AVR is a 8- and 32-bit microcontroller core developed by Atmel. AVR was chosen as microcontroller for the popular Arduino SBCs.

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How can I connect a photo diode to a avr as a round meter? [on hold]

How can I connect a photo diode to an avr as a round meter? please give your answer in detail
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1answer
64 views

Problems Re-Flashing ATtiny85 After Setting prescale to 0x00

After flashing the ATtiny85 with code including setting the clock prescale to 0x00 (in code, not flashing the fuse), the next time I try and flash I get the following errors preventing me from doing ...
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1answer
45 views

How to Identify faulty bus pins on LCD?

I've soldered 14 pins on the back of my LCD and connected to an AVR Microcontroller. The LCD powers on correctly and contrast is set correctly but I'm having trouble sending software initialization to ...
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1answer
37 views

What is each pin's output voltage of an ATmega328P?

I would like to operate an ATmega328P in 3.3V supply alongside some other 3.3V non-5V-tolerant-peripherals. I looked up in the datasheet but I couldn't find an answer as to what is the output voltage ...
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1answer
54 views

AVR SPI slave with interrupt

For a project I want to have two microcontrollers talk to each other via an SPI interface. I wrote the following code for the slave: ...
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1answer
28 views

AVR USART OUTPUT almost similar as input

My output is different from my input when I try to read it from my Hercules terminal. Could this be from a bad UART initialization? Inputs : | á, 1, 123 Outputs:|a, ±, ±²³ Code: ...
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1answer
71 views

Replacing BJTs with power MOSFET

I have 2 x 2N2222 BJTs powering 2 relays of 200mA each. I am using 2 output pins with 500ohm resistors to power the transistors. After powering it the circuit not working well, while replacing the ...
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0answers
386 views

What are free RS-232 terminal programs? [migrated]

I've read signals from an AVR in university, but I forgot what software I was using. I can't seem to find any on google. Maybe I am not looking right. What are some free UART software for AVRs? I ...
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1answer
38 views

Is there any online or free to download (for Windows 7) AVR simulators? [closed]

I'm currently using CodeVision AVR to write a code. Let's say I have a compiled HEX file and I'd like to try it running on a virtual processor (ATtiny861A). Google gives me some results but I'd ...
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1answer
25 views

AVR reprogramming in circuit wirelessly

What are my options when it comes to reprogramming an AVR in-circuit? The new program will be received via a wireless connection, so it will need to be stored in some temporary memory container. I ...
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24 views

AVRDUDE Set lock bits to avoid reading flash through SPI (ATmega328P)

I want to avoid reading my flash through SPI. From the ATMEL datasheet and posts in the internet, it sounds that I have to set LB1=0, LB2=0. When I read the default lock bit from my AVR with: ...
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36 views

Using AVR with Waveshare capacitive touch keypad

I picked up a Waveshare capacitive touch keypad and am trying to get it to work with a ATmega1284P. I have the KEY1 pin connected to PB2 and the LOAD pin connected to PB3. I also have a HD44780 LCD ...
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1answer
47 views

AVR ISP-Programing LEDs SCK

I'm using a Attiny45 microcontroller and USBtinyISP as my programer, and this is the first time I need to hook stuff up (in this case just LEDs, but eventually I'll want to conect a raspberry pi) to ...
2
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1answer
90 views

BJT base resistor

I read this post: Which resistor for NPN transistor base? But I still cannot understand the base resistor calculation. I need the transistor to be a switch to 5V 200mA relay. The base will get its ...
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2answers
124 views

Transistor to run relay

In addition to my last post I have more information and details. I want to run 240V Relay (5V Coil) from my AVR chip (ATmega328P). My EMR relay takes up to 200mA on it peak. I have 2N2222 ...
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3answers
75 views

AVcc, and capacitor, using ADC

I am using Atmega328P to read temperature from LM35 and display it on the LCD (along with few several things it does). I want to understand the capacitor and connections for the AVR itself and AVcc. ...
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3answers
56 views

AVRDUDE with buring settings of AVR Studio

I make my own electronic boards often with an Atmel ATmega328P. I used AVR Studio for programming. Now I tried to make the same settings with avrdude and it looks, that they are not really ...
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2answers
108 views

A Beginner's Question: 32 bit vs 8 Bit [closed]

I am in the process of getting started with electronics, and I have come to a crossroads. Being a complete beginner, should I start with 32 bit microcontrollers (specifically Atmel's UC3 series), or 8 ...
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73 views

How to use the output of IAR Embedded Workbench compiler for proteus?

The CodeVision compiler and Bascom compiler generate one file with *.coff And *.obj format that we can Debug our program by these files in the proteus program. is there the same file in the IAR ...
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1answer
235 views

What does the 'A' letter in Atmel's ATtiny devices mean?

I have both on stock: ATtiny861A-SU and ATtiny861-20SU. But I can not find out any difference between them except 'In-System Programmable via SPI Port' available for 'A' version. Could anyone tell ...
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1answer
14 views

ATXMEGA128A4 and bluetooth BTM-331

I have some questions regarding atxmega128a4. I want to use all of its 5 uart modules but my very basic problem is that I do not know what are the pins for RX/TX. I have read in manual but I cannot ...
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60 views

WS2812 with ATtiny5 Microcontroller Code

I'm having problems with driving a single WS2812 driven LED. I'm using a much more compact version of the code here which is basically I just put in the methods I need and put it all into one file ...
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1answer
105 views

My OLED 128x64 0.96 inch(with SSD1306 driver) doesn't work!

I'm working to use of this OLED but I don't know why doesn't it work!? the Schematic of adaptor is this: and this is assembeled project on breadboard: when I check out the pins of SPI of ...
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1answer
71 views

What's the basic difference between ARM, AVR and 8051 microcontroller? [closed]

I've been trying to do a project using Arduino, I need your help to know the basic differences between these. Thank you
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1answer
59 views

Any regulation needed when powering an AVR MCU from USB?

I know that USB PSU's are regulated but does that mean I really don't need anything at all in my circuit to have reliable operation? Now my circuit will be running 24/7 and should be as reliable as ...
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41 views

Why can't I use my AVR programmer with serial functions?

I recently created a project in which I made my own AVR test bed based on the Arduino Uno. I used the ATmega 328P and I have set up all the fuses for the external clock and the Arduino IDE to ...
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72 views

Powering AVR project

I am building new project, which I will power up the water tank heater from my smartphone. I have few safety though I want to ask here to get your opinion. I am going to use AVR to run a relay, that ...
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70 views

PCB voltage and current

I am building new project, which I will power up the water tank heater from my smartphone. I have few safety though I want to ask here to get your opinion.. I am going to use AVR to run a relay, that ...
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2answers
139 views

Choosing the right Relay for the mission

I am building new project, which I will power up the water tank heater from my smartphone. I have few safety though I want to ask here to get your opinion.. I am going to use AVR to run a relay, that ...
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1answer
86 views

Choosing a transistor to Relay

I am building new project, which I will power up the water tank heater from my smartphone. I have few safety though I want to ask here to get your opinion. I am going to use AVR to run a relay, that ...
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1answer
93 views

Safely driving a SG90 servo with AVR PWM

I've read that servos tend to draw anywhere from 10mA to 200mA. Is there a standard configuration to drive servos using MCUs without directly connecting them to the output pins of the controller? Or ...
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2answers
804 views

Firmware protection on AVR and PIC controllers

Can someone extract the HEX file that I burn in a microcontroller I provide them? If that is possible, how can someone ensure that their code is secured in embedded systems? In the case of PIC and ...
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1answer
63 views

Prevent full startup when only battery backup applied

I have an ATMega328 running firmware that goes to sleep when main 5V power is removed and runs on a 3V backup battery instead. While in sleep, the watchdog timer wakes it up occasionally to keep a ...
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1answer
79 views

HD44780 initialization for 4-bit mode?

I have successfully implemented the I2C protocol necessary to communicate with the device, but I am absolutely stumped on the initialization sequence to get it to work. I have tried countless ...
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1answer
82 views

Watchdog timer not being called in sleep mode

On an ATMega328p, I'm trying to setup a program that counts 1 second intervals via the watchdog timer, even when the chip is in sleep mode. A button interrupt puts the chip into sleep mode. The ...
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99 views

PIR motion detector and ATmega8

I am trying to use motion detector with my Atmega8. I have this part which produces LOW an the ALARM pin when it senses motion. I tried to set 1 output pin as ADC on the ATmega and see when it ...
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2answers
34 views

Not getting input on STK600 with ATmega8515

I recently had a written exam for a class and one of the questions was to write a program for the ATmega8515. I wrote down this: ...
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2answers
90 views

Is it safe for micro to switch pins from input to output in a loop?

I'm trying to make use of a keypad that I took out of a phone which has 3 columns and 4 rows. I've traced out the schematic on its PCB and figured out a way to drive it that I think might work, but ...
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1answer
83 views

16x2 LCD not working with ATmega 8

Below program is written in AVR studio. Connections: PORTD pins 0 to 7 are connected to data lines of LCD i.e. DB0 to DB7 respectively, PORTB.1 connected to RS, PORTB.2 connected to R/W and PORTB.3 ...
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1answer
74 views

What is the difference between Timer0 and Timer2 in AVR

I'm using ATmega32. This two timers looks very similar. What is a difference between them? When should I use Timer0, and when Timer2?
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1answer
67 views

I2C communication with AVR - how to let the lines “float”?

I am trying to implement I2C using an AVR controller without the designated internal TWI registers. The I2C protocol requires that the Master device drives the SDA and SCL lines to begin with in ...
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1answer
41 views

Fixing ATtiny45 Clocksource

I accidently changed my ATtiny45 clock source to 128khz . After that I can't program it . I tried avrdude in terminal mode but it doesn't work . ...
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1answer
95 views

Button to start LED, release jump again

I am trying to do the following small project: Master MCU have 2 buttons - PINC0 and PINC1 PINC0 will count the clicks PINC1 will blink the LED n times (n=counter) and send n to the SLAVE MCU The ...
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2answers
112 views

Why is OCR1B values are not stored?

I have following program to control two servo motors: ...
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1answer
35 views

Controlling a Link Sprite camera through an AVR - how to get the data to a PC? [closed]

I have a Link Sprite camera through which I intend to take image captures and store them into an EEPROM. Later, I want to extract the data from the EEPROM and display the image on a PC. What are my ...
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1answer
69 views

How to store array of values in EEPROM of ATmega16 and then read it in sequence

I have this program in which I can store a single value in EEPROM. Can I store an array of values in EEPROM? How? ...
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1answer
67 views

Saving the last value used in an ISR

I am using a level-triggered interrupt. During the interrupt OCR1A increases and the servo moves. I want to save each value of OCR1A when the pin returns to its previous level. So far I have only been ...
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1answer
75 views

How to increment OCR1A value in ATmega16 through hardware?

For my project I am controlling servo motors through ATmega16 micro controller. The OCR1A determines the position of motor. I want to increment the OCR1A value through a hardware switch. I tried ...
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47 views

AVR: check controller health?

I'm very new to programming controllers and while reading a book I've been building a circuit that looks like has killed my controller. Thats the output from avrdude and MKII clone programmer: ...
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2answers
130 views

How can I wake up an ATtiny84 microcontroller at specific time of the day?

I am trying to create an alarm that wakes up at a certain time and does a series of instructions. To set the times that it wakes up, I am going to use the headphone of an Android device to send ...