Questions tagged [reset]

The reset line on a computer or other digital circuit places the circuit in a well defined initial state. Most microcontrollers have a built-in power-up reset to start the CPU executing code and may also have external resets and watchdog timers to help recover from unexpected events.

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2answers
750 views

Using a 3.3V MCU (Arm) to control reset pin of a 5V MCU (AVR) without a level shifter [duplicate]

On my PCB I'm trying to avoid a level shifter chip. So is it possible to connect my ARM CPU's GPIO pin (which runs at 3.3V) to the reset pin of the AVR chip? I was thinking of setting the ARM GPIO ...
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1answer
2k views

Reset 555 timer when trigger switch is released

I have a simple 5 second Monostable 555 Timer circuit. Trigger Pin (#2) is connected to a momentary push switch. When it is pressed, the timer is started and LED stays on for 5 seconds. What I want ...
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1answer
451 views

High impedance op-amp using guard ring to drive a shield

http://imgur.com/a/GSALb http://imgur.com/gallery/9QrWO So I'm looking at the first picture and I'm trying to figure out now the whole shielding part of the circuit works right now. The second image ...
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1answer
340 views

Atmel SAMC21 microcontroller unwanted resets

I am using an ATMEL SAMC21 MCU on an ebike project. The MCU is involuntarily resetting every 30s to 1min. This causes a problem as it's controlling the bike in real time, giving noticeable gaps in ...
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Can I wake ESP8266 with photoresistor like in this schematic?

I want to wake ESP8266 when the light turns on, send information to the server, go to deep-sleep for a few seconds and then send the information again and keep doing that. If the server stops ...
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2answers
286 views

How to make use of 'Power ON Reset' while there is noise in Power?

I'm using Nuc240LE3AE(Cortex M0) to run a code that is developed. I want to run the code on startup for which (POR)Power On Reset facility is used. Normally this is Enabled in the Micro-controller and ...
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1answer
727 views

How do I extend the output (high) time of my circuit (retriggerable)?

I need help with the design of a timer delay circuit for the output of a sensor circuit which can keep the output HIGH for an adjustable time range (about 1 to 10 min), after the digital output of the ...
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1answer
111 views

May a warm reset by pulling down the reset pin of the SoC cause the file system corrupts?

In my embedded Linux system, I made a hardware switch to pull down the reset pin of the SoC(TI DM365). When the system is running, I can push the button to reboot the system. I want to know whether ...
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1answer
693 views

Why is de-assertion of an asychronous reset a problem compared to its assertion?

"The biggest problem with asynchronous resets is that they are asynchronous, both at the assertion and at the de-assertion of the reset. The assertion is a non issue, the de-assertion is the issue. If ...
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2answers
560 views

Can I use xilinx PLL's locked signal as a reset?

I'd like to make reset signal. now I'm using the xilinx pll and I found that LOCKED_OUT signal. can I use that LOCKED_OUT signal as reset my fpga? the follow is some example for my idea of question. <...
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3answers
627 views

Generate Short negative pulse from an open collector output?

Ive been teaching myself as I go so please forgive me for any errors. I need the output of an open collector output (goes to ground when active) to henerate a short negative pulse to reset the counter ...
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1answer
2k views

STM32F4 doesn't boot after reset and enables read out protection

Sometimes my STM32F4 board doesn't boot after a power-off, power-on reset. All voltages are fine, but the code does not execute. What is interesting, when I connect to the board with ST-link utility, ...
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2answers
1k views

How to add reset functionality to a master-slave D-type flip-flop?

I'm trying to implement a shift register and therefore need values to be stored on the downwards edge of the clock signal (otherwise the whole register just sets to the input), so I am using a master-...
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2answers
9k views

Circuit Diagram for a D Flip-Flop with a reset switch?

I have created the following D Flip-Flop, which works as expected. I am now trying to implement an asynchronous reset to it. How can I edit my circuit so that when the button is pressed, Q is set to 0 ...
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1answer
1k views

Arduino Uno-style Reset Circuit

I recently took an oscilloscope to a reset circuit on a new board I am working on (derivative of WildFire). Nothing earth shattering here, U6 is an Atmel ATMega1284P (VCC=5V), and U8 is an FTDI FT231X ...
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3answers
6k views

STM32 reset not work

Background: 1.5% of products which use STM32F107 didn't work after using 3 months; Lithium battery is the power supply source. The products were used in car. This phenomenon suddenly occured ...
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2answers
528 views

Atmega328p reset not working

I have 3 devices on SPI: Atmega328P, ZM5202 and flash with CS. When I connect Reset of Atmega to GND I cannot talk with other ZM5202. And then I am reading id of avr also. When avr programming: AVR ...
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3answers
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What is the function of this diode in arduino uno(between +5V and reset)

I am doing my own avr dev board using atmege32a and basically I am looking into Arduino uno board design and try to mimic the common parts for best practices like for example power and other stuff I ...
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1answer
7k views

STM32F042 failed hardware reset?

Background I am working on a school project where I have designed a prototype PCB with the core being a STM32F042K6T6 microcontroller. I am using the ST-Link from a Nucleo STM32F401RE card to program ...
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3answers
516 views

4024 cmos counter not resetting

In my project, this section is faulty. I'm doing a bit-banging operation with shift registers and I'm trying to make shift register data reset after 15 bits are shifted out from the micro controller. ...
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2answers
321 views

PICkit 3 set MCLR high

I have a PICkit 3 with a "PICkit 44-Pin Demo Board". To get the demo board to function I need to either disable the MCLR (#pragma config MCLRE = OFF) or put a pull ...
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1answer
834 views

Altera FPGA Reset System

I having a hard time understanding the best way to setup a NIOS II system with external code and the resets and clocks. One of the reasons why I'd like to figure this out is the JTAG system really ...
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1answer
536 views

How to solve overflow stack problem problem in proteus?

I'm currently working on a countdown timer project.I used PIC18F452 microcontroller for my project. I compiled the code in mplab and it has succesfully been builtHowever in proteus, the countdown ...
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1answer
2k views

Enable DTR/RESET by software with an ATMega328 MCU

I’m building a project using an ATMega328, and for the serial communication and programming it, I’ve connected a USB CP2102 controller. The problem with atmega328 (and all arduino boards) is that the ...
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3answers
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SRAM isn't blank on powerup, is this normal?

I had finally finished my Z80 memory board, but I was disappointed to see that it wasn't working properly (simple NOP test with the address lines connected to some LEDs) as the counter quickly ...
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2answers
263 views

Step Generator Reset Circuit Alternatives

I'm working (slowly) on a project to build a curve tracer based largely on the Heathkit original (Heathkit Catelogue - IT-1121) and I've come up against an issue in the step generating circuit. The ...
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1answer
520 views

PIC reset on power off

Attached is the block diagram of my circuit. Input is 230 VAC. A SMPS module converts it to 14 VDC. The on board regulator then converts it further to 3.3 V. I have observed that many times when I ...
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2answers
1k views

555 timer bistable circuit problem: default flip-flop state is 'ON' on power reset

The following circuit is a controller for a water pump. It turns the pump on when the reservoir water level drops below the 'L' probe and turns it off when the level reaches the 'H' probe. This ...
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4answers
3k views

Is power cycle reset different from reset pin reset?

I am using custom built arduino uno for a home automation project. Sometimes, the arduino locks up due to electrical noise or sparks in the ac lines. More details here. I tried conducting some ...
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1answer
3k views

How do you restart the MSP430 Launchpad programmatically with Energia?

Can anybody tell me what Energia method I can call to programatically reset the MSP430 Launchpad. Under certain circumstances, I need it to power down and back up again. It needs to shut down power ...
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1answer
93 views

D flip-flop using basic gates + Clear

I'm using Logisim to make basic circuits and they have in-built things such as Counter and D Flip-Flop. The D Flip-Flop looks like this: It however doesn't show how it's made up of the basic gates (...
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1answer
147 views

PIC24 Reset Issue

I am working with the PIC24FV16KM202. I am encountering resets while implementing Dispatch, which is a serial protocol that I'm working on that grew out of a project. The example that I'm working on ...
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1answer
1k views

Best way to control power with MCU gpio pin

This is my circuit. An MCU gpio pin should control the power of another IC. Because the component requires more current than the gpio pin can drive, an N-Channel MOSFET is used. This is IC has no ...
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1answer
476 views

Digital Logic Reset [closed]

Question Too broad apparently.
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2answers
5k views

Do I need to reset my FPGA design after startup?

I usually initialize state registers of my FSMs by specifying an initial value in my VHDL code, so that, I do not require a reset pulse after startup of the configured FPGA. The following example ...
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3answers
277 views

Designing a factory reset switch

I want to add a factory reset onto a PCB design I am working on. Basically, I want it to be a switch (or combination of) that will never be "accidentally" closed and therefore accidentally factory ...
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3answers
4k views

How to protect Reset pin of MCU from ESD strikes?

We have been designing ESD protection circuits for MCU exposed pins. Here comes the reset pin protection: The pin is connected with a ESD suppressor at the connector. The pin is connected in serial ...
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2answers
2k views

Should all traps always be defined?

I've seen two cases now with dsPIC 30F4013 where the controller was resetting due to an undefined trap. Why these traps were getting raised in the first place is still a mystery, but that's not my ...
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3answers
5k views

Purpose of capacitor for MCU reset pin

I know why we need a pull-up resistor on the reset lines, but what is the reason for a capacitor parallel to the reset button? I saw it on Texas Instrument's schematic for MSP430F5529 launchpad.
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Would a reset IC be enough for this many power supplies?

Could you please let me know how many reset ICs I'd need for my board? I'm designing a camera using the IMX225LQR Image Sensor. This sensor requires 3 different input voltages: 1.2v, 1.8v and 3.3v ...
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1answer
896 views

SD Card Reset Issue

I've got an issue where I'm playing around with the SPI commands to get SD card comms working but it seems that if I send something the card doesn't like I get in a condition where it can't reset. ...
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2answers
8k views

Factory Reset a HM-10

I had programmed a HM-10 module to act as iBeacon with my Arduino Uno's serial monitor using the following steps: AT+RENEW Restores factory defaults AT+RESET Reboot HM-10 AT Wait for OK AT+MARJ0x1234 ...
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2answers
751 views

Resetting a microcontroller with a button connected to Vcc

I would like to have a way to reset my PIC by removing power from the chip. My hacker self thinks that the simplest way would be to add a resistor between the output of my LDO and Vcc on the PIC, and ...
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2answers
1k views

Cannot enter programming mode ATMega328p

I'm using an ATMega328p Xplained Mini development board. I was able to program it using Atmel Studio 7, being new to AVR programming I accidentally set the RSTDISBL fuse to 0 (has a default value of 1)...
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2answers
581 views

Should the reset pin on MCP23S17 go to a GPIO?

Most example schematics for Arduino, Raspberry Pi etc have the reset pin tied to GND. If number of GPIOs on the MCU wasn't a problem, would it be beneficial to have the reset of the expander ...
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1answer
9k views

how to reset a memory array in verilog?

I have a memory like this: reg [7:0] memory [1023:0] How should I use a for-loop to reset the memory in verilog? Please give me the code. For example if ...
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1answer
82 views

Minimizing mosfet interactions and overshoots. A case study

I'm back again with another headache of my own creation. It seems I'm constantly learning things the hard way. Straight to the point questions: I've noticed that my reverse voltage protection ...
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2answers
2k views

Reset the configuration of FPGA without reprogramming

I am doing an experiment on Xilinx VC709 board. The experiment involves removing and plugging in the DDR3 RAM while the FPGA is running. But every time I plug back the RAM I have to reprogram the FPGA....
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1answer
153 views

Arduino PCB issue

I have made few different Arduino board which are programmable only via ISP because the Serial communication is giving me this error: Binary sketch size: 3,026 bytes (of a 30,720 byte maximum) ...
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0answers
639 views

Microcontroller on/off circuit in battery power device

I am using the below circuit to turn ON and OFF my load microcontroller circuit in my battery powered device. The max current draw I'm expecting is around 800mA. My logic is like this. For power up ...