Questions tagged [atmega328]

The ATMega328 is the chip that is the heart of the Arduino Uno. It is popular also as a chip to use to create your own board. Since it is available in the through hole version, it can be placed on a breadboard easily for circuits.

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Have I bricked my Arduino Uno? Problems with uploading to board

I can't upload sketches to my Arduino Uno. Have I "bricked" it? What steps can I take to work out what is wrong? What can I do to fix it?
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4answers
10k views

Is my Arduino dead or is it just its processor?

I have a problem with my Arduino. I can't upload any sketches to it (it gives me the error avrdude: verification error; content mismatch), but the LEDs are still blinking. Do you think that the whole ...
12
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2answers
8k views

Put ATmega328 in very deep sleep and listen to serial?

I have investigated the sleeps options of the ATmega328, and read a few articles about it, and I would like to understand if there are more options. So I would like to get as low current as possible, ...
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5answers
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Program an ATMega328P and use it without Arduino board

I'd like to use an ATMega328P for my project, I hope to do it without the arduino board. I know with the Arduino IDE and an Arduino board I can program the microcontroller. However, would it be ...
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2answers
4k views

I got a missignatured ATmega328-PU. How can I fix that?

Sometime in the past, I was burning bootloaders on a fresh batch of four ATmega328-PU using the Arduino IDE (notice there's no P after 328 - it's the slightly cheaper non-picopower version of the MCU, ...
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2answers
2k views

very lightweight low power microcontroller with memory?

I have build a couple of projects using arduino. For a new project I want to log skin surface temperature vs. time (just perhaps a few times per day) and possibly other easy to obtain info such as ...
9
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1answer
2k views

What is the purpose of the I/O pin capacitor on the AVR microcontroller?

What is the purpose of the capacitor on the I/O pins on the ATmega328 (I imagine it's on other AVR microcontrollers as well)? Is it to reduce noise from other parts of the microcontroller?
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1answer
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How do interrupts work on the Arduino Uno and similar boards?

Please explain how interrupts work on the Arduino Uno and related boards using the ATmega328P processor. Boards such as the: Uno Mini Nano Pro Mini Lilypad In particular please discuss: What to use ...
8
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1answer
1k views

Why connect a diode between the reset pin of Arduino and 555 timer?

I am trying to create a watchdog timer using 555 IC and I am following this. I do not understand why a 1N4148 diode is connected between the reset pin of Arduino and the output of the 555 timer. As ...
8
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2answers
2k views

Burning sketch with I2C

Not a pure Arduino question really. I'm actually using a standalone ATmega168. So far I've been using AVR-ISP programmer (working from AVR Studio) to program the chip. After everything is done, the ...
7
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2answers
7k views

What are the implications of running an ATmega328P at 8 MHz and 3.3 V with the Arduino system?

I'm working on a custom arduino that will run at 3.3 V with no regulators or USB chips (for power consumption). I've heard that overclocking the chip at 16 MHz/3.3 V is generally fine, but I'd like ...
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1answer
765 views

Can I program a 3.3v chip on a 5v board?

I bought a Gertboard a while ago, and one of the features it has on-board is an ATMega328 (DIP). However, since the Gertboard is designed for use with the Raspberry Pi, it only operates at 3.3v, so ...
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2answers
8k views

Basic makefile for avr-gcc

I would like to make a makefile for compiling c programs for the arduino. I am somewhat familiar with make but have never used it with avr-gcc. What is the simplest way I could put the commands below ...
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3answers
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ATMega328P-PU and 328P-AU

im planing to make my very own arduino design based on the Arduino PRO mini. I picked this board instead of the UNO mostly because it's way more simpler compared with the UNO since the USB-to-Serial ...
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2answers
1k views

Programming Chinese Arduinos

I have an authentic Arduino UNO, but I didn't want to pay full price for a new one to build semi perminate projects, so I bought a few ATMEGA328P-PU chips off of AliExpress: https://www.aliexpress....
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3answers
4k views

Confusion with ATmega328P and 3.3V/8MHz

Firstly, I have tried to set the bootloader to be 8MHz internal oscillator. I have tried the board setup from here - https://github.com/oshlab/Breadboard-Arduino. And also the breadboard-1-6-x.zip ...
5
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2answers
1k views

Run code once after programming

I'm using EEPROM to store project settings non-volatile. After reuploading the sketch to my board (over SPI via ArduinoISP), the EEPROM is reset to full 0xFFs and I have to manually do a "software ...
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3answers
1k views

Can I use an ATmega328 alone without anything and what is the max voltage I can power the atmega328 with

Okay 2 questions. If I am to replace the Arduino with an ATmega328 programmed with a standard blink on pin 13, is this configuration correct, do I still need oscillators and whatnot? Second question ...
5
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1answer
560 views

Is my ATmega broken, and would replacing it with another break that one, too?

I was communicating between my computer and my Arduino Uno R3 through Bluetooth using this Bluetooth module. The connector I use has a red wire where it connects to GND, and a black wire where it ...
5
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1answer
405 views

Why were Atmel MCUs used for Arduino?

Atmel microcontrollers are not cheap compared to STM and Microchip. Why did Arduino select Atmel MCUs such as atmega328 and atmega2560 on their board out of so many alternatives?
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2answers
3k views

What is the rise time of an output pin of atmega328 changing its state?

I've already searched a lot and didn't found the answer. Also, I don't have an o'scope. Anyone can help me?
5
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1answer
1k views

EEPROM value reverting to 255

When I write '13' to the EEPROM and read it straight after it works correctly. However when I comment out the write part of the code and try to just read the data, the value is no longer 13 as it ...
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2answers
973 views

Arduino Uno as USB to Serial converter (bypass 328p)

I'm trying out computer to computer serial communication using 2 Arduino Unos (both connected to different computers). Right now, I use the Software Serial library, which redirects data from the ...
4
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3answers
902 views

Can I remove soldered atmega328P from arduino board, using hot air gun, without damaging it?

I need to remove atmega328P from arduino board and the best tool what comes up to my mind is a hot air gun. What is the maximum temperature that atmega328P can withstand?
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3answers
3k views

Two function Reset button - long/short press

I am trying to make a circuit using an ATmega328, that has a reset button that behaves like many consumer devices: A short press just restarts the micro-controller A long press (5 seconds?) causes ...
4
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2answers
139 views

Usefulness of measuring 0v using ADC

I'm looking at the datasheet of the ATMega328, and I see the different channels you can select for AD conversion. ADC0..7, ADC8 (temperature), 1.1V (VBG), and lastly 0V (GND). What would be the use ...
4
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2answers
12k views

How to use the analog comparator to determine when an analog pin has reached a certain voltage?

I am trying to find some information on how to use the analog comparator on an Atmega328 to detect when an analog pin has reached a certain voltage (3.16 volts). I cannot find any example code that ...
4
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2answers
114 views

Trouble with Timer 0

I'm taking my first wobbly steps outside the Arduino IDE and I'm not having much success with timers / interrupts. I can set a pin to output and light an LED with registers fine but I cannot for the ...
4
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2answers
677 views

How can I use PWM in power saving mode (ATmega328)?

I fail to use PWM in power saving mode. The output behaves erratically. This should be possible, I guess. The following is a minimal working example: /* MWE: Cannot use PWM in any power saving ...
4
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3answers
102 views

Powering an USB to Serial from USB

I am creating a PCB which is a modification of the Arduino on a breadboard. I am intending to buy an USB to Serial breakout from Adafruit so that I can upload my sketches to the atmega 328 I'll be ...
4
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1answer
94 views

Arduino IDE Based Data Logger - Stops Running

I have created a data logger that writes to a MicroSD on a user defined interval. The data logger also has the ability to use an xBee unit to transmit the data received to a base station. This is ...
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5answers
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nRF24L01+ RF24 library - can send but can't receive

I'm prototyping out a board with temperature, humidity, windspeed sensors, and using an NRF2401+ board to send values to a Raspberry Pi base station that will record the data. Using a Leonardo clone ...
3
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6answers
9k views

Lowest power possible in Arduino

I have googled all around and I know about some tricks to make ATmega328 not being a power hog. I am using Arduino Nano V3.0. However, I didn't find out what is the minimal consumption possible with ...
3
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4answers
148 views

Where in datasheet is the warning about unreliability of reading PINxn?

I use atmega32u4 (but believe it applies to all models). Here is the datasheet. Consider the following C program (I use AVR-GCC 5.4.0): #include <avr/io.h> int main(void) { PORTB |= 1 <&...
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2answers
2k views

Using Arduino as ISP to burn sketch directly to ATmega328 without first installing a bootloader on the ATmega328

Is it possible to take a bare ATmega328 chip, and with an Arduino as ISP, burn a sketch directly to the chip (e.g. not needing a bootloader), or is the bootloader required to run Arduino sketches? I ...
3
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1answer
5k views

Sending serial data in an interrupt

An ATMEGA328-P chip is used with a toggle switch attached to pin 8 and a momentary switch attached to pin 9. My objective is to send the following information over serial: The status of pin 8, every ...
3
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5answers
12k views

SIM800L change default baud rate

I am using an ATmega328P with internal clock (8 MHz) with a SIM800L module. The default baud rate of the SIM800L is 115,200 baud and I can't make them talk to each other correctly. Although I was able ...
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2answers
546 views

Can a timer be used in both CTC and (fast) PWM mode simultaneously?

I would like to generate a sequence of pulses of varying lengths in the range of 0-100us, so that from the start of one pulse to the start of the next there is a delay of 100us. I have set up timer0 ...
3
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2answers
152 views

Barebones 328p, 2xAA vs 3xAA, which will last longer?

So im just running a 328p at 8mhz with the internal oscillator. Datasheet says 1.8 to 5.5v is voltage range. Will 3xAA in series (~4.5v) last longer than 2xAA in series (~3v), assuming all batteries ...
3
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2answers
646 views

WORDS in ATmega328 datasheet note

I came across something strange while reading the datasheet for the microcontroller in the Arduino Uno board. It is the (8) note in pg.296-297 of this datasheet: what does WORDS mean in that context?
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1answer
374 views

Which of the clock sources are actually internal to the ATmega328P?

I am trying to determine exactly what all of the fuse settings correspond to on the ATmega328P. The options for the CKSEL bits are: 1111-1000: Low Power Crystal Oscillator 0111-0110: Full Swing ...
3
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1answer
352 views

ctc mode on atmega 328

I'm trying to use CTC mode on Arduino 1 but I have the following problem. I need to generate an interrupt on threshold B and A and I have set the prescaler to 1 since I want to generate interrupt A at ...
3
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1answer
3k views

Reset fuses on atmega328p using Arduino

I bought a few atmega328p chips but unfortunately they came with the Arduino bootloader and they are set to use the external clock. I want to reset their fuses using avrdude so I can use the internal ...
3
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2answers
369 views

7805 powered Atmega328 Stops working when input of 7805 exceeds 7volts

I am developing a circuit with atmega328, the MCU is powered by a LM7805. The input of 7805 is given by a variable supply. Till the input of 7805 is 7volts, the output voltage is 4.9volts and current ...
3
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1answer
46 views

Cheapest way to change digital output source

Powering at 5 volts, atmega328 output ~4.7 volts. I need to output between 12 and 24 volts @ 2 amp. I'm currently using relay but they are costly. Is there a way to do it with transistors or any thing ...
3
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1answer
2k views

Using an Arduino board to program an AVR

I think the arduino board is awesome. Though I'm not interested in the library and IDE at all... Is there a way, to use an AVR 328p, as you normally would, on an arduino board? I like how arduino's ...
3
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2answers
864 views

Timer2 “Clear OC2B on Compare Match” not working as expected in CTC mode

This is a follow up to my previous question. I have Timer2 in CTC mode, with TOP=OCR2A set to 150 (with a prescaler of 8, giving a 75us timing interval). The datasheet states that setting COM2B1 to ...
3
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2answers
2k views

Atmega328P-PU: Programmer is not responding

Few days ago, I built my own custom Arduino on the breadboard. It is built according to tutorial on http://www.crash-bang.com/resource/breadboard-arduino/. The Atmega328P-PU is already burned with the ...
2
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4answers
6k views

Arduino 16 MHz with only 3.3V?

Now I have these Arduino Pro Mini from Sparkfun. They are the latest version that I know (yeah, it's the one that have those horrible misaligned pins). Now they are designed around the ATmega328P and ...
2
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6answers
250 views

Should I use an Arduino or not?

I am building an electronic gadget eventually to sell. I think the Atmega IC is used in the arduino and could this be programmed as easily as the arduino? I'm wondering if I can use the chip and buy ...