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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Timer activated by Reed on AC solenoid

Let me start by saying thank you for taking the time to read this - I really appreciate it! To the point: I am trying to create a 2-digit timer that resets and then starts at the activation of an ...
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889 views

Master-slave timing on ARM Cortex-M0

I have set up a slave timer that starts counting when the master timer is enabled. I want to know if the slave starts counting when the master timer receives a valid edge (my configuration is count ...
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1answer
33 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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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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196 views

STM32L1 Discovery Kit 5MHz PWM Generation

I have been using the STM32L1 Discovery Kit with the STM32L152RCT6 MCU. A project that I am working on requires me to output two PWM signals. One of these is a 100KHz square wave and the other is ...
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298 views

ATtiny85, timer 1B does not work if COM1A1|COM1A0==0

I read the datasheet, and checked http://www.avrfreaks.net forum, but I cannot understand why on an ATtiny85: ...
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1answer
766 views

Achieving 32-bit timer resolution

I am trying to achieve 32-bit resolution using 16-bit timer on STM32F103. I found that ST provides an application note AN2592, however, I have two concerns regarding it: 1) I don't understand why are ...
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1answer
4k views

STM32F4 HAL - PWM Phase shifting channels on the same timer

I've configured my STM32F407VG (STM32F4Discovery) TIM4 timer using the following code: ...
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2answers
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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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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75 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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1answer
75 views

Need help to identify this timer

This device is installed in our electrical panel which act as a timer to control the on/off operation for our LED billboard outside my office. I searched around the device for the brand and model it ...
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48 views

IoT wireless solenoid circuit

I am a Newbie and I do not have a lot of expirience. The circuit has been put together from pieces I have found on the internet. My goal is to develop a reliable wireless solenoid circuit to water my ...
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1answer
47 views

MSP430F2272: Timer B Capture giving shorter measures than the real ones

I'm using: CCS V8 MSP430F2272 DSO-x 2024A Agilent oscilloscope Trying to measure elapsed time between pulses with Timer B, Capture Mode. My square wave source is at 50 kHz and my timer_b clock at 1 ...
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38 views

Simple coountdown timer IC that is independant of supply voltage

I'm designing a shutdown circuit that switches off a SMPS regulator after a 10 second time interval. This is a battery powered application and the battery voltage could be anywhere between 7-15V. I'...
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52 views

556 circuit not working

I just got my 556 timers and I wired it up just like the 555 but now: it flashes one HighTime and stays off then... I used this calculator and basic diagram: http://www.ohmslawcalculator.com/555-...
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196 views

STM32F407 - how do I run one motor at a time? Why do they ignore delays..?

I'm a newbie. I'm using an STM32F407 discovery board, and I want to control 6 stepper motors using PWM, especially OPM(One Pulse Mode). Till now I've made 3 stepper motors work using Timer 8 (CH1, ...
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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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1answer
54 views

Simple residential blower control

Basic question is: Is it permissable / safe to connect a $10 plug in timer relay with potential for backfeed from a second source? 20 watt fan being switched. This is a SIMPLE question, compared to ...
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1answer
57 views

Problems with dividing a clock with 2 command bits

I am trying to make a clock divider commanded by 2 bits :DTPS. For instance if DTPS is: "00" we get the clock as output(2^0) "01" we divide the clock by 2 (2^1) "10" we divide the clock by 4 (2^2) "...
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191 views

STM32F4 OC Clock Jitter

I am using STM32CubeMX to configure an STM32F4 to output a clock signal using Timer 3, Channel 4 on PC9. I have read in the datasheet PLL section that jitter shouldn't be more than 15ps RMS but I am ...
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172 views

How to vary the range of a potentiometer…is this even possible?

I am a total noob so apologize if this doesn't belong here but I haven't had any luck finding an answer to this... I have a simple circuit with two 555 timers...similar to an Atari Punk Console. I ...
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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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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
543 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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0answers
840 views

STM32F107 generate PPM signal

I need generate special signal PPM for my rc toys, for example: I'll use stm32F107 and I would use a timer which will be a resolution of 0.1us. The web is a lot of examples to generate the PWM signal ...
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588 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 ...
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46 views

Only allowing input after x amount of time

I've been given a problem to solve - When the input is high (sensor), a timer should start which outputs high for 10 minutes (camera active). After 30 minutes, if the input is high, the process ...
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0answers
111 views

pic timer triggers twice

I'm programming a pic18f24k50 using Timer0 to trigger an interrupt every 5ms. I'm handling USB interrupts too Here is the code where I init the timer: ...
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0answers
300 views

PIC12F simulator: Why isn't the oscillator running?

I have written firmware for a PIC12LF1572 that I am testing in the MPLAB X simulator. The program runs and correctly responds to stimuli, except when it needs to wait for a timer interrupt. After a ...
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0answers
59 views

Circuit that takes input signal and controls led

I am trying to design a circuit that compares a recorded signal to a stock signal. If they are not similar it then inputs a signal into a circuit which will change the pulse of the led to stimulate a ...
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1answer
498 views

Using a diode or resistor, to supply minimal voltage to LED Driver (Help!)

I'm using a dual 60W LED multi-chip pendant lighting (a.k.a. "high bay" pendant light with two 60W LED chips). This light is using an RGB driver (one per multi-chip) that has a remote control to ...
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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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49 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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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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1answer
61 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
47 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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2answers
68 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
21 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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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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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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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 ...
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1answer
44 views

Will the choice of prescaler and period while configuring a timer influence the MCU load and power consumption?

Let us say we want to configure a 16-bit timer to generate an interrupt every 1 second with a clock running at 8 MHz. We can use several pair of values for the period and prescaler. Let us take the ...
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36 views

Calling a function that uses HW_Delay inside timer interrupt

I have the following timer interrupt configuration ...
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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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86 views

PIC timer1 interrupt never occurs

I am trying to use timer1 interrupt on PIC18F26K83. I use Micro C as compiler. So I set my timer for 30 ms and after that 30 ms, it is supposed to enter an interrupt and light the LED. But it never ...
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23 views

How is trigger initially higher than vcc/3 in 555 monostable timer?

I get that the trigger must be lower than vcc/3 in order for the comparator to show '1'. But initially how is the trigger higher than vcc/3? In some text it says trigger is initially vcc and so ...
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1answer
45 views

How to make 555 timer output fall

I am using a 555 timer in the monostable configuration, which means that when I send a pulse to the trigger pin, the falling edge will make the 555 generate a high pulse on the output for some time. ...
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1answer
27 views

touch switch time problem

I was looking for a way to make a touch touch switch and i found this circuit on the internet but the problem is , it goes off automatically after few seconds is there any way that i can control it ...
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1answer
39 views

monostable 555 timer - buzzer motor and pulsing

I need this circuit to pulse an LED while running a buzzer motor for an adjustable period RV1 and C1 should give me 1 - 5s of pulse, while RV2 and C2 should adjust the LED ramp times The LED will be ...