A mechanism for the control of program flow in a computer. When interrupted a computer saves it's present operational state and changes to execution of code that is dependant upon which interrupt was generated. Interrupts can be either Hardware sourced or software sourced. It is an alternate ...

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20 views

Not entering ISR for timer 4 in stm32f4

I have coded for Timer 4 in a STM32f407vg discovery board. But while debugging the control is not entering the ISR. Please find the code below and help: ...
2
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4answers
71 views

Level vs edge triggering, usefulness of level triggering

Many processors / µCs / dev-platforms (BeagleBoard, Arduino,...) use interrupts. These can be triggered by the detection of: HIGH level RISING edge CHANGING level (either FALLING or RISING edge) ...
6
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1answer
55 views

Millis versus centis on AVR platform

I am building a device on the AVR platform. The device will need some timing information, so I was thinking of reimplementing Arduino millis-like functionality ...
0
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3answers
67 views

I'm trying to implement interrupt from RB pins. But it doesn't work

I'm new to PIC programming. I made a program to get interrupt from RB pins. but it doesn't work. My code is as follows: ...
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0answers
36 views

Two functions in the high priority interrupt

I'm using the PIC18F46k22 mcu and I'm using two function in my high priority interrupt routine: ...
3
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1answer
69 views

Are there platforms where disabling/restoring interrupts from ISR should be done differently than from non-ISR context?

I'm familiar with several real-time kernels: AVIX, FreeRTOS, TNKernel, and in all of them we have 2 versions of nearly all functions: one for calling from task, and second one for calling from ISR. ...
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2answers
42 views

Role of the MMU in a Page Fault Swap

When a virtual memory address outside the range of loaded into physical RAM is referenced and a page fault occurs, does the Memory Management Unit rely on DMA (Direct Memory Access) to swap the ...
1
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3answers
75 views

Returning from interrupts at a different location from where the interrupt occurs. (PIC16F877A)

Is there a way to return from interrupts at a different location from where the interrupt occurred in Microchip PIC16F877A? I have a problem where I need my code restarts at a specific point always ...
0
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1answer
35 views

Program aborts after ISR

First I am new to this and I signed in to get some help on this problem I have been having. I have done so much googling to figure this problem out and with no luck. I am trying to capture humidity ...
0
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1answer
26 views

Unexplained behavior pic port b on change interrupt

I am trying to configure the port b interrupt on change interrupts to work with a program I am writing with MC XC8 demo version. I am using a PIC16F628A I am using this code to initialize the pic for ...
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2answers
68 views

Catch both sides of a clock change PIC interrupt

I am trying to build an IR remote receiver using a PIC16F628A. To do that, I need to catch both the falling and rising edge of the external interrupt pin. From the datasheet it appears you can only ...
0
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0answers
34 views

LSM303DLHC data ready interrupt

I have a STM32F3-discovery board, and I have set up a little test. It just captures ALL input on GPIO3 and count them by channel. Then every seconds, I have a breakpoint with which I look at the ...
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0answers
38 views

8051 external interrupt INT0 issue?

How do I write an ISR greater than 8 bytes which is triggered by INT0?
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1answer
44 views

Measuring pulse length with ICP

I am trying to measure pulse length, with ICP (input capture pin) on Atmega8, coming from this circuit:. PINB0 is ICP pin on AVR. This is (most of) the code: ...
2
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2answers
152 views

STM32F103, Having trouble nesting interrupts

I'm trying to interrupt into a USART handler from inside an RTC_Alarm handler, but it doesn't work. I have set the NVIC: ...
0
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0answers
40 views

AVR TWI/I2C Not Responding

I use Twi module of AVR Atmega168 to talk to DS1307. ...
3
votes
1answer
82 views

SLEEP or busy-waiting. Which would service an interrupt faster?

I'm programming a PIC microcontroller to service two events via interrupts on a very time constrained environment. PIC microcontrollers allow a SLEEP mode which wakes the PCU on any external ...
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2answers
152 views

PIC18 xc8 compiler : how to resolve warning (335) unknown pragma “code”

I'm trying to compile this code to blink led with button interrupt, using xc8 compiler and PIC18F4550. I got those warning, so the code lines are ignored and the program doesn't work properly (by ...
1
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1answer
79 views

Implementing input capture correctly on a PIC

I'm using a PIC16LF1827 with the XC8 compiler in MPLAB X. I need to store the time between pulses that are coming from an external moisture sensor. The length of time correlates to the measure of ...
0
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2answers
84 views

Faster quadrature decoder loops with Python code

I'm working with a BeagleBone Black and using Adafruit's IO Python library. Wrote a simple quadrature decoding function and it works perfectly fine when the motor runs at about 1800 RPM. But when the ...
1
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1answer
107 views

STM32F1 troubles with a timer

I'm having some troubles with setting up a 1 second timer on STM32F103 mcu. I have set Timer 2 to have a prescaler of 1099 and a period of 65514, so I'm expecting to have a 1 second interrupt rate: ...
0
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0answers
65 views

Is USB UHCI polling-based or interrupt driven?

I've had a discussion with some colleagues whether USB is polling based or interrupt-driven. Some claim USB keyboards involve larger overhead than i.e. PS/2 keyboards due to the requirement of former ...
1
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1answer
81 views

Why does my Arduino DUE not recognize my external interrupt?

I'm simply trying to get my Arduino DUE to toggle a pin based on an external clock. I have a 14.31818 MHz Oscillator that is ...
0
votes
2answers
86 views

Calculating how many times TIMER1 will overflow

I'm trying to understand how to set up an overflow interrupt on ATmega328 TIMER1 to measure a frequency. I'm feeding pin PD4, which is where TIMER1 is externally clocked, with a 503kHz square wave ...
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2answers
83 views

ARM cancel execution of pre-empted interrupts

I can't seem to find an answer to this in google or the Definitive guide... Is it possible to from one interrupt, cancel the return to any pre-empted interrupts? For example, I have an ISR which is ...
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1answer
40 views

What is the danger of using interrupt pre-emption in ARM

I am working on a system which uses about 4 interrupts. I can clearly define a priority from one to the other. For example, I feed SPI transfers with DMA requests and operate a USB interface which ...
1
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1answer
57 views

Input interrupt pin associated with TIMER1 on ATmega168

A few days ago I came across the source-code for this ATmega168 based Inductance Meter from Dan's Workshop Blog. Below is the code that I believe sets up an ATmega168 interrupt to measure an external ...
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0answers
53 views

LPC2148 + Eclipse + yagarto + openOCD. Issue with the interrupts

I'm using 'Eclipse-Indigo' + yagarto + 'openocd-0.7.0' setup for a project on LPC2148. I've set up the environment properly. I'm able to compile, link and debug the project. I've configurred Timer0 ...
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1answer
183 views

STM32F103 Systick Interrupt stopped working when debugging in ram - (Coocox IDE)

I tried debugging my code in ram in order to increase the flash's life (only rated at 10k writes minimum) Anyways, I have tied the boot0 and boot1 pins to 3.3v and set the compiler to debug from ram ...
1
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1answer
50 views

The same flag for an interrupt

I think I'm mixed up a bit in NVIC of stm32 MCUs. I took a look in the SPI.h of the STM32F10x standard peripheral library. I don't know that why while there is ...
0
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1answer
57 views

Clearing Flag Bits By Writing 1

Most of the interface devices have various flag bits (that can also raise interrupts if that functionality is provided) used to check the status of the device/operation. Usually they are cleared by ...
0
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1answer
81 views

NRF24L01+ IRQ Issue

I am testing the functionality of NRF24L01+ and for my purposes I have configured it as PTX, No Auto ACK. I am able to communicate with the chip just fine and able to configure all the registers ...
0
votes
0answers
57 views

Spurious interrupts using switches on a Raspberry Pi

I have two switches connected to GPIO pins on a raspberry pi. One side of each switch is wired to +3.3v. The other side is connected to an input pin via a 330 Ohm resistor, and each input pin has a ...
2
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2answers
129 views

Interrupt Management - Large AVR Projects

This is for the more experienced one's out there. I am currently involved with a large AVR project (using ATMega328) and it's getting confusing with respect to interrupts. The project involves ...
1
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1answer
118 views

AVR bootloader restarts on interrupt

For a quite while, I've been using an avr ATmega324PA controller and Atmel studio to write the programs. we wrote a TCP bootloader. It works fine without any interrupt. Later we did add an external ...
0
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1answer
85 views

The GPIO External Interrupt doesn't work

I have written this program for GPIO External Interrupt but it doesn't work. look at the program: ...
0
votes
0answers
15 views

uC MPC5646CRM Interrupt source address

I am using an Embedded development software that needs the address of ISR in order to perform Interrupt. I am using MPC5646CRM Micro-Controller. The datasheet tells about the calculation of address. ...
4
votes
1answer
200 views

The LED blink even when I don't press the button

I have written a program in Keil for Blink a LED via External GPIO Interrupt. Ok, know I want to say you that how configured it in STM32CubeMX: At first, I enabled and configured RCC as you can see ...
3
votes
1answer
121 views

avr-gcc timer overflow interrupt handler in inline assembly

My current project involves producing 200KHz PWM waveforms using timer 1 in fast PWM mode. I would like to increment a 16-bit counter every time the timer overflows (every 5μS) ...
3
votes
1answer
97 views

AVR USART Random Behaviour

I seem to be getting random character in my USART output with an ATMEGA8 uart.c ...
0
votes
1answer
298 views

Can not jump to Timer interrupt function in STM32F4 discoverty

I made a code to call Timer2 interrupt function like this : ...
3
votes
1answer
162 views

To Clear or not to clear ARM Cortex-M NVIC interrupt pending

Do I need to clear the pending status of an interrupt in the interrupt service routine of an ARM Cortex-M0 MCU? Could not find information on this on the web.
2
votes
1answer
815 views

Stm32 Event and interrupts

I started studying interrupts on stm32 specifically the stm32f4 discovery board. i found this example in which you have to press the button to start the interrupt and push it again to stop it. In ...
0
votes
1answer
67 views

AVR- state change of a pin to generate an interrupt [closed]

I need to produce external interrupt whenever there is a change in state of a pin. When the pin goes from high impedance state to ground or from ground to high impedance state, an interrupt must be ...
3
votes
2answers
133 views

Periodic timer (64Hz) with ARM processor and (embedded) Linux

I want to call a function 64 times per second with a ARM processor which is running linux. (ex: Rasberry Pi or Freescale i.mx6). Ideally, I don't want too much jitter. I want to perform a task ...
1
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1answer
108 views

Is there a way to avoid an infinite loop and reduce CPU power consumption when using PIC and timer0 interrupt?

I have made a simple program that runs on a P12F629 microcontroller, using MikroC. I need ...
4
votes
1answer
28 views

How can I achieve a third interrupt priority level on 8052?

Most standard 8052 platforms allow the user to configure interrupts to be of two possible priorities: higher, during which any pending interrupt must wait, and lower, which can be interrupted by the ...
1
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1answer
73 views

How to detect which timer interrut called callback when using ASF?

I have a general function, which gets passed among others a timer. It initializes the timer using common callback function: ...
2
votes
1answer
80 views

Arduino: Generating time critical signals with interrupts

I have some problems to fully understand how interrupts on e.g. Arduinos/AVR are used in practice. Lets assume I want to generate a time-critical signal like PWM and at the same time be able to ...
4
votes
2answers
550 views

ISR - to flag or not to flag?

From what I read on the internet we should respond to interrupts as quickly as possible, when programming microcontrollers; and that flags should be avoided because they tend to compound over time. ...