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 ...
3
votes
1answer
40 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
58 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
33 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
1answer
55 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
vote
1answer
62 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
22 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
vote
1answer
30 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
56 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
524 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.
...
1
vote
1answer
169 views
Global variable in AVR interrupt routine
I am writing a code with interrupt routine. For debugging the code am using uart. So, here is the snippet
...
0
votes
0answers
67 views
Cortex M3 GPIO Interrupt won't trigger
I have set a pin on a Cortex M3 to act as an rising-edge triggered interrupt and it's not firing for some reason. What it should do is receive a 1Hz pulse, trigger an interrupt and start a 12.8Khz ...
3
votes
1answer
109 views
Multiple simultaneous Interrupts PIC 16F88
I'm new to PIC microcontrollers ( I have some experience with Arduino but wanted some "real" experience =P ). I got myself a PIC16F88 and I now intend to make a simple robots who's 2 DC motors are ...
1
vote
1answer
210 views
AVR SPI slave with interrupt
For a project I want to have two microcontrollers talk to each other via an SPI interface. I wrote the following code for the slave:
...
0
votes
0answers
54 views
Application of intel 8253 timer
8253 timer works in 6 different modes namely interrupt on terminal count, hardware-retriggerable one shot, rate generator, square wave generator, software triggered strobe and hardware triggered ...
1
vote
1answer
88 views
Two interrupts for a single operation
I am using infineon XC866-1FR controller for my project. For the motor control, I am in need of exciting the coil by the combination of two external interrupts(external interrupt 1 && external ...
0
votes
1answer
115 views
Netduino Interrupts Affected By PWM - Diagnosis of Issue
I've got a funny problem with interrupts and PWM signals that's causing false interrupts to trigger. What exactly is happening is that I'm using a hardware debounced quadrature rotary encoder. The ...
5
votes
2answers
291 views
Attiny85 hardware interrupt unreliable, 433 MHz remote
SCROLL DOWN TO SEE THE SOLUTION (UPDATE II)
ORIGINAL POST:
I am currently building a 433MHz remote with two buttons. The remote is controlled by an Attiny85v(8MHz). Sadly it does not work very ...
3
votes
4answers
211 views
Available Guidelines for Interrupt Driven Processing
Are there any available guidelines for the amount of code to have in a critical section of interrupt driven processing?
My personal rule of thumb is that the critical portion, (i.e. that between ...
0
votes
3answers
159 views
Good flag practices - energia msp430
I'm making a program for the msp430 using energia launchpad, the first code that I had is the following:
...
1
vote
1answer
82 views
Identification of hardware interrupts in microprocessor 8085
I am familiar with the RIM and SIM instructions that are available in the instruction set of microprocessor 8085. And thus I can enable RST 7.5 and RST 6.5 interrupts using SIM instruction and EI ...
1
vote
1answer
76 views
Things to do with ISR
I have an ISR that increments a counter every 5ms if the switch is pressed.
If the counter becomes 200 then do Reset. I plan to add more functions to be called from the counter value.
After a few ...
1
vote
1answer
148 views
Interrupt Service Routines and I2c together
I would like to ask a question that has been on my head for a while
I have done coding small ISR's for pic and AVR controllers and i have successfully tested them on board.And i have just learned ...
0
votes
1answer
80 views
Saving the last value used in an ISR
I am using a level-triggered interrupt. During the interrupt OCR1A increases and the servo moves. I want to save each value of OCR1A when the pin returns to its previous level. So far I have only been ...
3
votes
2answers
147 views
How can I wake up an ATtiny84 microcontroller at specific time of the day?
I am trying to create an alarm that wakes up at a certain time and does a series of instructions. To set the times that it wakes up, I am going to use the headphone of an Android device to send ...
0
votes
1answer
38 views
LM393N with hysteresis and potentiometer
I am having a bit of a problem with this next circuit:
The problem is, when there is 0V at the base of Q1 and when the potentiometer is set close to 100 kOhm. Because of the hysteresis set on LM393N, ...
2
votes
1answer
133 views
Task handling in firmware
I would like to get an advice on handling tasks in a firmware.
I have 3 major tasks to do:
Scanning for whether a switch is being pressed or not.
Data transmission via SPI - To EEPROM
Data ...
2
votes
1answer
720 views
STM32 Rotary Encoder with Hardware Interrupts
I'm trying to get a rotary encoder working on my STM32.
I have channel A & B being pulled up to 3V and debounced with 1uF capacitors.
The board has channel A & B connected to PA11 & ...
0
votes
0answers
142 views
TXE bit won't clear UART ARM M0
I'm trying to get UART working on a STM32F0 part and can't figure out the interrupts. According to the reference manual
...
0
votes
1answer
126 views
STM32F207 I2C errors
I am learning embedded development on the STM3220G-EVAL board with the STM32F207 microcontroller. I am testing the I2C interface by interfacing the two I2C2 and I2C3 modules on the same chip and ...
1
vote
1answer
100 views
Measuring rotations problem with motor encoder
I have this motor encoder mounted on the back of a 120RPM motor which has a gearing of 298:1 ratio. The back shaft is directly from the motor, not through any gears.
Im using an encoder disk that has ...
3
votes
2answers
135 views
Preemptive Interrupts and “Context Switching”
In RTOS, when a Higher Priority task becomes Ready to Run, it stops or preempts currently running (Lower Priority) task and start executing itself. Before switching tasks, RTOS saves required data ...
0
votes
1answer
70 views
SmartFusion debug problems
I am using an Actel SmartFusion system-on-a-chip, running a bare-board application that uses the MSS with SPI, ACE and GPIO. (I am developing in Libero IDE 11.1 and SoftConsole.) My program ...
-1
votes
2answers
97 views
What happens when the same interrupt is caused during an ISR? [closed]
To handle an interrupt the processor jumps to an interrupt service routine (ISR). If this ISR generates the same interrupt then this can result in:
a) program error
b) hardware error
c) stack ...
3
votes
2answers
98 views
How interrupts handle does work on a physical layer
I want to understand how HW IRQ does work on a physical layer. I ask my question considering a specific example. As known after a packet coming to a network adapter a hardware interrupt is signalling. ...
1
vote
1answer
1k views
Use AVR Timer1 for Compare Interrupt AND PWM at same time
Is it possible to use Timer1 on an ATMega to generate a compare interrupt on OCR1A and PWM output on OCR1B? I've tried with similar to the following, but neither work with everything I've tried.
...
4
votes
2answers
297 views
MSP430: how to let the timer ISR interrupt the Serial RX ISR?
I am working on a MSP430 connected to the PC via serial. The MSP430 also communicates with some other boards using a bit-banged serial interface. I'm using the timer peripheral to bit bang the serial, ...
2
votes
2answers
61 views
Use interrupt to determine a change in IR detector
I have build a schematic to read a counter. The counter has a white point at one of the digits, that I detect with a IR transmitter-receiver. The voltage at the receiver changes from 2.2 to 2.5 volts ...
1
vote
1answer
228 views
dsPIC33 Simple External Interrupt problem
This will be laughably easy for someone who has worked with the dsPIC33 and XC16 compiler, but has already cost me a day. Hopefully someone can save me any more wasted time!
Could someone please tell ...
0
votes
1answer
261 views
Inverting interrupt edge (STM32 wake up pin)
A sleeping STM32 can be woken up by a rising edge on its wake up pin. But if the IC on the other end of the line only interrupts as falling edge, is it possible to invert it somehow ?
1
vote
1answer
113 views
Interrupts and Arduino EthernetShield
I'm in need of a little guidance in a project I'm working on.
Basically, I'll be using two arduinos:
The first one will have:
1 RF Link Receiver (linke here: ...
1
vote
2answers
694 views
Toggle OC1A, OC1B and OC1C using timer in CTC mode
For most AVR MCUs for each timer they got 3 dedicated pins (eg. OC1A, OC1B and OC1C) that can be toggled automatically when the counter reaches the so called top value in the corresponding 3 registers ...
2
votes
1answer
148 views
AVR Interrupt “Interference”
I'm currently working on receiving signals from an RC remote. I have used pins A8 to A15 on my Arduino Mega board.
The ports and interrupts are setup with the help of this code:
...
4
votes
1answer
181 views
ATtiny45 pin change interrupt PB5?
On the ATTiny45 data sheets it states that PB5 can be used as a digital IO pin and I want to use it to trigger a pin change interrupt, my only issue is that it is also the reset pin and the moment I ...
0
votes
1answer
330 views
MikroC Hardware Interrupt
I am trying to program a PIC 16F876A using mikroC. I need the program to run when I push a button to a certain point, stop and wait till the button is pushed again before finishing.
...
3
votes
2answers
133 views
Sending a rapidly changing variable through SPI
I am trying to send the value of a counter running in timer1(32bit) to another chip, ideally through SPI. The timer triggers an interrupt every 1ms to increment the counter. Overall, the variable ...
0
votes
1answer
113 views
AVR Timer for PWM and interrupt?
I am developing a system that needs to drive 4 stepper motors through 4 dual H-bridges, for each phase of movement the AVR will receive SPI messages stating how many steps each motor should do and ...
1
vote
1answer
92 views
Atmega169PA interrupt source
Is there a simple way of determining which module causes an interrupt on an ATmega169PA? I have 3,000 units executing the same code and there were 10 units that executed my ISR(BADISR_vect) handler ...
1
vote
2answers
161 views
Why vectored interrupts are not possible?
vectored interrupts are not possible if a cpu has single interrupt request line and single interrupt grant line while multiple interrupting devices are possible .
Is the above statement is correct ...
3
votes
1answer
377 views
Migrated from C18 to Hi-Tech C 18.. Interrupt not working
Here is my source code. This code is working perfectly fine in C18 Compiler. Not until I migrated to Hi Tech C. It does not enter the interrupt service routine. Moreover, it somehow corrupted sid ...
3
votes
1answer
2k views
PIC: how to set timer0 to give an interrupt at every 1 sec?
I am programming a PIC18F67K22 and I've set it to use a 16X4Mhz Internal RC oscillator with PLL enabled.
-High level interrupt on TIMER0 overflow
-I am using ...
