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Avrdude verification error after months of successful use

I have a 2560 that I've been working with for a while (over a year for sure), programming it with an avrisp mk2. No issue this whole time, then suddenly, a couple of days ago it starts failing with ...
kolosy's user avatar
  • 141
0 votes
2 answers
474 views

Assigning an element of a multidimensional array to a second array

I have two arrays. The first array is a multidimensional array holding color values. The 2nd array stores an active color from the 1st array. How can I assign an element from the multidimensional ...
VerySeriousSoftwareEndeavours's user avatar
0 votes
1 answer
472 views

Arduino Uno with ESP8266-01 with AT [closed]

Here is the schematic I followed: Here also the link: https://www.circuito.io/app?components=10167,11021,12083,13678,13959 #include "DHT.h" #include "NewPing.h" #include <SoftwareSerial.h> #...
Xiaomy's user avatar
  • 5
0 votes
1 answer
10k views

Store TinyGPS++ latitude value into a variable of type string or float

I want to get the GPS ordinates in degrees with 6 decimal accuracy. I can obtain this by creating a gps object with TinyGPS library. but In the TinyGPS example codes, its written Serial.println(gps....
Anum Sheraz's user avatar
0 votes
2 answers
5k views

I'm looking for a way to serially communicate with a multi mesh Arduino slave network

I have one PC running Visual Studio and a program that will be sending commands to Arduinos via serial COM Ports. So, in 11 Nano MCUs, I will have motor drivers L293D/L298N ICs, while in other Nanos I ...
Frank's user avatar
  • 51
0 votes
1 answer
300 views

How to interpret analog values sent to Arduino from line scanner?

So I have a line scan camera attached to my Arduino Mega and I'm trying to send it a digital clock impulse and get an analog output back. The line scan camera is supposed to return 128 pixels. So far ...
Fortuna Iwasaki's user avatar
-1 votes
1 answer
3k views

Avrdude verification error

I use an Arduino UNO with IDE 1.8.5 and for the last few days it doesn't let me upload any code. When I try, it pops up with the following error: avrdude: verification error, first mismatch at byte ...
Katerina Tsir's user avatar
48 votes
21 answers
141k views

Serial data plotting programs

I need to plot serial data from Arduino. I require support for: Various data formats (e.g. signed, unsigned, 8 bits, 16 bits); Plots several data on the same axes; Exports / Imports file data. As ...
akellyirl's user avatar
  • 2,146
45 votes
5 answers
157k views

What is the difference between Serial.write and Serial.print? And when are they used?

What is the difference between Serial.write and Serial.print? And when are they used? Both have been used to print on serial monitor, what are their actual differences?
shadab's user avatar
  • 569
42 votes
5 answers
47k views

Difference between Arduino.cc and Arduino.org

Recently I have noticed that there are two arduino sites, arduino.cc and arduino.org. They both have the Arduino logo and both sell what seems to be official Arduino boards. Also, arduino.org came ...
NULL's user avatar
  • 810
25 votes
1 answer
43k views

ATtiny85: Power consumption vs clock speed

Short and simple: What is the power consumption for an ATtiny85 running at 1 MHz and 8 MHz using the internal clock? Not using any sleep modes. I have googled a lot and can't find any info on this. I ...
marlar's user avatar
  • 467
23 votes
4 answers
24k views

Communication Protocol Best Practices and Patterns

Every time I design a serial protocol to be used between two arduinos, I feel a bit like I'm reinventing a wheel. I wonder if there are any best practices or patterns people follow. This question is ...
Jeremy Gillick's user avatar
22 votes
2 answers
10k views

Why can't I upload a sketch while other components/devices are connected to my Uno?

I wanted to make a fairly simple circuit which would flash a series of LEDs in sequence, using my Arduino Uno (more specifically, a SainSmart clone). I wrote my sketch and it compiled fine. After that,...
Peter Bloomfield's user avatar
22 votes
1 answer
28k views

How to access multiple SPI interfaces on Arduino

I have worked on SPI devices connected with an Arduino one at a time. How do I work with two different SPI devices at the same time?
Abhishek Kulshrestha's user avatar
21 votes
7 answers
26k views

Loading local libraries

I'm new to Arduino/C development (coming from a JavaScript/Ruby environment), but I was wondering if it was possible to include a library from a custom folder within a sketch? So this is my situation;...
Stefan's user avatar
  • 311
21 votes
8 answers
13k views

In Linux, how to identify multiple Arduinos connected over USB?

If I have multiple Arduinos connected over USB to a Linux computer, and they show up as /tty/ACM0 /tty/ACM1 /tty/ACM2 How can I identify which Arduino is which without connecting to them via ...
vlad b.'s user avatar
  • 719
19 votes
5 answers
78k views

deprecated conversion from string constant to 'char*'

What does this error means? I can't solve it in any way. warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
Facorazza's user avatar
  • 431
16 votes
3 answers
16k views

Arduino powering from 9V battery

Yesterday afternoon I have left my Arduino running on a fresh Alkaline 9V battery (+ connected to Vin, - connected to GND). Today morning (16 hours later) the LCD display was no longer visible, and ...
Suma's user avatar
  • 341
16 votes
6 answers
18k views

Arduino: How to get the board type in code

I want to write a sketch that can be compiled on different Arduino boards. I want to display on the PC which board is currently connected. This means that the user connects the PC via USB cable to ...
Elmue's user avatar
  • 481
15 votes
2 answers
10k views

Powering Arduino with Solar Panels

Clearly, an Arduino can be powered with solar panels. What is the most optimal configuration? Can you recharge and discharge at the same time? Is LiPO the best battery cache technology, or is there ...
0xF2's user avatar
  • 542
15 votes
2 answers
8k views

Why does an `.ino` file have to be in a folder of the same name?

I'm trying to organise a very complicated project and I want to put all the actual code in a folder named src (source), but I want to keep the main .ino file as main.ino (it will also be in src). Then ...
Dat Ha's user avatar
  • 2,913
13 votes
4 answers
7k views

Is setup and loop provided for convenience?

Arduino sketches usually feature a setup and loop function. Are these functions only provided for convenience or do they actually have special purposes? (e.g.: are some operations disallowed or ...
Sebazzz's user avatar
  • 231
13 votes
6 answers
30k views

Why do you need a second resistor when using a photoresistor/LDR?

A photoresistor is already a resistor and will limit the voltage in the circuit. Why can't this be connected to a pin and measured? Why is a second resistor needed to connect the photoresistor to ...
Jason's user avatar
  • 139
12 votes
2 answers
11k views

Will a .ino Arduino Sketch compile directly on GCC-AVR?

Okay, we all have seen those questions all over the web such as Arduino v.s. C++, or other similar questions. And a vast majority of the answers do not even touch compilation differences other than ...
RedDogAlpha's user avatar
12 votes
1 answer
9k views

Does the ESP8266 somehow remember wifi access data?

Today I did some tinkering with an ESP8266, trying out OTA and writing a webserver. To find an error, I reduced the sketch to just the following lines: #include <ESP8266WebServer.h> ...
Geier's user avatar
  • 233
11 votes
4 answers
147k views

avrdude ser_open() can't set com-state

When trying to upload the blink sketch to my (unofficial) Arduino Uno, I get the following error: avrdude ser_open() can't set com-state for "\\.\COM3" I have programmed this Arduino before using ...
rozzy's user avatar
  • 213
11 votes
4 answers
6k views

Choosing wireless tech for lowest possible lag

I am drafting a pub quiz project, where the Referee gives a signal and multiple players push their buttons. The first to push wins the right to give an answer. I want all buttons (referee's + X ...
Sergey Snegirev's user avatar
11 votes
4 answers
20k views

SAM3X8E (Arduino Due) Pin IO registers

How do the IO registers of Arduino Due work? On Arduino Uno just set DDRx, then PINx to read, PORTx to write, I'd like to do the same thing with an Arduino Due, but it has many more registers, such as ...
Alex's user avatar
  • 315
11 votes
2 answers
2k views

Understanding the compilation/linking/upload process (so I don't have to use the IDE)

I have started to play with and arduino UNO quite recently (without any prior experience with micro-controllers). I would like to use emacs instead of the IDE, and I'd also like to know what the IDE ...
Ash's user avatar
  • 225
10 votes
4 answers
6k views

How to move from arduino to physical prototype

I've been reading a bit about moving from Arduino to PCB and it seems a bit daunting. For now, all I really want to do is take something I've built, and make a few changes so that I can actually ...
mheavers's user avatar
  • 237
10 votes
3 answers
64k views

Convert to and from Unix Timestamp

What is the best way to convert between date, hours, min, seconds to Unix timestamp in milliseconds in Arduino? I need to have this conversion, since I'm using RTC (date, hours, min, secs etc) and ...
Dzung Nguyen's user avatar
10 votes
4 answers
60k views

Arduino compatible's serial port not showing Mac OSX

I bought an Arduino-compatible Freaduino board atmega8 (I selected the board type as Arduino ng or older atmega8). I installed the Arduino IDE on Mac OS X and the FTDI drivers. But my serial port ...
Rajath's user avatar
  • 225
10 votes
4 answers
32k views

2.4" TFT LCD Shield isn't working on Arduino Mega

Even on ebay's website it is mentioned that I can't use 2.4" TFT LCD Shield display on attach to Arduino Mega. The problem is that I bought this shield by mistake. I want to put this shield onto ...
Bay's user avatar
  • 305
10 votes
1 answer
3k views

How to design and debug a custom I2C master-slave system?

How to proceed, when in need of a custom I2C master-slave system? What are the design criteria to apply? What are the debugging tools one can use to troubleshoot problems?
Igor Stoppa's user avatar
  • 2,125
10 votes
3 answers
10k views

Upload code on Arduino Leonardo using command line

I'm trying to upload a compiled .hex file on an Arduino Leonardo, using the terminal. Uploading a sample code using the Arduino IDE works well, and from the Arduino IDE I got the upload command ...
Alex's user avatar
  • 315
9 votes
9 answers
7k views

Best way to determine if a 5 gallon water jug is getting empty

I have an espresso machine that gets its water from one of those 5 gallon blue water bottles (I would plumb it, but our water here is WAAAAY too hard). If I ever accidentally let the bottle run out ...
synic's user avatar
  • 203
9 votes
3 answers
14k views

ESP8266 Analog read interferes with wifi?

Short version: I have a program that connects my ESP8266 to WIFI so I can control a relay connected to it over the internet or a button. I also have a sensor for my door. This software works ...
JanG's user avatar
  • 193
9 votes
1 answer
2k views

How can the Arduino Uno support up to 12 servos if it only has 6 digital PWM pins?

According to this: The Servo library supports up to 12 motors on most Arduino boards and 48 on the Arduino Mega. On boards other than the Mega, use of the library disables analogWrite() (PWM) ...
user1265's user avatar
9 votes
3 answers
3k views

How to measure total energy usage of an arduino board

I have a project that I'm currently working on. We have built a green wall, wich consists of plants on a wall Now, we have a pump situated at the bottom that waters all the plants. There is an ...
DLJ's user avatar
  • 1,149
9 votes
2 answers
35k views

How to send numbers to Arduino UNO via Python 3 and the module serial

I am new to Arduino (and computer programming in general), so I apologize if this question looks silly. Once I set up a basic arduino-LED connection, I have problems sending INTEGERS to arduino ...
mickkk's user avatar
  • 271
9 votes
2 answers
4k views

How to update a variable in an ISR using Timers

I'm trying to check the frequency of Timer3 using a counter. The value of the counter, declared as volatile, is incremented in the ISR and every second the sum is shown in the main loop and the value ...
UserK's user avatar
  • 559
8 votes
2 answers
6k views

I fried the AMS1117 voltage regulator on my Arduino Clone, is this the cause?

I had the 12V DC power jack plugged-in all the time, and "to make things more exciting" I also plugged-in the "data" USB whenever I had a new sketch to upload. Is this combination a big no-no, or is ...
Jaroslav Záruba's user avatar
8 votes
2 answers
7k views

Male header pins on Arduino Uno

On my board, there are 12 (2 groups of 6, each group consistent of 3 rows of 2 pins) weird male header pins. What are these, and how would you use them?
Duncan's user avatar
  • 183
8 votes
3 answers
8k views

How to stop Arduino from drawing power through USB

I'm working on an embedded project, where I use arduinos as a "sensor shield" for RaspberryPi (I have model B). The problem is, that the RaspberryPi's USB port is not powerfull enough to drive WiFi ...
jnovacho's user avatar
  • 235
8 votes
1 answer
1k views

Arduino and ESP8266 Web server

First things first, if there was an ESP8266 StackExchange, I would post this there. I am setting up a web server that will programmaticly be controlled from an external Python script, and I am ...
Butters's user avatar
  • 393
8 votes
5 answers
41k views

Arduino Pro Micro, get data out of Tx pin?

I have a Sparkfun Arduino Pro Micro with an ATmega32u4 on it and a Roving Networks RN32 Bluetooth Module Theoretically, I should be able to solder the Rx of the Bluetooth to the Tx on the arduino and ...
user3320919's user avatar
8 votes
7 answers
134k views

What is commonly done to stop a servo after reaching desired position?

When I started Arduino, I did not expect that everything must be contained in an infinite loop. I thought I could just write something like: motor start -> motor stop. But in actuality, what I get is ...
Fraïssé's user avatar
  • 895
7 votes
4 answers
16k views

Watchdog timer stuck in restart loop? (green led flashing)

I am trying to set up a way to reboot arduino on command. The code below should do that but it seems like my arduino just get's stuck in some sort of a loop where I cant upload or get any serial ...
DominicM's user avatar
  • 597
7 votes
3 answers
1k views

Multiple SPI device

I want to connect Ethernet board (W5100 HR911105A) to Arduino Leonardo with SPI and I also want to connect SD reader. When I test these boards separately everything working. But when I connect them ...
eszik.k's user avatar
  • 121
7 votes
4 answers
5k views

Detailed analyse of memory usage

When compiling a sketch, after linking, the build outputs a kind of forecast on RAM usage, e.g.: Minimum Memory Usage: 1456 bytes (71% of a 2048 byte maximum) Is it possible to somehow get a ...
jarnbjo's user avatar
  • 328

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