Episode #125 of the Stack Overflow podcast is here. We talk Tilde Club and mechanical keyboards. Listen now

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.

Filter by
Sorted by
Tagged with
0
votes
2answers
83 views

How can I make a 10 minute and 15 minute buzzer timer? [on hold]

Basically, I have a big project going on in my campus which we were told to make digital counter. So when the timer counts reach at 10 minutes (by this case, the timer counts is shown by 7-segment ...
0
votes
0answers
36 views

Simple LDR circuit calculate average time between triggers

I am a beginner with some past experience in electronics. I have a circuit that uses an LDR and 555 to display the time (lap time) between the LDR being triggered - start / stop - on a 7 segment unit. ...
0
votes
1answer
68 views

What is the problem in my timeout implementation?

I'm trying to use a DHT22 (temperature and humidity sensor). Here is its datasheet: DHT22 Datasheet In first few seconds, I can get values. But after a while it gets stuck in here: So I tried to ...
0
votes
2answers
38 views

555 PWM motor driver controlled by external analog signal

I used the below 555 timer PWM circuit to control the speed of a dc motor, and it works like a charm :) now i have a requirement to change the PWM speed externally from another module, that module ...
0
votes
0answers
5 views

How to replace a manual timer by a simple on/off switch on a home appliance [migrated]

Case On a simple 220v home appliance equiped qith a maual timer switch ( a knock that you can turn clockwise up to the desired position -time- and will then automatically turn counterclockwise for ...
0
votes
2answers
59 views

2-Bit timer with 1 ms period

I am trying to find a simple hardware solution to implement a 2-bit timer that gives out 2-bits continuously repeating data 00, 01, 10, 11, 00, 01.... whose time period is approx 1ms. The accuracy and ...
0
votes
1answer
38 views

PIC18F26J50: timer0 issues

I'm implementing timer routines using timer0. The goal is to have a 1ms timer routine so I can use it for general proposes. The problem is that I'm getting a 13kHz waveform in RA6 and I intended to ...
0
votes
1answer
50 views

Simple blinking Led with control over both the pause rate and flash time?

I was hoping someone could help me understand a very simple approach to creating a flashing led. While many simple examples exist, I cant quite find one that allows me to control both the pause rate ...
0
votes
2answers
41 views

Help with 74HC393

I'm learning how to use ICs and am currently playing with a 74HC393. Since it contains 2 independent 4 bit binary counters I am trying to connect both sides of the chip to make them work together. ...
0
votes
1answer
45 views

Why should we charge the capacitor halfway in 555 timer circuit(as given in datasheet)?

In the Texas Instruments datasheet for LM555 IC, at Page 11 below Figure 15, the calculations for charging and discharging of the capacitor are given. In those calculations, the capacitor is made to ...
1
vote
3answers
50 views

Adding different voltage battery to same circuit

I have 9 volt battery to get 5 volt using step down converter. I want to enable the step down using a timer IC max input voltage 6 volt. I will use 3.7 v battery for this. So my question is: Can I ...
1
vote
1answer
37 views

M2P DMA transfer with trigger from a different peripheral

The microcontroller on my board is STM32F429IGT6 and I want to use a timer as a trigger of a DMA -e.g. HTIM_SOUND_SAMPLER- and transfer my data from an array to CCP of another timer -e.g. ...
0
votes
3answers
67 views

STM32 ADC and timer(s): Measuring moving average peak voltage of PWM signal with varying amplitude

I want to measure a moving average of the amplitude of a fix frequency, fixed dutycyle PWM signal with slowly varying amplitude but in a noisy environment (DC motors). I want to use as little as ...
0
votes
2answers
58 views

555 Timer - How to quickly discharge RC capacitor

I'm using a 555 timer to turn off an LED with delay. Here is the circuit. All I want to implement is, to get the input voltage changes in output with a constant delay. When I close the switch, the ...
-2
votes
0answers
41 views

timer as a counter for one second led toggle in stm8l

Can anyone explain how this calculation works in this timer configuration. I am using stm8l-discovery board and when I see the waveform, i get a graph of 1s for one complete on-off cycle. ...
0
votes
0answers
37 views

Convert NE555 square wave output to triangular wave using op-amp(s)

I want to generate a square wave with 45% duty cycle and 465Hz on an NE555 timer and then convert that wave into a triangular wave using op amps. I have a circuit schematic but the output generates ...
0
votes
0answers
25 views

How to calculate Pulse width using TIMER in Capture Mode

i am trying to implement Atmel example about using TIMER0 Capture Mode to measure duty and frequency, you can find the full example at Github At (CCA ISR) we have the following code: ...
0
votes
1answer
41 views

timer input capture for really low frequencies

How low of a frequency can a timer be used to measure an external signal in "input capture" mode? If I need to measure something that has a frequency of say 1hz - 2hz... or even slower for that ...
0
votes
1answer
45 views

PWM frequency and sine waveform generation

I am trying to follow some guides (for instance this) to generate some analog signals (for instance a sine wave of 50 Hz) with Arduino (but my questions are general). But I have two basic questions: ...
0
votes
2answers
45 views

Oscillator configuration for PIC24F proteus

I'm trying to simulate a PIC24FJ in proteus for the most realistic way but even tough proteus is running the simulation it doesn't allow me to configure HS or XT oscillator for primary oscillator ...
1
vote
1answer
46 views

Power-on delay with 555 Timer

I am trying to create a power-on delay with a 555 timer IC. I have never used one of these before and I am finding it a bit tricky to make applications with it - a lot going on. I found this circuit ...
2
votes
0answers
41 views

Cortex-M DWT cycle counter inconsistent measurement

I recently discovered that it's possible to use a free running counter embedded in most Cortex-M4 cores to measure the performance of a chunk of code. I'm trying it on my LPC4370, where I want to ...
1
vote
3answers
76 views

triggered PWM from ADC end of conversion

I am making a full bridge control on D-SMPS and I want to trigger PWM from ADC to keep output voltage constantly stable. I am using STM32f103xx as microcontroller. The problem is that looks like in ST'...
0
votes
2answers
149 views

VHDL internal timer not consistent time

I'm having inconsistent times on my timer, can be anywhere from 300ms - 4 seconds, what could be causing this? The code logic looks good to me but the oscope shows different times almost everytime I ...
2
votes
1answer
43 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 ...
0
votes
0answers
41 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 ...
2
votes
2answers
240 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; ...
22
votes
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 ...
0
votes
1answer
88 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 ...
1
vote
4answers
100 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 ...
0
votes
0answers
56 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 ...
1
vote
1answer
71 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 ...
2
votes
0answers
64 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 ...
0
votes
0answers
32 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 ...
0
votes
1answer
47 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 ...
0
votes
2answers
106 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 ...
0
votes
2answers
83 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 (...
1
vote
1answer
41 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 ...
0
votes
1answer
74 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: ...
0
votes
1answer
52 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 ...
1
vote
1answer
71 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 ...
1
vote
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 ...
0
votes
1answer
32 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 ...
0
votes
2answers
112 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 ...
1
vote
0answers
51 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. ...
1
vote
1answer
37 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 ...
0
votes
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: <...
1
vote
1answer
46 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?
0
votes
3answers
132 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,...
0
votes
1answer
52 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: ...