Problem with toggle led on Arduino nano Atmega328P with timer/counter0 interrupt - timer

I try to toggle the LED on Arduino nano ATmega328P without success.
(Timer 0 is 8bit timer)
I managed to execute it with Timer 1
with code from here.
#define ledPin 13
void setup() {
pinMode(ledPin, OUTPUT);
cli(); // disable interrupts
TCCR0A = 0;
TCCR0B = 0;
TCCR0B |= (1 << CS02 | 1 << CS00); //clkI/O/1024
TIMSK0 = 0;
TIMSK0 |= (1 << TOIE0); // Overflow Interrupt Enable
TCNT0 = 0;
sei(); // enable interrupts
Serial.begin(9600);
}
ISR(TIM0_OVF_vect) {
digitalWrite(ledPin, digitalRead(ledPin) ^ 1);
}
void loop() {
}
I also tried to change the interrupt vector to: TIMER0_OVF_vect
and got this error:
Arduino: 1.8.9 (Windows 10), Board: "Arduino Nano, ATmega328P (Old Bootloader)"
wiring.c.o (symbol from plugin): In function `__vector_16':
(.text+0x0): multiple definition of `__vector_16'
sketch\tests.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here
collect2.exe: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino Nano.
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
I expect the led to toggle.

Your first block of code with:
ISR(TIM0_OVF_vect) {
digitalWrite(ledPin, digitalRead(ledPin) ^ 1);
}
has the wrong ISR name. TIM0_OVF_vect is only valid for some ATtiny microcontrollers. You can find a complete list of interrupts and which controllers they are used with here.
You then tried to change it to use TIMER0_OVF_vect, which is valid for the ATMEGA328P, but you cannot use this with Arduino, because Arduino ATMEGA328P builds use Timer0 for millis() and related timing. This is why you get a multiple definition of error - the linker is telling you that there are two TIMER0_OVF_vect ISRs defined by your program (one by your sketch, one in wiring.c).
Timer2 is not used by default, so you should be able to use that instead. The only default Arduino library that used Timer2 is the Tone library.

Related

How to acheive Adafruit Feather M0 Sleep & Wake on External Interrupt using any Pin?

I am currently working on a low-power project using the Adafruit Feather M0 microprocessor. A requirement of my project is to be able to sleep the CPU and wake it again using an external interrupt triggered from the MPU6050 accelerometer.
I have tested the following code sample from GitHub - it works successfully! The question that I need answering is how to I alter this sample code to work on Pin 13 of the feather, rather than pin 6.
#define interruptPin 6
volatile bool SLEEP_FLAG;
void EIC_ISR(void) {
SLEEP_FLAG ^= true; // toggle SLEEP_FLAG by XORing it against true
//Serial.print("EIC_ISR SLEEP_FLAG = ");
//Serial.println(SLEEP_FLAG);
}
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(3000); // wait for console opening
attachInterrupt(digitalPinToInterrupt(interruptPin), EIC_ISR, CHANGE); // Attach interrupt to pin 6 with an ISR and when the pin state CHANGEs
SYSCTRL->XOSC32K.reg |= (SYSCTRL_XOSC32K_RUNSTDBY | SYSCTRL_XOSC32K_ONDEMAND); // set external 32k oscillator to run when idle or sleep mode is chosen
REG_GCLK_CLKCTRL |= GCLK_CLKCTRL_ID(GCM_EIC) | // generic clock multiplexer id for the external interrupt controller
GCLK_CLKCTRL_GEN_GCLK1 | // generic clock 1 which is xosc32k
GCLK_CLKCTRL_CLKEN; // enable it
while (GCLK->STATUS.bit.SYNCBUSY); // write protected, wait for sync
EIC->WAKEUP.reg |= EIC_WAKEUP_WAKEUPEN4; // Set External Interrupt Controller to use channel 4 (pin 6)
PM->SLEEP.reg |= PM_SLEEP_IDLE_CPU; // Enable Idle0 mode - sleep CPU clock only
//PM->SLEEP.reg |= PM_SLEEP_IDLE_AHB; // Idle1 - sleep CPU and AHB clocks
//PM->SLEEP.reg |= PM_SLEEP_IDLE_APB; // Idle2 - sleep CPU, AHB, and APB clocks
// It is either Idle mode or Standby mode, not both.
SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk; // Enable Standby or "deep sleep" mode
SLEEP_FLAG = false; // begin awake
// Built-in LED set to output and high
PORT->Group[g_APinDescription[LED_BUILTIN].ulPort].DIRSET.reg = (uint32_t)(1<<g_APinDescription[LED_BUILTIN].ulPin); // set pin direction to output
PORT->Group[g_APinDescription[LED_BUILTIN].ulPort].OUTSET.reg = (uint32_t)(1<<g_APinDescription[LED_BUILTIN].ulPin); // set pin mode to high
Serial.println("Setup() Run!");
}
void loop() {
// put your main code here, to run repeatedly:
if (SLEEP_FLAG == true) {
PORT->Group[g_APinDescription[LED_BUILTIN].ulPort].OUTCLR.reg = (uint32_t)(1<<g_APinDescription[LED_BUILTIN].ulPin); // set pin mode to low
Serial.println("I'm going to sleep now.");
__WFI(); // wake from interrupt
SLEEP_FLAG = false;
Serial.println("Ok, I'm awake");
Serial.println();
}
//Serial.print("SLEEP_FLAG = ");
//Serial.println(SLEEP_FLAG);
PORT->Group[g_APinDescription[LED_BUILTIN].ulPort].OUTTGL.reg = (uint32_t)(1<<g_APinDescription[LED_BUILTIN].ulPin); // toggle output of built-in LED pin
delay(1000);
}
As per the pinout diagram and Atmel datasheet, I am struggling to work out which changes to make to allow pin 13 to operate in the same way as pin 6.
Atmel Datasheet
The obvious solution is to change the following lines...
#define interruptPin 13
EIC->WAKEUP.reg |= EIC_WAKEUP_WAKEUPEN1; // Set External Interrupt Controller to use channel 4 (pin 6)
I suspected channel 1 (WAKEUPEN1) due to the ENINT^1 next to pin 13 on the pinout diagram. But this didn't work, the code pin operation did not exhibit the same behaviour as the pin 6 setup.
I would be very grateful for any suggestion of how to implement this code working on Pin 13. Many thanks for your support.
I'm not an authority here, and your code looks correct to me.
Except, the pin out shows Pin 13 is the built-in LED line, and you manipulate LED_BUILTIN several places in your code. That's almost certainly conflicting with your attempts to use 13 as an interrupt line.

Blinking Led in Bare-Metal C programming: STM32L476RG Nucleo Board

I tried to implement a classic blink example on an STM32L476RG Nucleo board.
According to the STM32L4x datasheet: the LD2 is connected to the GPIOA PORT 5 (PA5).
The PA5 uses the AHB2 bus.
Note: I used Keil uVision 5; I created a New uVision Project with STM32L476RGTx target.
In the "Manage Run-Time Environment" dialog box I selected:
CMSIS >> Core (flag)
Device >> Startup (flag)
Here the code:
#include "stm32l4xx.h" // Device header
//#include <stdint.h>
//#define MASK(x) ((uint32_t) (1<<(x))) // bitmasking
void delayMs(int delay);
int main(void){
// RCC->AHB2RSTR |=1;
// RCC->AHB2RSTR &=~1;
// RCC->AHB2ENR |= MASK(0); //bitwise OR. Enable GPIOA clock
RCC->AHB2ENR |= 1;
//GPIOA->MODER |= MASK(10);
GPIOA->MODER |= 0x400;
while(1){
//GPIOA->ODR |= MASK(4);
GPIOA->ODR |= 0x20;
delayMs(500);
//GPIOA->ODR &= ~MASK(4);
GPIOA->ODR &= ~0x20;
delayMs(500);
}
}
void delayMs(int delay){
int i;
for(;delay>0; delay --){
for (i=0; i<3195;i++);
}
}
The Build output returns:
Build started: Project: blinknew
*** Using Compiler 'V5.06 update 6 (build 750)', folder: 'C:\Keil_v5\ARM\ARMCC\Bin'
Build target 'Target 1'
compiling main.c...
linking...
Program Size: Code=520 RO-data=408 RW-data=0 ZI-data=1632
".\Objects\blinknew.axf" - 0 Error(s), 0 Warning(s).
Build Time Elapsed: 00:00:09
and when I download it, Keil uV 5 returns:
Load "C:\\Users\\gmezz\\OneDrive\\Documenti\\Bare_Metal\\Blinknew\\Objects\\blinknew.axf"
Erase Done.
Programming Done.
Verify OK.
Flash Load finished at 22:37:52
The LED should blink with a period of 1 s, but in reality, nothing happens.
Honestly, I don't understand what is going wrong.
Someone can help me?
GM
I may be wrong, but according to the reference manual (RM0351) section 6.2.19, you should wait 2 clock cycles after enabling the peripheral clock, before accessing its registers. Try introducing a short delay after RCC->AHB2ENR |= 1; line. In your case, I think MODER register is not getting the correct value.
I also suggest checking the actual values of registers with a debugger.

Unable to get the timer working

I have written simple timer program for Atmega328 in normal mode. But I am unable to flash the LED if I compile the code in Atmel Studio 6.2. But same code works perfect if I compile in arduino IDE. I have given the code for Arduino as well as Atmel Studio below. There seems to be small issue somewhere. Is there any issue with F_CPU value?
// Code compiled using Atmel Studio:
#include <avr/io.h>
#include <avr/interrupt.h>
#define F_CPU 16000000
unsigned char x=0;
ISR(TIMER1_OVF_vect) {
x=!x;
}
void setup() {
DDRB=0x01;
TIMSK1=0x01; // enabled global and timer overflow interrupt;
TCCR1A = 0x00; // normal operation page 148 (mode0);
TCNT1=0x0000; // 16bit counter register
TCCR1B = 0x04; // start timer/ set clock
};
int main (void)
{
setup();
while(1)
{
PORTB= x;
}
return(0);
}
Code written with Arduino IDE:
#define LED 8
boolean x=false;
ISR(TIMER1_OVF_vect) {
x=!x;
}
void setup() {
pinMode(LED, OUTPUT);
TIMSK1=0x01; // enabled global and timer overflow interrupt;
TCCR1A = 0x00; // normal operation page 148 (mode0);
TCNT1=0x0000; // 16bit counter register
TCCR1B = 0x04; // start timer/ set clock
};
void loop() {
PORTB= x;
}
When working with interrupts, you need to enable both the global interrupts (in the timer register) and the local interrupts (in the status registers) in order for interrupt vectors to trigger.
This can be done by calling sei() (set enable interrupts) when you are ready to receive local interrupts. Typically you want to do this after you set up the global interrupts, near the end of you setup method.
I suspect that the interrupts are automatically enabled when working with the Arduino IDE.

AVR - ATmega8A - External Interrupt - Sometimes odd behaviour

I am currently working on a MCU unit which will respond to external interrupts in order to perform specific tasks.
The controller I am using: ATmega8A.
The external interrupt is defined as followed:
PORTD |= 0x04; //Activate pull up resistor of PD2
GICR |= (1 << INT0); //Enable INT0
MCUCR |= (1<<ISC00); //INT0 is executed on every edge
The ISR:
ISR (INT0_vect)
{
/* interrupt code here */
v = 1; //sets interrupt variable v to 1
}
I am currently testing the behavior of the external interrupts. Whenever an external interrupt is detected a particular code block should be executed.
The interrupt is applied to the INT0 by any logic change.
ISR (INT0_vect)
{
/* interrupt code here */
v = 1; //sets interrupt variable v to 1
}
int main(void)
{
USART_Init();
I2C_init();
//int a; //test variable
PORTD |= 0x04; //Activate pull up resistor of PD2
GICR |= (1 << INT0); //Enable INT0
MCUCR |= (1<<ISC00); //INT0 is executed on every edge
sei();
unsigned char a;
a = USART_Receive();
while(1)
{
//TODO:: Please write your application code
do
{
} while (v == 0); //Wait for interrupt
v = 0;
_delay_ms(10000);
//Communication protocol between MCU unit and GUI software application
//Block 1
USART_Transmit(0xFF); //Header start command
USART_Transmit(0x00);
USART_Transmit(0x08);
USART_Transmit(0x00);
USART_Transmit(0x09);
USART_Transmit(0x02);
USART_Transmit(0x04);
USART_Transmit(0x05);
USART_Transmit(0x06);
USART_Transmit(0x00);
USART_Transmit(0xFE); //Header finish command
do
{
} while (v == 0); //Wait for interrupt
v = 0;
_delay_ms(10000);
//Block 2
USART_Transmit(0xFF); //Header start command
USART_Transmit(0x00);
USART_Transmit(0x01);
USART_Transmit(0x00);
USART_Transmit(0x01);
USART_Transmit(0x01);
USART_Transmit(0x01);
USART_Transmit(0x01);
USART_Transmit(0x01);
USART_Transmit(0x01);
USART_Transmit(0xFE); //Header finish command
}
return 0;
}
Testing the code, I can say that the interrupts are recognized and the code is functioning. However, it seems that there is a little bug or logic error.
When the first interrupt occurs (before block 1), block 1 is supposed to be executed. Now, if the second interrupt occurs, the 2nd block should be executed.
I can see this execution sequence in a pre-written GUI application, however, most of the time block 1 (when applying the interrupt) is executed many times after another and than block 2.
It should always be the following sequence: block 1 than block 2 and so on. I think that this is a timing issue. But I cannot debug this problem.
I am also wondering if there is a code in C that tells the program to wait for an external interrupt signal and than continues the program?
Thank you very much in advance.

AVR C how to stop interrupt

I am programming a AVR MCU.
It has a POT that reads off an analogue pin. It seems that the interrupt is constantly called, and it must be called during a LCD_display method as it is messing with my LCD.
Is there a way to STOP the inturrupts until after the block is run?
int main(void)
{
/*Turn on ADC Interrupt */
ADCSRA |= (1 << ADIE);
/*Turn On GLobal Interrupts*/
sei();
/* Intalise LCD */
lcd_init(LCD_DISP_ON); /* initialize display, cursor off */
lcd_clrscr();
lcd_puts("READY");
DDRB &= ~(1 << PINB5); //set input direction
ADC_Init(128, 0); //initalize ADC
while (1)
{
if (!bit_is_clear(PINB, 5))
{
_delay_ms(500);
if (!pressed)
{
lcd_gotoxy(0,0);
lcd_clrscr();
lcd_puts("test"); //Doesnt work unless I dont comment out the last line of interrupt
pressed = 1;
}
}
/* INTERRUPTS */
//ADC INTERRUPT
ISR(ADC_vect)
{
char adcResult[4];
uint8_t theLowADC = ADCL;
uint16_t theTenBitResults = ADCH<<8 | theLowADC;
itoa(theTenBitResults, adcResult, 10);
ADCSRA |= (1 << ADSC); //next conversion *if i comment out this line it works*
}
If the interrupt handler behaves bad with your code, the reason could be you spend too much time in the interrupt handler. You should only do critical work in the interrupt handler and defer the less critical work in the application code; use a volatile flag shared between the handler and the application code to let the application code know if it has work to do. In your example, you should defer the itoa call in the application code.
Use cli(); to disable interrupts and sei(); to enable them again after you finished the display routine.
Which MCU are you using? You should propably use a timer instead of a delay of 500ms.
I believe, I am little late but still I had the same issue I solved it using the following method,
Interrupts are enabled using two flags
1.A global interrupt flag
2.A module related interrupt flag (in your case ADC)
You can have control over module related flag, in your case in the ADCSRA control register there is a flag named ADIE- ADC Interrupt Enable flag you can use that to control the Interrupts.
For example,
In main function you can enable the flag and in ISR disable the flag.
main()
{
//enable global flag and ADC flag
while(1)
{
//your logic
// enable ADC flag
}
}
ISR()
{
//disable the ADC flag
}
I hope this solves the issue you are having.

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