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1500 questions
10
votes
4 answers
Which shield to use for GPRS?
I'm planning to build a device that would read some sensor data and send it via GPRS, eg. once per day. (Not that original, yeah.) But my problem is choosing a GSM/GPRS shield.
The official shield has a nice interface for doing an HTTP POST/GET.…
tuomassalo
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10
votes
4 answers
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 Arduino Mega 2560. Is there a way to combine Mega and…
Bay
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9
votes
2 answers
Can the 2nd MCU on the UNO R3 be used for keyboard emulation?
Following on from What's the 2nd ICSP header for in Arduino Uno R3? I was wondering how this could be hacked to our advantage.
For example, could that firmware be rewritten to have the UNO recognised as a mouse/keyboard input? Could this be done…
Madivad
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9
votes
3 answers
Can I make the Arduino ignore serial print
I like having serial communication for debugging and testing purposes but after a while it takes away too much speed from the sketch.
Is it possible to have the Arduino ignore serial.print and serial.println throughout my code, without turning it…
Kevin Kroon
- 93
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9
votes
2 answers
Remove unused boards from Arduino IDE
In the current project I'm programming simultaneously an UNO board and a Leonardo one.
Switching back and forth between the two boards in the Tools menu takes too much time because of the other 18 boards that I do not own anyway.
Is there a way to…
Paolo Zanchi
- 951
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9
votes
2 answers
What is the maximum wire length for serial communication between two Arduinos?
I am building a project in which two Arduinos will be linked by three wires: TX an RX for serial communication and a common GND. What would be the maximum length of the wires here before communication gets affected?
I am using an Arduino Mega R3 on…
hobie
- 487
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9
votes
3 answers
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 arduino board that decides when to put the pump on.…
DLJ
- 1,149
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- 10
9
votes
2 answers
How frequently do you need to poll UI buttons before they are perceived as laggy?
Whilst it is possible, and sometimes desirable, to use pin change interrupts to read the state of buttons, it is simpler to poll the state of buttons in loop(). This is a commonly used technique.
If you loop() executes quickly enough, then button…
Cybergibbons
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9
votes
1 answer
Can you query the current serial port's speed?
Is there some code I can use to find out what the a chosen serial port's speed is running at ?
Hayden Thring
- 318
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- 10
9
votes
2 answers
Arduino interruption (on pin change)
I use the interrupt function to fill an array with values received from digitalRead().
void setup() {
Serial.begin(115200);
attachInterrupt(0, test_func, CHANGE);
}
void test_func() {
if (digitalRead(pin) == HIGH) {
…
user277820
- 91
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- 4
9
votes
2 answers
Reading a varying voltage into Arduino
Using an Arduino Nano and a current transformer (CT), I'm trying to sense the current flowing through a 120 V 60 Hz line.
Circuit
CT outputs 0-1 V according to its specifications. This output is biased AREF/2 = 2.5 V.
analogRead Values
The…
Nyxynyx
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9
votes
5 answers
Same structure taking different memory space on Uno and NodeMCU ESP8266, leading to data corruption when transferring via nRF24L01+
I'm trying to transfer data between a Arduino Uno board to a NodeMCU ESP8266 board, using nRF24L01+ transceivers module and RF24 library on both side. The data I'm transferring are stored in a struct defined this way:
// Struct declared in both…
Vincent
- 232
- 2
- 10
9
votes
1 answer
Confuse about PROGMEM and R"====()===="
I saw the following code from https://circuits4you.com/2018/03/10/esp8266-jquery-and-ajax-web-server/ but I could not understand it thoroughly...
I looked at the documentation of PROGMEM from this…
Mark Estrada
- 233
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9
votes
3 answers
Bootup on lower power not functioning
I have a custom Arduino ATMega328 board that generally runs at 5V @ 8MHz (using the Arduino Pro 3.3V 8MHz profile and bootloader). The main reason I'm using this setup is so that I can put the board to sleep when main power is disconnected and it…
Adam Haile
- 599
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- 14
9
votes
2 answers
What is difference between NodeMCU and esp8266?
Since I have no previous experience in electronics I'm getting quite confused while coming across these two terms ..I'd like to know whether they're the same or different.
User 1426833
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