 0x00;
UBRRL = 109;
}
int main(void){
usart_init();
while(1){
unsigned char array[5]={0x44,0xAA,0x33,0xBB,0x55};
for (int i=0;i<5;i++){
UDR = array[i];
UDR = 0xFF;
_delay_ms(100);
}
sei();
if(flag == 1)
{
flag = 0;
UCSRB = 0x98;
}
}
}
ISR(USART_RXC_vect){
UCSRB = (0<<RXEN)|(0<<TXEN)|(0<<RXCIE);
flag = 1;
}

You are working with a microcontroller so you can't handle a file directly. You had to code every value (copy & paste) in your source code.
unsigned char const array[5]={0x44,0xAA,0x33,0xBB,0x55};
You had to do this even for a large array.

Related

uart between atmega328p (C) and Feather m0 (Arduino) receive

I want to send data from my ac/gy via atmega328p to a feather m0 module. The atmega is programmed in C using the following github code: https://github.com/YifanJiangPolyU/MPU6050
And the Arduino code for receiving data within the LoRa module is shown below:
void do_send(osjob_t* j){
// Check if there is not a current TX/RX job running
if (LMIC.opmode & OP_TXRXPEND) {
Serial.println(F("OP_TXRXPEND, not sending"));
} else {
// Prepare upstream data transmission at the next possible time.
byte strArray[30];
int i = 0;
if(Serial1.available()>0) {
while (Serial1.available()>0){
strArray[i] = Serial1.read();
i++;
}
// send the 6 bytes payload to LoRaWAN port 7 --> now port 1
LMIC_setTxData2(1, strArray, sizeof(strArray), 1);
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on by making the voltage HIGH //optional: for confirmation
}
}
}
// Next TX is scheduled after TX_COMPLETE event.
//delay(60000);
void loop() {
os_runloop_once();
}
However, I can't seem to receive anything and can't send a "char array" to the gateway using the LMIC function apparently, so trying to receiving data within a byte array instead. Any help or tips regarding this is greatly appreciated. I'll also include the main.c code for the atmega328P down here below:
#define F_CPU 16000000UL
#define BAUD 9600
#include <inttypes.h>
#include <avr/sfr_defs.h>
#include <stdint.h>
#include <avr/io.h>
#include <util/delay.h>
#include <util/setbaud.h>
#include <avr/interrupt.h>
#include <math.h>
#include "mpu6050.h"
#include "mpu6050_reg.h"
#include "i2c.h"
#include "uart.h"
void timer_setup();
void get_time(double* dt);
volatile double count;
const double unit_t = 8/16000000;
int main(void){
sei();
uart_init();
i2c_init();
DDRB |= _BV(5);
uint8_t ret;
int16_t accel_buff[3], gyro_buff[3];
double accelX, accelY, accelZ;
double gyroX, gyroY, gyroZ;
double biasX, biasY;
double phi_accel, theta_accel;
double phi_innov, theta_innov;
double phi_est, theta_est;
double phi_prev, theta_prev;
double dt;
char s[30];
// initialize & test MPU5060 availability
ret = i2c_start(MPU6050_ADDRESS+I2C_WRITE);
if(~ret){
PORTB |= _BV(5);
_delay_ms(200);
PORTB &= ~(_BV(5));
}
mpu6050_init();
timer_setup();
// find gyro bias
biasX = 0;
biasY = 0;
uint8_t i;
for(i=0; i<20; i++){
mpu6050_read_gyro_ALL(gyro_buff);
biasX += gyro_buff[0];
biasY += gyro_buff[1];
}
biasX = biasX/20*(3.14159/180)/1000/32768;
biasY = biasY/20*(3.14159/180)/1000/32768;
// initialization for Kalman filter
double P = 0.0;
double Q = 0.001;
double R = 0.03;
double Pp, K;
mpu6050_read_accel_ALL(accel_buff);
phi_prev = atan2(accelY, accelZ); // row
theta_prev = atan2(-accelX, sqrt(accelY*accelY+accelZ*accelZ)); // pitch
for(;;){
get_time(&dt);
mpu6050_read_accel_ALL(accel_buff);
mpu6050_read_gyro_ALL(gyro_buff);
// acceleration (m/s^2)
accelX = accel_buff[0]*9.8*2/32768;
accelY = accel_buff[1]*9.8*2/32768;
accelZ = accel_buff[2]*9.8*2/32768;
// gyro rate (rad/s)
gyroX = gyro_buff[0]*(3.14159/180)/1000/32768;
gyroY = gyro_buff[1]*(3.14159/180)/1000/32768;
gyroZ = gyro_buff[2]*(3.14159/180)/1000/32768;
// estimation
phi_est = phi_prev + dt*(gyroX - biasX);
theta_est = theta_prev + dt*(gyroY - biasY);
Pp = P+Q;
// innovation
phi_accel = atan2(accelY, accelZ); // row
phi_innov = phi_accel - phi_est;
theta_accel = atan2(-accelX, sqrt(accelY*accelY+accelZ*accelZ)); // pitch
theta_innov = theta_accel - theta_est;
// Kalman gain
K = Pp/(Pp+R);
// correction
phi_prev = phi_prev + K*phi_innov;
theta_prev = theta_prev + K*theta_innov;
P = (1-K)*Pp;
uart_putchar('\n');
_delay_ms(10);
uart_putdouble(phi_prev); //phi, row
uart_putdouble(theta_prev); //theta, pitch
uart_putdouble(dt);
//_delay_ms(10);
}
}//end of main
void timer_setup(){
TCCR1A = 0x00;
TIMSK1 |= _BV(TOIE1);
TCCR1B |= _BV(CS11);
TCCR1B &= ~( _BV(CS12) | _BV(CS10)); // prescaler=8
}
void get_time(double * dt){
cli();
uint8_t l = TCNT1L;
uint8_t h = TCNT1H;
uint16_t step = h<<8 | l;
*dt = (double)step*5e-7 + count*0.032768;
count = 0;
sei();
}
// timer 1 overflow interrupt handler
SIGNAL(TIMER1_OVF_vect){
count += 1;
}
Connect the board to the PC and check in the Arduino IDE Serial Monitor if you can get or send data.
If your serial communication doesn't work, you can check if you are past a point in execution by turning on the led on the board. Most development boards have at least 1, and with Arduino is just a matter of setting the pin as output and digitalWrite(LED_BUILTIN, 0) in setup, then digitalWrite(LED_BUILTIN, 1) at the point you want to check.
If your atmega328p is on an arduino board (e.g. uno, nano etc) you should check in the same way for it, too. Both the serial and past-the-point verification.
I'd to that, then rely on the serial for debugging for a while.
I'm curious, do you think the condition "if(Serial1.available()>0)" is true?

How do i fetch data from UDRn on Mega2560?

Noob question:
I'm trying to learn about UART on an ARDUINO. I wrote some very simple code and for some reason, i can't make the receive() function work. I don't think it fetches the data from the UDR register. I'm using a small OLED display and i want to print the received data to it. No data is being printed to the display, when i run the code.
I connected the ports TX1 and RX1 with a wire on the board.
I tried finding youtube videos and have been reading alot. Appearently not enough.
Any ARDUINO expert who knows what to do?
#include <avr/io.h>
#include "ssd1306.h"
#include "I2C.h"
#include <stdio.h>
#include <util/delay.h>
void initOLED();
void initUART1();
void receive();
void transmit();
int main(void)
{
I2C_Init();
initOLED(); //initialiaze OLED
while (1)
{
transmit();
receive();
}
}
void initOLED()
{
I2C_Init();
InitializeDisplay();
clear_display();
}
void initUART1(void)
{
DDRD = 0x08; //TXD1 set to output
UBRR1L = 51; //Baudrate 19200
UBRR1H = 0; //upper four bits of baudrate
UCSR1A = 0x02; //Double speed mode
UCSR1B = 0x18; //Enable receive and transmit
UCSR1C = 0x06; //1 stop bit, 8-bit, no parity
}
void transmit()
{
char b = 'a';
while(!(UCSR1A & (1<<UDRE1))); //wait for an empty UDR register
UDR1 = b; //load character in register
}
void receive()
{
int Y = 0; //Y coordinate for cursor on the display
char d;
while(!(UCSR1A & (1<<RXC1))); //wait for unread data in the receive buffer
d = UDR1; //set UDR register in character d
sendCharXY(d, 1, Y); //send character to display
}
It looks like you never call initUART1().

AVR, UART, Proteus simulation, not all data displayed on virtual terminal

I am writing a code for a MCU until that will transmit data via UART (RS232).
[ATmega8A]
Currently, I am testing my code in Proteus:
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdlib.h>
#include <compat/twi.h>
#define FOSC 16000000 //Clock Speed
#define BAUD 9600 //Baud rate set to 9600
#define MYBRR FOSC/16/BAUD-1
void USART_Init (void)
{
UBRRH = (MYBRR >> 8); //Code for setting
UBRRL = MYBRR; //the baud rate
UCSRB = (1 << RXEN) | (1 << TXEN); //Enable receiver and transmitter
UCSRC = (1 << URSEL) | (1 << UCSZ0) | (1 << UCSZ1); //Frame format setting: 8 Data, 2 Stop bit
}
/* USART transmit function */
void USART_Transmit(unsigned char data)
{
while(!(UCSRA & (1 << UDRE))); //Wait until transmit buffer is empty
UDR = data;
}
/* USART receive function */
unsigned char USART_Receive(void)
{
while(!(UCSRA & (1 << RXC))); //Wait until data is received
return UDR; //Get the data from buffer and return it
}
and the test code in main:
int main(void)
{
unsigned char c;
while(1)
{
a = USART_Receive();
c = 10;
USART_Transmit(c);
_delay(10000);
}
}
In Proteus, the virtual terminal displays 0. However, I am expecting to see 10.
This is just one example, in general only the last digit/character is getting displayed on the virtual terminal.
I cannot explain this. Proteus bug or logic error?
Thank you for any advise.
UART data is sent only in ascii format...you have to convert the integer data to ascii format..use itoa() or do this one
int main(void)
{
unsigned char c;
unsigned char b;
while(1)
{
a = USART_Receive();
c = 10;
b=c;
b=c/10;
USART_Transmit(b+48);
b=0;
b=c%10;
USART_Transmit(b+48);
_delay(10000);
}
}

Where have the missing letters gone?

Only 4 letters are showing up. Like in the example, I send the string "abcdef", but it only shows the 4 letters "abcf". I don't know why the other letters don't show up. I'm using Atmega8 and Bray terminal. I'm already following from the datasheet [http://ww1.microchip.com/downloads/en/DeviceDoc/21822E.pdf][1]. But I've already found a dead end.
Implementation of functions
#include <avr/io.h>
#include <math.h>
#include <util/delay.h>
#define DD_SS PINB2 //Chip select ON RC2
#define DD_MOSI PINB3 // Master out - Slave in pin
#define DD_MISO PINB4 // Master in - Slave out pin
#define DD_SCK PINB5 // Clock from master
#define DDR_SPI PORTB // DDR_SPI
void serial_init(void)
{
UBRRH = 0x00;
UBRRL = 7;
UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0)|(1 << UCSZ1);
UCSRB = (1 << RXEN) | (1 << TXEN)| (1<<RXCIE);
}
unsigned char Usart_Receive(void)
{
while ((UCSRA & (1 << RXC)) == 0) {};
return UDR;
}
void Usart_Transmit(unsigned char c)
{
PORTD= 0b00000100; //RTS Enable
while ((UCSRA & (1 << UDRE)) == 0) {};
UDR = c;
PORTD= 0b00000000; //RTS Disable
}
void SPI_MasterInit(void)
{
DDRB = 0b00101100;
DDR_SPI = (1<<DD_MOSI)|(1<<DD_SCK);
SPCR = 0b01010000;
SPSR = 0b00000001;
}
unsigned char spi_transfer(volatile char data)
{
SPDR = data;
while(!(SPSR & (1<<SPIF)));
{
}
return SPDR;
}
void SPI_MasterTransmit (uint8_t Data)
{
uint16_t address;
SPCR = (1<<SPE) | (1<<MSTR) | (0<<CPHA);
DDR_SPI &= ~(1<<DD_SS); // Select EEPROM
spi_transfer(WREN); // Send WRITE_ENABLE command
DDR_SPI |= (1<<DD_SS); // Release EEPROM
DDR_SPI &= ~(1<<DD_SS); //ss goes low
spi_transfer(WRITE); // write data to memory
spi_transfer (address>>8);
spi_transfer (address);
spi_transfer(Data);
DDR_SPI |= (1<<DD_SS); //ss goes high
}
unsigned char SPI_MasterReceive(uint16_t address)
{
unsigned long data;
SPCR = (1<<SPE) | (1<<MSTR) | (0<<CPHA);
//waitBusy();
DDR_SPI &= ~(1<<DD_SS); //ss goes low
spi_transfer(READ); //enable write operation
spi_transfer (address>>8);
spi_transfer (address);
data = spi_transfer(0xff);
DDR_SPI |= (1<<DD_SS); //goes high
return data;
}
and this is main function
int main (void)
{
char data;
unsigned char address;
serial_init();
SPI_MasterInit();
while(1)
{
data = Usart_Receive();
_delay_ms(10);
SPI_MasterTransmit(data);
_delay_ms(10);
data = SPI_MasterReceive(address); //read data from the memory
_delay_ms(10); //pause for readability
Usart_Transmit(data);
}
return 0;
}
I hope someone can help me here. :)
Your USART is transmitting too fast for your receiver. By your fourth time through the main loop, the USART transmitter has overwritten the "d" with "e" and then with "f".
A way to get around this is to use interrupts for receiving data, instead of polling like you are doing now. But you won't be able to write to the EEPROM as fast as the interrupts come. Instead, you should queue up the letters into a circular array or linked list or some other data structure as they arrive, and then write them to EEPROM in the main loop as time allows.
Note that this solution will only help with bursty data; you save up the burst and then deal with it as you can. But if the USART is continuously too fast, then you will never be able to keep up.
To debug this issue you need to localise the place of problem and to do this you have to split your experiment on sub-tasks.
One of them is to check UART separately, the code gets here like:
while(1)
{
data = Usart_Receive();
_delay_ms(10);
Usart_Transmit(data);
}
The second one is to check SPI apart from UART stuff if you have JTAG, or altogether if you get managed with making UART working. For the separate SPI checking just comment Usart_Receive(); and Usart_Transmit(data); initialize data with anything and probably increment it in the while. Hope this idea helps.

LCD shift right and shift left bugs

I have made a library for LCD with HD44780 controller in it, and from the datasheet I read that the code 0x18 will shift the entire display one position to the left, but when I made that, the display disappears.
I have also read that 0x1C shifts the entire display one position to the right but when I made it, the entire display shifts to left.
My code:
/*
* main.c
*
* Created: 11/14/2013 7:54:02 PM
* Author: A R M T
*/
#include <avr/io.h>
#define F_CPU 1000000UL
#define __DELAY_BACKWARD_COMPATIBLE__
#include <util/delay.h>
#define LCD_DPRT PORTA //LCD DATA PORT
#define LCD_DDDR DDRA //LCD DATA DDR
#define LCD_DPIN PINA //LCD DATA PIN
#define LCD_CPRT PORTB //LCD COMMANDS PORT
#define LCD_CDDR DDRB //LCD COMMANDS DDR
#define LCD_CPIN PINB //LCD COMMANDS PIN
#define LCD_RS 0 //LCD RS
#define LCD_RW 1 //LCD RW
#define LCD_EN 2 //LCD EN
//*************************************************************
void delay_us(unsigned int d);
void lcdCommand(unsigned char cmnd);
void lcdData(unsigned char data);
void lcd_init(void);
void lcd_gotoxy(unsigned char x, unsigned char y);
void lcd_print(char *str);
//*************************************************************
void delay_us(unsigned int d)
{
_delay_us(d);
}
//*************************************************************
void lcdCommand(unsigned char cmnd)
{
LCD_DPRT = cmnd; //send cmnd to data port
LCD_CPRT &= ~(1<<LCD_RS); //RS = 0 for command
LCD_CPRT &= ~(1<<LCD_RW); //RW = 0 for write
LCD_CPRT |= (1<<LCD_EN); //EN = 1 for H-to-l pulse
delay_us(1); //Wait to make enable wide
LCD_CPRT &= ~(1<<LCD_EN); //EN = 1 for H-to-l pulse
delay_us(100); //Wait to make enable wide
}
//*************************************************************
void lcdData(unsigned char data)
{
LCD_DPRT = data; //send data to data port
LCD_CPRT |= (1<<LCD_RS); //RS = 1 for data
LCD_CPRT &= ~(1<<LCD_RW); //RW = 0 for write
LCD_CPRT |= (1<<LCD_EN); //EN = 1 for H-to-L pulse
delay_us(1); //wait to make enable wide
LCD_CPRT &= ~(1<<LCD_EN); //EN = 0 for H-to-L pulse
delay_us(100); //wait to make enable wide
}
//*************************************************************
void lcd_init(void)
{
LCD_DDDR = 0xFF;
LCD_CDDR = 0xFF;
LCD_CPRT &= ~(1<<LCD_EN); //LCD_EN = 0
delay_us(15000); //wait for init
lcdCommand(0x38); //init. LCD 2 line, 5 * 7 matrix
lcdCommand(0x0E); //display on, cursor on
lcdCommand(0x01); //clear LCD
delay_us(2000); //wait
lcdCommand(0x06); //shift cursor right
}
//*************************************************************
void lcd_gotoxy(unsigned char x, unsigned char y)
{
unsigned char firstCharAdr[] = {0x80, 0xC0, 0x94, 0xD4};
lcdCommand(firstCharAdr[y-1] + x - 1);
delay_us(100);
}
//*************************************************************
void lcd_print(char *str)
{
unsigned char i = 0;
while (str[i] != 0)
{
lcdData(str[i]);
i++;
}
}
//*************************************************************
int main(void)
{
lcd_init();
lcd_gotoxy(1,1);
lcd_print("Armia");
lcd_gotoxy(1,2);
lcd_print("Wagdy");
_delay_ms(1000 / 2);
lcdCommand(0x18); // Shift the entire display one position to the left
while(1);
return 0;
}
I meant that when I burned this code I excepected that aftr(1000 / 2) ms this output will shift to left
but what appears was(the word disappears instead of shifting left one postition)
Can any one help me in that problem please?!
I tried your code in proteus version 7.10 and shift left works fine
Note that you are using the _delay_us function with a variable parameter, that is not the correct way, it gives wrong delays and generates big hex file because it forces the float library to be included
delay.h manual
Note:
In order for these functions to work as intended, compiler optimizations must be enabled, and the delay time must be an
expression that is a known constant at compile-time. If these
requirements are not met, the resulting delay will be much longer (and
basically unpredictable), and applications that otherwise do not use
floating-point calculations will experience severe code bloat by the
floating-point library routines linked into the application.
Replace the code with a loop that calls the delay several times
while (d--)
{
_delay_ms(1);
}

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