Questions tagged [atmega2560]

Low-power 8-bit AVR microcontroller with 256kB flash.

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5
votes
4answers
2k views

Will an ATmega2560 board be faster than a Uno for hard real-time data logging?

I am designing a hard real-time data logger. The Uno is a bit marginal in processing speed. a) Would it be faster if I changed to an ATmega2560? b) On the datasheet, ATMEGA2560 has 135 instructions; ...
3
votes
4answers
2k views

If else statement not mutually exclusive?

When I'm running some test on my encoder motors using the following provided code by Makeblock, it appears that the if..else.. statement is not mutually exclusive ie. I can control Encoder_1 and ...
3
votes
1answer
436 views

Bootloader and Boards Definition for Atmega2560V-8AU at 8 MHz / 3.3v

I am working on a home made project,where i am using Atmega2560V-8AU (note the suffix, this part has an 8 MHz maximum clock rate) as my main controller, supplying 3.3V to this chip. I want this ...
3
votes
0answers
75 views

Adafruit_LEDBackpack library interfering with analog input reading

I'm trying to do something I think would be simple. I'd like to read the input of a electret microphone board and update the Adafruit 24-segment LED Bar Graph. I got each individual item working ...
3
votes
1answer
224 views

How to wake up Arduino with an rtc?

I am doing a data logger with an Arduino Mega2560 and I want to use a code to make it sleep when no measure is needed and wake it up with an RTC when time comes. The reason I want this is because I ...
2
votes
2answers
202 views

ADC register always returning high

Regardless of whatever voltage at A0, the software is always returning high (1023) volatile unsigned char* ADmux = (unsigned char*) 0x7C; volatile unsigned char* ADCSRa = (unsigned char*) 0x7A; ...
2
votes
2answers
375 views

Is there an ICRn CTC mode interrupt vector?

I can use the CTC waveform generation mode to loop to OCRnA and trigger the corresponding TIMER1_COMPA_vect interrupt. // CTC mode TCCR1A &= ~(1 << WGM10); TCCR1A &= ~(1 << WGM11);...
2
votes
2answers
99 views

Arduino Uno lag in simple loop

I have a simple Arduino sketch which I have been playing with on my Uno. The idea is simple, the user turns a potentiate (pin A2), when they pass a certain threshold a LED is turned on (pin 7). Here ...
2
votes
1answer
698 views

Trying to run Timer1 in ATmega2560 with assembly

I have a slight problem with Timer1 in arduino (ATmega2560) while coding it in assembly. I try to run the Timer1 in CTC mode - I configure everything well in my opinion, but the TCNT1 just doesn't ...
2
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2answers
1k views

Arduino MEGA2560 Standalone

I had an Arduino UNO (ATmega168) standalone working, but I need more pins, and I decided to use the ATmega2560, I was searching for some schematics, and none of them shown an ATmega2560 standalone, ...
2
votes
1answer
145 views

I2C communication between arduino and raspberry pi breaks under stress for unclear reasons. Why?

I am having a behavior I cannot explain while using arduino mega as a I2C slave for a raspberry pi master. I am showing here an idealised program that shows the issue. I experience pretty much the ...
2
votes
1answer
643 views

Ardunio Mega/ATmega2560: Using Port F or K for both analog inputs and digital outputs

On an ATmega2560, can ports have some pins used for analog inputs but others as digtial i/o? Specifically, I only need to use 3-5 analog inputs but have many digital inputs. I would like to use the ...
2
votes
3answers
147 views

Conditional randomization gets stuck

First-time poster here... I have the following code to randomize note values and store them in an array loop1[i], where i is a specific step in the loop: nextNote = random(-2, 3); note = note + ...
2
votes
2answers
382 views

Trying to determine the phase difference between two square signals

I have been looking for the phase difference between two square signals and this is the code: #include <avr/io.h> #include <avr/interrupt.h> void setup() { //Serial.begin(9600); ...
2
votes
2answers
1k views

Error while boot loading Atmega 2560 using Arduino Mega 2560

I have developed custom board using Atmega 2560. I am doing boot loading process using the process of migrate from an Arduino board to a standalone microcontroller. I have followed this steps... 1) ...
2
votes
2answers
1k views

Programming ATmega2560 processor with FTDI instead of ATmega32

Has anyone tried to program an ATmega2560 with an FTDI chip as is done in the Arduino Nano (this is for a custom design). Will it work?
2
votes
1answer
33 views

Testing 433MHz Transmitter

Folks, There is a document named "Complete Guide for RF 433MHz Transmitter.pdf" available in the GitHub. There is a a connection diagram showing the Data pin of the Transmitter connected to ...
2
votes
1answer
54 views

Servo motor troubles

The image is as clear as I can make it. Here are the basics of my problem. My program is meant to make 6 red LED lights in sequence fade in and out, toggle 5 white LED's on and off with a button, and ...
2
votes
1answer
463 views

Arduino Mega and gyroscope erroneous values

I have Arduino mega2560 and MPU6050. I connected to Vcc pin of the gyro to +5V on the mega, the SDA to SDA pin, SDL to SDL pin, AD0 and GND to 2 GND pins. I used this code: #include<Wire.h> ...
2
votes
2answers
3k views

Arduino crashing during serial print for no obvious reason

I've written some Arduino Code which kept crashing and i couldn't find out why. Then i reduced the code as much as i could in order to see the problem. The reduced code currently doesn't do anything ...
2
votes
1answer
62 views

Why is their need of response time needed in esp8266 AT commands?

I am writing an AT commands firmware for esp8266 via connecting it to atmega2560. Now the question is how will I come to know the response time for AT commands for writing its firmware to read the ...
2
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0answers
105 views

Erasing all flash on boards with over 64kb of program memory

I'm using a Mega2560 board. My project needs to store some large constant data. To preserve the first 64kb flash chunk, I write these data on addresses beyond this limit. But there is either an ...
1
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2answers
69 views

Am not able to call C++ function pointers from inline assembly

Due to some curiosity, I was trying to use some assembly with my Arduino MEGA 2560. I am not able to invoke a function from a c++ function pointer array. When I uncomment the call function, func_a ...
1
vote
2answers
239 views

mega2560- Interrupts reading digital input

Hi I am very new to Arduino, with very little programming experience. I am using mega 2560 and trying to understand how interrupt works. I have a code written, it is very similar as the example ...
1
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2answers
5k views

Arduino with 12 bit DAC (MCP4725) Not Working

I have an Arduino Mega AT2560 and need to have real DAC. I purchased the Sparkfun 12 bit DAC, however I don't think it is working properly. I am using the Arduino wire library to communicate with the ...
1
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1answer
30 views

Problems in calculating and printing long unsigned integers

I have this code which provides an erroneous unsigned long number. CODE: char buff[100]; int unsigned long bytes; bytes = 48 * 70 * 144; sprintf(buff,"%lu bytes\n", bytes); BTPort.print(...
1
vote
2answers
332 views

Using HC-08 bluetooth module with arduino

I have an arduino mega 2560 and a recently purchased HC-08 module and the connection is as the following: Arduino | HC-08 VCC - VCC GND - GND 14TX3 - TXD 15TX3 - RXD When I power up the arduino it ...
1
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1answer
79 views

Strange Arduino Serial Behavior

I have a quirky question today. I have an Arduino MEGA 2560 with a very simple setup. It's connected to my pc over usb, and has one device connected on its onboard TX/RX2 port group. Whenever I open ...
1
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2answers
131 views

what will be the sampling frequecy of my arduino Mega 2560 code. How would I calculate it?

void setup() { // initialize the serial communication: Serial.begin(9600); pinMode(10, INPUT); // Setup for leads off detection LO + pinMode(11, INPUT); // Setup for leads off ...
1
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1answer
223 views

Set PWM by period? And have it variable?

In this other stack QA I'm asking about generating a pulse signal with a period ranging from 63 ms to 6.5 ms. There is a popular PWM library however it doesn't compile and also since 63 ...
1
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1answer
39 views

Serial Port fails with speeds greater than 19200

In Arduino Mega 2560 R3, properly selecting the Serial Monitor bauds, this code works with #define R 38400, but for some reason, not with #define R 19200 (?), #define R 38400 int rate=R; ...
1
vote
1answer
138 views

Switch statement cases not executing

Overview: I am trying to use a switch statement to run different tests. A main menu is displayed on the serial monitor, and then the user is given the option to enter their menu choice in the serial ...
1
vote
1answer
271 views

Using the Arduino compiler, is it possible to use Atmega2560 interrupt pins that are unused by Mega?

Looking into the schematics for the Arduino Mega I noticed that pins PE6 and PE7 are interrupt-enabled (INT6 and INT7 respectively); however, they remain unconnected to any Arduino I/O pin. I'm ...
1
vote
1answer
385 views

PROGMEM Corrupted Array

I am trying to store a large number of values into a couple of arrays using PROGMEM, but I am finding that a few of the values are read back corrupted. I am storing just 1s and 0s, but when I read ...
1
vote
1answer
254 views

Confusion over Transistors for a switching circuit with an Arduino Mega 2560

Apologies if this is a stupid question asked by a noob, but I've looked around to try and find the answer and just can't work it out. Basically, I'm making a project on thingiverse (Glitch's MK2 ...
1
vote
1answer
171 views

Controllino Debugging

Its a well known fact, that you can debug your arduino board with the help of an Atmel Ice. However, you might know the Controllino which is an arduino compatible device. It has an ATmega2560 on it. ...
1
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3answers
1k views

Understanding writing to input pins and pull up resistors

I am new to Arduino, and am trying to understand the following code. The question is: Is my understanding correct, or if not, what is happening here? I have to reverse engineer an existing ...
1
vote
1answer
32 views

where is the digitalPinToInterrupt macro defined

I am new to arduino, and it's confusing to me how you can just write code in the IDE and use functions or macros such as #define ISR() in the avr-libc library without having to include the header file ...
1
vote
1answer
112 views

Programming custom Arduino Mega with Arduino Uno

I'm making a custom board with AtMega2560-16AU as MCU and CH340G as bootloader (schematic can be seen in the picture). I have printed the custom PCB and soldered everything in place now I want to ...
1
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2answers
282 views

How to count the number of rising edges on DS3231 rtc?

I am using a DS3231 rtc and I would like to get millisecond accuracy from it so I decided to use the 32kHz generated clock from it. I wrote a code that would count the rising edges or falling edges ...
1
vote
2answers
96 views

Matrix keyboard and 7segment display countdown combination

I'm working on an escape room for my university with an Arduino Mega. The last part consists of a 7segment display representing a time countdown, and the participants have to introduce the correct ...
1
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1answer
3k views

SOLVED: Strange phenomenon with avrdude: stk500v2_ReceiveMessage(): timeout only with ATmega250 on windows 7x64

I know this problem has been reported multiple times but in my case I think there is a different light on it. My desktop is a w7x64 box and I also have a notebook with w10. Both system have the ...
1
vote
1answer
4k views

Rotary encoder I2C LCD menu

I am trying to make a menu for a monitoring/control system. I am not sure how to make this without interrupting my current code which needs to be monitoring my system at all times to shut off if it ...
1
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2answers
554 views

7 segment displays arduino mega 2560

I'm trying to use an Arduino Mega 2560 to use 7-segment displays, 6 displays... I use 3 CD4543B to pilot the 6 displays. It works very well for 4 displays as you can see in this video. But when I ...
1
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0answers
17 views

sim808 init error when trying to use DFRobot to get gps

I'm using "mega 2650 pro" Arduino with SIM808 BK-808 V-3.1 and I connect the vcc for the sim808 to 5volt pin in the arduino, and the arduino connected with laptop usb. and I add a sim to the ...
1
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0answers
42 views

ISR for timer on Arduino MEGA gets called only once

I am trying to write an Arduino code to blink LED using timer 4 on Arduino MEGA (atmega2560). I resetted the timer registers, and entered all the necessary values to bring to 16MHz to 1Hz (rescalar = ...
1
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0answers
55 views

it just gets too hot . any way of cooling it?

there i just got started with the arduino mega2560 . i tried 8x8 matrix tube and after ~30secs i found the atmega2560 a bit hot that i can melt a small amount wax on it ! is there any sort of heatsink ...
1
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0answers
75 views

Arduino mega PinChangeInterrupt with 16 bit timer

With reference to this question ::I have written a program by using 16-bit timer, The program is as follows . volatile uint32_t ovfCount = 0; struct Pulse { uint32_t last_toggle; uint32_t width; ...
1
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0answers
37 views

Fail to burn bootloader into standalone atmega2560

I am making a project where I use standalone atmega2560. I used arduino mega schematic to put all necessary components so atmega2560 would be working. I tried to burn bootloader into it using arduino ...
1
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0answers
55 views

Arduino mega reads ps/2 keyboard in C without arduino library [closed]

I want to read the input of an ps/2 keyboard. I connect the keyboard by a connector to arduino mega 2560. Clk to pin 2 and data to 30. Now my question how can i program in C that when I click any key ...