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 dependent upon which interrupt was generated. Interrupts can be either hardware-sourced or software-sourced; software-sourced ...

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115 views

How to use UART rx data from ISR to main loop?

I am using PIC18F and currently trying to interface it with SIM900. I am using UART Rx interrupt. ISR is working correctly but I wonder how to get data in main loop. Lets say : ...
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1answer
40 views

FPGA Interrupt in FreeRTOS

I am using freeRTOS in Zedboard. I am able to enable the PL-PS interrupt in bare-metal program. I couldn't really find any documentation/tutorial on how to link the FreeRTOS and the PL interrupt ...
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1answer
26 views

AVR ATmega: can I trigger external interrupt by setting corresponding INTF flag bit?

I'm writing a C program for ATmega64A which has a INT0 ISR. This ISR should be executed in case of INT0 falling edge OR if the TIMER3 goes overflow. To avoid doubling the code I'd like to trigger ...
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0answers
47 views

How complex would it be to write code to wakeup a (unknown) core? [closed]

I'll ask all of you to assume the following. Take a PC CPU (any recent Intel i3/i5/i7 5th/6th generation) and assume there is an undocumented core that was not implemented by the Intel company. The ...
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0answers
21 views

Arduino Micro Cannot get Interrupt 6 work on PIN 7 [migrated]

After finding out about the situation with pin7 from this tutorial: https://forum.sparkfun.com/viewtopic.php?f=32&t=35847 ...
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0answers
35 views

STM32F4: WWDG interrupt fires as soon as it's enabled

I'm doing some coding on an STM32F411 board, used the CubeMX & HAL Libraries for laziness. I'm trying to get the windowed watchdog (WWDG) up & running, and doing the very basic version (non ...
3
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2answers
77 views

Pic16 Timer0 puzzle

INTRO The whole point of a timer with overflow interrupt is that the interrupt will trigger on a precisely timed interval - so long as the code executed in the interrupt doesn't take longer than the ...
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3answers
503 views

Logging multiple sensors data to SD card at same time: writing hangs up

I'm making a data logger project with 5 different sensors which includes a 3-axis sensor runs at 800 Hz. My requirement is to log the data to an SD card. Here I have to log 3-axis sensor @ 800 Hz and ...
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2answers
108 views

CMOS circuit design: How to implement an interrupt circuit that detects minimum or maximum peak?

I have an input signal sine wave like but comes with a little distortion. I need to give an interrupt when it reaches to minimum or maximum value with an acceptable tolerance. this graph is from a ...
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0answers
50 views

Timer causes UART problem

I have a problem, found on both ATMEGA1284P and ATMEGA2560. I have set a 16-bit timer in CTC (tried both Timer1 and Timer5) to give an interrupt every 1ms so I can increment a 32-bit volatile time ...
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1answer
111 views

ADC continuous conversion STM32F103

I'm facing with a problem regarding continuous acquisition of ADC channel in STM32F103. I use the interrupt at the end of conversion to call a callback function to store the acquired value. The ...
0
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2answers
135 views

Modifiying variable inside of Interrupt vector. AVR

My question is again about modifying variables inside the ISR. If the variable used only inside of ISR, I don't have to declare it as volatile, right? After some researching, I figured out that ...
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0answers
43 views

Use a computer's clock to accurately generate a refresh rate in higher level software?

With a microcontroller (e.g. AVR, PIC), we can setup timers and interrupts to generate quite accurate refresh rate signals, triggering pieces of code to run at precise, periodic instances. Is it ...
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1answer
39 views

AVR MCU running @ 32.7Khz Low speed LED multiplexing problem interrupt

Works fine with internal 8mhz, but when change to 32.7Khz, the multiplexing led display is not working properly (it's flashing very randomly). is this the limit of low clock speed or is there a ...
0
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0answers
40 views

Single touch On/Off auto off after 30 minutes

I've been looking for a circuit to turn on a strip of LEDS (12volts 5amps) with a momentary capacitive touch breakout board . I'm looking to have the lights stay on for 30 minutes or use the touch ...
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0answers
74 views

AVR interrupt setup seems to stop program execution

On ATMEGA168PA I have problems with interrupt-driven character reception over UART. When I include the line setup_interrupt() it seems that program execution stops ...
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2answers
118 views

Can this stm32f0 interrupt routine that activates on every byte received be fast enough for 6Mbps?

I am using the STM32F0 discovery board. I am looking at this tutorial on UART with the STM32F0. http://letanphuc.net/2015/09/stm32f0-uart-tutorial-5/ ...
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2answers
54 views

Generating pulses via timer match output or timer ISR?

I'm using LPC1778 uC for a project and want to know what is the difference between generating pulses via timer match output and via toggling a pin in a timer ISR. What are the pros and cons of both ...
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2answers
73 views

Methods of testing interrupts

I am maintaining and developing software in C for S12X micro controllers. The ISR for each interrupts (like I2C, Timer Interrupts etc) are very lengthy, like around 20 to 30 lines with several ...
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3answers
268 views

Polling vs Interrupt: which one is first in a bare-bone piece of hardware?

First of all, I must say that I have a computer science background, and I don't have much knowledge about hardware. I would like to ask this question because in software, what I often see is a loop, e....
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1answer
55 views

Large timer interrupt instructions [closed]

Assume that it takes the micro-controller 1 microsecond to execute an instruction and the timer overflow has also been set to 1 microsecond and in the timer interrupt handler we have some instructions ...
0
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1answer
59 views

Variations in pulses generated and read by a uC

I have a 2 uC's(LPC1778 and a PIC), that perform 2 separate functions. The PIC generates pulses that are coded,where each bit of the code has a pulse duration of 1ms and a complete code is 8 bits long(...
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1answer
53 views

Priority among prioritised interrupts

I am using 2 interrupts on LPC1778. One for CAN and one for timer. The CAN interrupts whenever a new message is received. The timer interrupts every 200uS. The priority for timer interrupt is the ...
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3answers
143 views

Uart Transmit every 1µs Interrupt StM32 NucleoF401-Re

I am using the STM32 Nucleo F401-RE and HAL libraries. I would like to send value through UART to the PC console every 1µs interruption. Actually I want every 1 µs interruption to increment a ...
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3answers
93 views

Deciding Timer Interrupt time

I have used timer interrupt in my application, mainly for timing reasons like timeout detection for processes,pulse generation etc, every 1 ms. Now i have a doubt. Suppose in main(), if im doing ...
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0answers
34 views

Is Energia buggy when it comes to using Serial.print() near sleepSeconds() call?

So, I've been experimenting with sleep, sleepSeconds, suspend() and wakeup. These are AWESOME by the way... Here's what I've found. suspend() puts the controller into LPM4 which makes it ONLY come ...
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1answer
50 views

How do you implement an Energia interrupt handler?

So, I have an application that needs to be very conservative with the power. I use the suspend() command to go into LPM4 and wait for an interrupt to occur. During the interrupt, I attempt to ...
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1answer
76 views

How do you use low-power mode on an MSP430G2553 using an Energia sketch?

I am using an energia sketch to program my MSP430G2553 controller. I need to know how to use low-power mode. Do I leave the loop section of the sketch empty and set up an interrupt in the setup ...
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1answer
125 views

How to count using Interrupts

I have an issue where I want to count how many times I hit a switch using an interrupt. I tried placing the count variable inside the main but it claims that count does not exist. I put count inside ...
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1answer
129 views

How to use the Non Maskable Interrupt on SAM4S?

I'm trying to use the NMI on a SAM4S (Cortex M4), but I'm finding some hard time to make it work. The main objective is to jump to the NMI handler whenever the power is about to go down, so that I can ...
1
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1answer
62 views

Does Interrupting a Microcontroller Data Receive with a Higher Priority Interrupt Cause Data Loss?

I would like to know what would happen if a Serial Terminal were to send a large amount of data to a PIC/AVR, for example over USART interrupt, which was then interrupted by a higher priority ...
2
votes
2answers
115 views

Reset Interrupt - Beginning or End of ISR?

Im working on a uC that has interrupts configured for various FIFO's present in the uC. Each FIFO is connected to a common bus and can receive data independently(at any point of time). Now, everytime ...
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1answer
163 views

stm32f207 ethernet interrupts problem

I installed RTX (rtos from Keil) and Ethernet library from STM for stm32f207 MC. I configured UDP using ethernet + LwIP as in examples from STM. Without RTOS UDP works fine. I send and get packets ...
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2answers
636 views

Enable interrupt but no ISR

I would like to know what happens if an Interrupt is enabled(ex:Arbitration Lost Interrupt in CAN module of NXP's LPC1778),but no ISR has been defined for the interrupt. When such an interrupt occurs,...
0
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2answers
282 views

STM32: UART Interrupt is triggering without any flags getting set

I am using the UART4 module of an STM32F105. I'm using the RXNE ("RX Buffer Not Empty") interrupt to grab data as it comes in. It's working as expected. When the RXNE interrupt is enabled it also ...
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1answer
93 views

Interrupt programming PIC18F4520 :: Toggling LED

[Edit: replaced sideways photo with upright photo] I recently started using interrupts in pic programming. I started with this program but I am not able to go through what has been done in this ...
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2answers
117 views

Difference between FIQ and IRQ

Im working on TI based processors now and they have 2 types of Interrupt configuration(FIQ or IRQ).I have seen such interrupts before when i was doing a hobby project using a LPC1778 but since i didnt ...
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0answers
71 views

Context Switch without interrupt disabled?

I developing a program on ARM M4 where I don't actually want to disable interrupt even when doing a context switch. If any interrupt occurs during context switch, is it possible to handle it soon ...
2
votes
2answers
90 views

Systick interruption doesn't trigger when handling another interrupt

I am experimenting with the STM32f4 discovery and i tried to use a delay (based on SYSTICK) in an ...
0
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2answers
106 views

Sensing Voltage with a Digital Pin

I am relatively new with Arduino and did a little bit of research prior to this post. But I am trying to sense when I have voltage coming from an AC/DC converter (12Vdc) so I can switch from my ...
4
votes
1answer
274 views

UART Interrupt does not get more than one Char - PIC32MX110F106B

I am really struggling with an UART communication with my PIC32MX110F016. It is the first time I am trying to implement an UART communication with PIC32MX family but I find it difficult and I don't ...
1
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1answer
573 views

Clearing USART (UART) interrupt flags in an STM32?

I am using an STM32F105 to communicate with a Linx GPS chip using a UART. If I don't use interrupts (if I just poll the RX flag) then it works just fine. But I'm getting unexpected results when ...
0
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1answer
130 views

MSP430 Problem with Multiple Interrupt Timers

I am currently investigating the use of pulse density modulation (PDM) combined PWM (In short, PDM-PWM) as a substitute for conventional PWM in the application of maximum power point tracking (MPPT) ...
0
votes
2answers
94 views

Detecting interrupt on Atmega8 from zero crossing detector circuit

I have a zero crossing detector circuit, whose output I am providing to my Atmega8 as an interrupt, but unfortunately its not working. If I use DC supply 5V (logic 1) as an interrupt, it works. Where ...
3
votes
1answer
99 views

AVR external interrupt triggering by the falling edge: for how long should I keep signal low to guarantee triggering?

The question header appeared to bee too long. I'm sorry for that. So I have a schematic generating a short LOW on INT0 pin of ATmega48PA. From the simulation I figured out that the LOW level will be ...
18
votes
2answers
1k views

Should all traps always be defined?

I've seen two cases now with dsPIC 30F4013 where the controller was resetting due to an undefined trap. Why these traps were getting raised in the first place is still a mystery, but that's not my ...
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2answers
64 views

CAN -> acceptance filter then interrupt or vice versa

I would like to know which occurs first while using CAN communication. Based on the answer I would conclude whether an acceptance filter must be used in my project or not. Scenario: There are three ...
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2answers
120 views

Serial Communication Rx ISR logic design

If im not wrong, an ISR is supposed to do minimal processing when it receives a data serially(via UART). Im planning on implementing such a protocol for communication between 2 systems via uart. This ...
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2answers
72 views

PIC16 10hz timer with timer1 and 1Mhz clock

I need to increment a stopwatch at 10hz using timer1 on a PIC16F628. The external clock is 1Mhz, supplied by a packaged oscillator (EPSON sg8002db). With no prescaler, the value to set the timer to (I ...
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0answers
68 views

How to set MSP430 Driver Library timerA configurations

I am using MSP430F5529 and MSP430 Driver Library. As you can see, I set upMode timer configuration, compare mode configuration and enabled the initial interrupts. However, timerA interrupt is not ...