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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48 views

LM555 no output even when trigger is high or low

Good Day! I have been banging my head on the desk because I am failing to get the attached circuit work after PCB assembly. I am using Circuit Wizard and my circuit diagram and PCB simulation works ...
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1answer
34 views

STM32 Encoder Mode, CNT don't count

I'm using STM32L476RT. I've got encoders based on TLE4946-2K. I can't get it to work. I'm attaching my code and config below. I'm kind of stuck at this point - I tried to lower the voltage by divide ...
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1answer
1k views

What does TIM_OCMode do on STM32F4?

I'm making locked antiphase drive for motor control on STM32F4 board. Im configuring Timer4's 4 channels to be in pairs, ch2 inverse of ch1 and ch4 inverse of ch3. Each pair will control its own motor....
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29 views

STM32 - Configure Output Compare Registers on the Fly

since this is my first, feel free to give newbie a feedback :) I have a following setup with my STM32 Nucleo (simplified, ignore the HW behind): a) one input signal acquisition (Square wave, consider ...
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20 views

Timer not having output after initial powering

DGM TIMER RELAY BOARD 12V 1S-1HR Time Delay ON or OFF 12V Relay Board with jumper settings and 8 Time Ranges selectable from 0.1s up to 1 hour accessing loads 250VAC 10A or 30VDC 10A I believed this ...
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4answers
18k views

How to wire this delay relay switch

Hello I recently bought this item at ebay and I am not sure how I should wire this. I will power it with a 9 volt battery and the relay will power a pump, this is how they at ebay show how I should ...
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1answer
39 views

STM32F4 get timer to work >2MHz

I have nucleo-401RE (STM32F401) board. I am trying to setup a timer (TIM4) to work above 2MHz (on bare-metal code). Per the timer settings below I am supposed to get 10.5MHz. On scope, I am getting ...
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60 views

stm32 create a microsecond timer

I'm relatively new to stm32 stuff and i wanna get data from some rotary encoder, and i'm using interrupts to do so, i'm using a usb cable to send data from MCU(stm32f103c8t6) to my pc device and i ...
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33 views

STM32 Timer Discrete Jitter

I'm using a STM32F746 running at 200MHz. A timer (tim2) is counting up at 100MHz and triggers an update interrupt with the following simplified ISR that writes a pattern to GPIOB ...
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0answers
17 views

EFM32ZG110F32 Timer PWM with DMA - slow to update

I have a project where I am trying to drive some Addressable RGB LEDs which require a high-frequency PWM signal (800kHz) with a duty cycle of either 33% or 67%. I have started from the following ...
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4answers
14k views

High resolution system timer in STM32

I have some software running on an STM32F103 (I'd also like to be able to use the F4) where I'd like to be able to 'timestamp' events (such as interrupts on external pins) to the nearest microsecond (...
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1answer
650 views

power on power off pulses to two seperate controllers

I would like to request a circuit where a 500 ms pulse is sent to one rail when 12 volt power is supplied and another 500 ms pulse is sent to a different rail when power is turned off. 555 is the way ...
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2answers
861 views

STM32 Input capture PWM frequency measurement problem using HAL

I'm trying to measure time passed between two external interrupts generated by rising edges of a PWM signal (generated using a IC 555 timer). Point is to determine the frequency of the signal. I'm ...
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2answers
189 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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2answers
423 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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1answer
177 views

NE555 Circuit stops working after random time

i finished my NE555 circuit and created some pcbs. After a few attempts i could get the circuit working, and tested it successfully. I placed my circuit between a 12V 1.5Hz square wave signal and a ...
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3answers
134 views

How to automatically turn off a Fan after a fixed amount of time?

I have an exhaust fan in my bathroom (used for removing the steam generated by a hot bath). Currently, it can be turned on and off by a regular switch. My goal: Exhaust fan should automatically turn-...
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1answer
444 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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2answers
49 views

How to bypass continuous input on Trigger pin of 555 IC after some time working in Mono-Stable/ One shot version?

I configured the 555 IC such that it gives the output pulse for 3 Seconds (Approx.) as soon as there is input on trigger pin, but my project requirement is; even if there is input continuously on ...
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1answer
57 views

How can I get rid of interference between two signals in this timing circuit?

I have designed a small circuit to perform the following functional purpose as illustrated below. The circuit takes a PWM signal as input from a microcontroller and outputs two smaller pulses (ideally ...
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1answer
207 views

STM32 DAC Trigger

I am Trying to use the DAC output on my STM32L053R8 NUCLEO Board. I generate the corresponding Sin-Wave values to set the DAC Values like this. ...
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1answer
180 views

Open and Close Circuit automatically (Automate Push Button)

I have a simple circuit board with a push button on it. I just want to automate the pressing action every 0.2 sec or so. The push button has two terminals underneath and I understand that I should ...
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1answer
231 views

AC dimming with STM32 timers

I'm using an STM32 for AC dimming, for which I use a GPIO output (or timer channel out) to drive a triac, whenever I get a zero crossing detection (rising edge). Is there a way to solve this only ...
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1answer
36 views

Delay timer circuit

I want to design a timer circuit to turn on a MOSFET based switch for 15 seconds. I did research on the internet but couldn't find any help. The idea is that if we give a voltage pulse on the gate of ...
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1answer
93 views

555 timer not working in monostable mode

I am a newbie electronics learner and trying my hands on 555 timer to get it running in the monostable mode. Am trying the circuit as in the attached diagram. I am just unable to get the LED blink. I ...
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1answer
30 views

STM32F4 Discovery ADC trigger using Timer 2 and DMA | CMSIS Core

I am working with a very old problem which is to convert ADC and send to UART via DMA. I am stuck at making the correct sampling time. What I had done so far is to configure TIMER2 and ADC. I Used ...
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1answer
191 views

Using SysTick_Handler in mbed LPC1768 project

I'm trying to use SysTick_Handler in a project which uses the mbed libraries and RTOS, however on compilation, the following error is returned: ...
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1answer
421 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
39 views

How does this specific boost converter work?

So I found this Geiger counter at https://mightyohm.com/blog/products/geiger-counter/. You can also find the detailed electronic schematics there. I tried to figure out how this apparatus works, but I'...
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1answer
799 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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4answers
15k views

How to turn a switch on/off repeatedly in 1 minute intervals?

I have a light bulb plugged into an outlet and I need to be able to turn it on and off again and again in 1 minute intervals for a period of 10 hours per day (a total of around 600 on/off events per ...
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1answer
114 views

Configuring Atmega32 timer using the oscillator without prescaling gives wrong delay time

I am using AVR atmega32 microcontroller. The code below is supposed to toggle the LED connected to PORTD. The frequency of the oscillator connected to the ...
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1answer
130 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
128 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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2answers
121 views

pic16f877a problem in timers with proteus simulation

I used PIC16f877A at proteus to do timer interrupt. The code is pretty simple it has nothing to do rather than setting the timer1 registers , the while(1) loop is ...
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2answers
86 views

Super low duty cycle circuit

I am looking for a way to recharge some glow in the dark paint in a way that isn't noticeable to others. My idea is to use a very fast pulse of light from a bunch of UV LEDs every few seconds, but ...
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2answers
348 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 ...
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2answers
63 views

Context Switch in C in 32-Bit MCU

I am trying to understand the concept of 'Context switch' in reference to C-language and 32-bit MCUs. For example if I am programming STM32F407 MCU in C-language using STM32CubeIDE and I want to ...
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1answer
18 views

STM8 alarm firing shortly after resetting time

I'm using an STM8L151F3 with the SPL, compiled with SDCC. I'm trying to generate an alarm interrupt after n seconds, then another after m seconds. To do that, I reset the time to 0, then set the alarm ...
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3answers
303 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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0answers
32 views

Will this “off delay” circuit work if a continuous trigger is applied to pin 2?

This is an off delay circuit using a 555 timer. I want to know if this can be used even if the trigger signal is continuous. If, not what modification is needed?
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1answer
123 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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0answers
56 views

Can't seem to properly generate a delay via timer

So I am trying to create a delay using a timer but doesn't seem like it's working as expected. With a clock of 16MHz and a prescaler of 1, it should take 10us to reach a count of 160 (unless I did ...
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6answers
158 views

Generating a delay on the order of microseconds (timer vs HAL_Delay())

So I am using an nRF24 radio module and I probably need a 10us delay after enabling chip select. But the thing is I can't use HAL_Delay() since the least it ...
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1answer
371 views

How to disable timer on MSP430?

I am new to the TI MSP430G2553. I would like to send a PWM signal like in this picture: (Image source: Adafruit - Understanding Infrared Signals) However I can't do that, because I don't know how to ...
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2answers
80 views

DIY Pierce Oscillator not working

I'm building a simple pierce oscillator for fun and trying to read the frequency using an arduino uno and the freqcount.h library (I don't have an oscilloscope). However, I'm consistently getting a ...
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0answers
64 views

STM32 TIM2 changing prescaler in IRQ handler works strangely

I am trying to change a prescaler in the timer interrupt handler, and I expected the new value would become active for the very next timer delay. I mean that after the handler exits, the timer will ...
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2answers
6k views

Is there a way to control the PWM duty cycle of a 555 timer without using a variable resistor?

I need to control the duty cycle of a Pulse Width Modulation (PWM) circuit from a DC voltage input. To do this, I've been looking into 555-timer circuits - but every circuit I've come across involves ...
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1answer
25 views

Advice on setting up sensor switch

Hi I would like to fit a (motion sensor/IR sensor) sensor switch to a machine in my catering van. The machine is a 12v machine. I would like to start the machine using the sensor switch and would like ...
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1answer
38 views

Bug and Best Practices for Interrupt Handling/Organization

I've read a few documents on best practices for interrupt handling and thought I was doing things correctly, ensuring the variable set in the ISR was declared volatile. In my code the interrupt ...

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