Questions tagged [timer]

Circuit to generate a signal a specific time after a trigger event. The timing can be defined by an RC time constant, or by clock pulses from an oscillator.

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3answers
156 views

Can I use an RC network somehow to allow reading of initial values from jumpers into a micro controller?

I completed a microcontroller project but I want to add a feature where when it starts up, it can read a 4-bit value defined by on-board jumpers (jumper closed = logic low, jumper open = logic high ...
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1answer
327 views

Stm32F103 DMA TIM1 - Load 50% of period.

I wrote a code using DMA with TIM1. In DMA buffer i load diffrent periods and send to ARR Register. How Can I change a Pulse of PWM to 50% from Dma buffer ? ...
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2answers
274 views

8051 baud rate calculator using 16-bit timer for software UART timing

I'm making a project in which pulsed laser beam data is sensed through many optical sensors (one sensor per port pin), so essentially, I'm going to be making 4 UARTs to sense this. Currently I am ...
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3answers
680 views

__HAL_TIM_GetCounter with STM32F103

I found a lot of tutorial to get counter value from an interrupt timer something like: ...
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1answer
36 views

SAMD21 1μs timer handler taking longer than the timer period?

Before I begin I'd like to mention that I'm relatively new to working with microcontrollers at this low level, so please bear with me. I am trying to use an Adafruit Trinket M0 to process and ...
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1answer
437 views

STM32405 ADC on Update Event of Timer 1 or 8

I'm not sure what I should be asking for because some of the terminology is confusing to me, but what I'm trying to do is use the two motor timers (TIM1 and TIM8) on the STM32F405 to sample BEMF on a ...
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1answer
163 views

How can I use the component CD4538 or a 555 timer on Multisim?

How can I use the component CD4538 or a 555 timer on Multisim for a delay of 1 second ? I want both of the nor gates to be 1 for roughly 1 second when the output of the op-amps is either 01 or 10.
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34 views

How to adjust STM32 PWM start time dynamically

I have two devices that I need to keep synced using a PWM of 1 second on and one second off. I have control over telling one to start a new cycle (this is done once every 60 seconds using a gps), and ...
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1answer
544 views

Control a 12 v circuit using wall plug 220v ac timer

I want to use a standard supermarket 220v ac timer to switch a 12-volt circuit. I was thinking about letting the timer run on the outlet, and just desolder the relay separating it from the ac, keeping ...
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5answers
2k views

Astable 555 circuit not oscillating

I'm a complete beginner to electronics, but I'm trying to follow Ben Eaters video series "Building an 8-bit computer". I tried to do the first part of an astable 555 timer, but the LED does not ...
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2answers
161 views

What is the best way to implement a microseconds precise delay/measurement [closed]

I recently saw some people saying that configuring a timer so that it triggers an interrupt each 1us is not a good way of doing that. Also, I assume that; ...
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4answers
91 views

What happens if an interrupt callback execution is interrupted by the same interrupt?

I have a microsecond timer (generates interruption every microsecond) for which I implemented a "HAL_TIM_PeriodElapsedCallback" function. What occurs if the ...
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1answer
84 views

How to increase ON Time of a Relay?

I am trying to increase the ON time of a Relay. The Relay is turned ON from ULQ2003 by a 1 Sec ground pulse on its OUT1 Pin. I am trying to increase it to approximately 3 Sec. The accuracy of pulse ...
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3answers
2k views

Momentary-Pushbutton Latch Switch with off delay?

I am trying to construct a latching circuit with a 1-2 minute shutdown delay so I can soft start/stop a 240V-5V power supply. I am looking for a momentary push latching (on-off) circuit to switch the ...
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0answers
51 views

Atmega328p datasheet mistake “OCRA”

I was reading the atmega328p datasheet, and suddenly, i saw that a register is mentioned called "OCRA", on page 108 and page 160, which normally, should be register "OCR0A", which is widely mentioned ...
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1answer
67 views

Multiple NE555 timers, disable retriggering until all have finished

I plan to build a small timer device that, when triggered, lights up 3 leds. After 30 min, the first goes dark, after another 30 min the second and yet another 30 min later the third. It's pretty ...
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0answers
54 views

STM32F103 timer behaves differently after hardware reset instead of st-flash reset

I'm learning to program the STM32F103C8 Cortex-M3 (on a BluePill board) and was playing around with the general purpose timers (TIM2 to TIM5) because I wanted to time some routines. In my simple ...
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1answer
85 views

One led is blinking too frequently using the hardware timer (stm32f103vdh6)

i recently started my internship using embedded C and i'm having some trouble with one of the tasks: Two leds should be blinking at 1Hz, one using the hardware timer, and the other one using the RTX ...
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0answers
28 views

Simulation behaves differently in Proteus vs Icircuit

I'm an electrical engineer student and I'm trying to make an LED Flasher circuit using a 555 Timer. When I simulated the circuit in Proteus simulator, it's not working! But in Icircuit simulator it ...
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2answers
104 views

Timer Protection Circuit

I need to create a circuit that sends out a signal only if the input it on for longer than a specified time. Lets say 20 seconds for this example. So if the input to the circuit was pulled high for 10 ...
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1answer
43 views

LTC6991 : unexpected ouput signal

I'm trying to make a 50% oscillator with a Tout=10ms period. Instead, I get a 5.7ms period signal, and an off pulse (low level) of 150µs ! I chose POL=0 and RESET is grounded. From table 1 of the ...
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1answer
92 views

Timer0 in PIC18F26J50

I have a PIC18F26J50 and I want timer0 to output a 1Hz signal on RA6. I'm now getting ~800Hz with my current setup. Clock is 48MHz / 4 = 12MHz on RA6 (if INTOSCPLLO is enabled). Compiler is C18. Here ...
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2answers
74 views

How to configure PWM on STM32F429I-Discovery Board

Currently I have some difficulties on the Discovery Board STM32F429I to control the on-board LEDs via PWM. According to the data sheet of the Discovery Board the LEDs are located on pin 13 and pin 14 (...
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1answer
30 views

Is Compare Pulse sooner than OC1REF in STM32 Advanced Timer output trigger

The options for trigger output signals seem not very well documented. According to the datasheet (P509, here) they include: Compare Pulse - The trigger output send a positive pulse when the CC1IF ...
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1answer
62 views

STM32F4 input capture

How can get input capture values from STM32F4 for measuring the duty cycles of the four different signal? Here is one channel code: ...
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1answer
118 views

LM555 timers for control of a secure door

I will explain existing hardware followed by my desired operation thereof. I have a security door the controller of which has failed. The door has four electronic deadbolts. -- A) Two open ...
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1answer
103 views

Aircraft Starting Mockup Display With Buzzer Question

I am stuck in the middle of building a circuit for an aircraft starting mockup that will train our students to correctly start the aircraft without accidentally re-engaging the starter and thus ...
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1answer
48 views

Signal low delay for specific amount of time / hardware - equivalent of Arduino pulseIn() function

I have a circuit similar to the following: (Source: electronicsforu.com - Shadow Alarm: Light Sensitive Circuit) In the circuit, the output from op-amp pin 6 goes low when a shadow falls or light is ...
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1answer
107 views

Speed limiter - turn off a motor if a fixed speed limit is exceeded

I want the cheapest, most basic method of turning off the motor while an electronically assisted vehicle is moving at over a certain fixed speed. I don't need to measure the speed other than it being ...
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3answers
223 views

555 timer not switching at threshold voltage

This is a 555 timer circuit which is supposed to generate two short pulses, back to back, at a regular frequency. The top 555 is configured as astable to control the frequency. It feeds the first 555 ...
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1answer
66 views

Simulated 555 timer not working

https://www.tinkercad.com/things/2CN1eOTbmTe I am a beginner in electronics. I've been trying to make an astable 555 Timer in TinkerCAD as an oscillator for my own project of making a clock, without ...
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1answer
1k views

Short circuit detector (autoreverser circuit) using current sensor and switching relay

First of all I’m not electrical engineer. The original idea is described here. It is a model railroad problem. The rails are carrying a power signal (DCC) 12-18 V. The frequency is ~17 kHz. It is a ...
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1answer
30 views

How to configure a clock rate of 50 Hz with a prescaler with TI Microcontrollers?

I need to configure a display that updates its values with f = 50 Hz. Since the CPU works with 16 MHz and the prescaler has a max. value of 256, the min. clock rate I can compute is 62.5 kHz. How do ...
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1answer
103 views

strange array values (C, psoc, usbuart)

I am still fairly new to programming, so I'm sorry in advance if my terminology/formatting isn't up to scratch. I am currently working on an element of a musical instrument that will allow me to ...
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2answers
71 views

What is the difference between IQRn 0 and IRQn 1?

I am using STM32CubeMX to program my chip. Essentially I have a timer that i am trying to set to one ms, and every time that timer reaches a ms I want to toggle a pin. My question is that does it ...
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1answer
36 views

2-time constant (On + decay) timer circuit

Required is a timer circuit to switch on an LED with 2 time constants, when a switch is depressed as follows: when switch is closed, light an LED 10 ~ 20mA when switch is opened again, keep the LED ...
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0answers
49 views

CircuitLab simulation of 555 timer - OUT HIGH always delivering 5V irrespective of Vcc?

I've scratched together a design for a 555 timer based driver for an IR540 MOSFET. But in CircuitLab the simulator shows the 555's OUT voltage is always 5V when high, for Vcc ranges 3.3V through 24V. ...
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3answers
115 views

Minimal components for timer relay

A 5V LED should run for a predefined time period once a button is pressed. The LED should be illuminated for the same duration as the button is pressed, but only once the button is released and ...
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1answer
22 views

How to do a counting of a timer configured in Mplab Harmony framework?

I'm new to harmony framework, and am trying to find how i can count timer iterations, so i'm doing a simple test. I configured the timer like this: Now i want to know if this is the correct way: <...
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1answer
41 views

Anyone knows what is a driver implementation in Harmony?

When configuring a Timer Driver implementation the option for Dynamic and Static appears. Anyone knows, what does these 2 types mean?
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1answer
3k views

Dinamically change PWM frequency with interrupt with STM32

i'm using an stm32f4 to control a stepper motor. I'm not sure if i need PWM mode or OC Mode or OnePulse Mode. I can generate a fixed frequency PWM wave but since i need a particular acceleration/...
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3answers
110 views

What Is the timer period of a timer of a Pic

This is causing a bit of confusion to me. I'm assuming that timer period of a timer is the time that it takes for an increment of timer. Am I correct? It works the same way for 8-bit and 16-bit timer,...
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1answer
133 views

Generating a short pulse after a delay on ATmega 328/P

I am trying to use one of the hardware timers on the ATmega 328/p (arduino uno) to generate a short pulse some number of microseconds after receiving a pulse on an input. Currently my code looks like ...
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1answer
131 views

stm32f407 timer setup stm32duino

I'm trying to understand how timers work in this board. I want to make a simple led blink after X amount of microseconds and then keep the led on for X amount of microseconds ...
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1answer
50 views

Does the increment of a timer on pic is equal for a pic16 and pic32?

The question is because in porting code from a PIC16F15324T using MCC to a project using a PIC 32MX470F512L. There are portions of code where i have code like this: ...
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1answer
44 views

Basic timer that doesn't work STM32L4

I'm trying to use timer2 in STM32L475 but it doesn't start firing the interrupt at all. I would like to configure the timer for a minute. ...
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1answer
60 views

Configuring STM32 timer as frequency counter

I am trying to configuring one of the timer inputs on a STM32 to behave as a frequency counter for an external signal. The STM32 datasheet describes a "input capture mode" in section 17.3.6 (page 342) ...
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0answers
84 views

Is there a minimum frequency in PIC32MX470F512L?

I'm still an inexpirient and I'm configuring the PIC, through MCC (Microship Code Configurator) So i set in the MCC a TMR1: The configuration for the ...
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0answers
48 views

The interrupt callback happens at the calculated period of the timer in pic?

I'm trying to set the timer of a PIC32MX470F512LT to happens every 8us. But after seeing on an oscilloscope when the callback of the timer it doesn't seem to ...
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2answers
25 views

555 Timer with controllable reset

I have a 555 monostable set up which is triggered when an output from another circuit goes low. This then remains on for 10s. This all works almost perfectly. My issue is that when the output from ...