All Questions
486 questions
-1
votes
1
answer
187
views
Have I fried the voltage input on my Arduino Nano?
I tried using my Arduino Nano in a circuit, switched on power to the circuit and heard a crack and smelt a bit of burning - something shorted.
I have plugged my Arduino into my PC with a USB, the ...
1
vote
1
answer
6k
views
Wemos: relay shield doesn't work on top of the stack
I connected a SHT30 shield to a Wemos D1 mini (one on top of the other) to measure temperatures.
Wemos D1 mini (2.3.0):
SHT30 shield:
It works great but when I added a relay on the top of the ...
- 448
0
votes
1
answer
479
views
Genuino UNO 5V pin is reading 0.3V
So I was trying to set up the LCD screen that came with my Genuino starter kit when I noticed that the board screen did not power on at all, unlike a few days ago when it worked.
In order to verify ...
- 103
1
vote
2
answers
2k
views
How do I use digital pin on sensor to analog on arduino uno
I am working on a autonomous fire extinguisher.i have run out of pins.I have the following question in my mind while working on my project
Is it necessary that the DO pin in a flame sensor must be in ...
- 111
7
votes
2
answers
20k
views
Use LoLin V3 pins starting with 'S' in Arduino
I have this LoLin NodeMcu V3 board:
What are the pins S3, S2, S1, SC, S0, SK?
Can I use them as GPIO in Arduino?
Thank you for your help!
- 173
0
votes
2
answers
395
views
simultaneously read 16 hall sensor and maximum current allowed by Arduino
My question is about maximum current allowed by Arduino.
I know it's 200mA in Arduino and 40mA in every pin (lower in arduino mini). Just wondering if simultaneously read 16 hall sensor (than can be ...
0
votes
1
answer
90
views
Designing around Output pin limitations
I'm new to Arduino and am working on a project with my son. We are using the LillyPad USB board (schematic) to drive a bunch of LEDs (LED Datasheet). Our project is based loosely off of the 'Turn ...
- 103
0
votes
2
answers
135
views
Can I support all these sensors?
I'm new to arduino's and am currently working on a project which requires a lot of different sensors. I was just wondering if its possible to use all the following sensors on a single Arduino Uno:
2 ...
- 1
5
votes
3
answers
993
views
Fool Proofing My Arduino IC Checker [closed]
I am creating an IC checker for some high school juniors since a faulty IC can be a nuisance of a bug to find when bread-boarding. These ICs are all simple TTL gating from the 74LS series; the set I ...
2
votes
1
answer
3k
views
Relay active low and ESP8266 GPIO pins
I am using a ESP8266, specifically the ESP-12-E :
I have a Relay, SRD-05VDC-SL-C connected to GPIO pin 4.
It is wired in Normally Open(with my device to be powered wired into the top and middle pins ...
RenegadeAndy
4
votes
1
answer
15k
views
Arduino Uno R3 to Wemos D1 R2 project migration - Pinout problems
So i've chosen to purchase a Wemos D1 R2 board in order that my old Arduino Uno R3 projects can get some new IoT features. However, even if my code is working in Uno perfectly, i want to test it using ...
1
vote
3
answers
401
views
How do I create a constant loop with an event that only occurs once?
I am currently working in void loop() and have setup a distance meter that constantly checks the distance.
Once the distance threshold is met, a function is called. Now I only need this function to ...
- 11
1
vote
2
answers
3k
views
What's the difference between DDRB and pinMode?
It's my understanding that the following lines are equivalent. They seem to be interchangeable in my sketch:
DDRB = 1<<DDB0;
and
pinMode(0, OUTPUT);
Is the first form (DDRB...) setting a micro-...
- 163
0
votes
2
answers
428
views
Accessing digital pins from the Atmega 16u2 on the Uno
I'm running a custom firmware on the ATmega16U2 (Switch-Fightstick).
Is it possible to access the digital pins of the UNO from the ATmega16U2?
- 103
2
votes
3
answers
10k
views
Is my HC-SR04 sensor broken?
I am extremely new to Arduino and electrical engineering, and the project I am attempting involves a ultrasonic sensor. I am using the HC-SR04 with the Elegoo Mega2560 Arduino board. A few days ago ...
- 23
0
votes
2
answers
6k
views
Fill an Array with Values
I have a function in which I change the pinMode on many of my Arduino's pins based on a passed in mode. I first construct an array of bytes specifying each pin to be an input or an output and then I ...
2
votes
1
answer
501
views
Consequences of dynamically changing input/output configurations of digital pin?
I am creating an IC checker for a large chunk of the 74ls series (basic TTL logic chips), which means that I have 14 pins running to the IC to verify its functionality. One pin is power (+5V) and ...
0
votes
1
answer
5k
views
Connecting multiple component's VCC wires to one Arduino UNO R3 5V Pin
Apologies for the title gore and whether this seems to be a fairly basic question, I'm an Arduino noob.
I'm working on a wearable sensor system project at my university using an Arduino UNO R3 to ...
- 3
-1
votes
2
answers
260
views
How to identify RGBW LED pins? [closed]
I have a RGBW LED but I don't know how to identify the negative and the colors pins.
I tried different combinations with an Arduino Uno but it never produce light.
I never used it so I am not sure ...
- 448
0
votes
1
answer
6k
views
Which input pins can I use on the ESP8266 NodeMCU
On the ESP8266 NodeMCU I have GPIO2 , GPIO3 , GPIO1 , GPIO9 free but when I assign them to a button they do not work. I assume it is because those pins have other function behind them. When I look at ...
- 101
-1
votes
2
answers
360
views
Can I change Vcc to some other pin?
I was working on an Arduino Uno and while carrying it to my teacher the wire's pin got stuck into the Vcc of 5 V. Can I set Vcc to other inputs? If so, then how?
- 1
-1
votes
1
answer
1k
views
What do the pins on this KS0107+KS0108 display do? [closed]
I got this display on ebay and I have no instructions on how to use it. I can guess what most of them do but I'd rather be sure I know what they all are instead of messing around trying to guess. The ...
- 113
1
vote
2
answers
2k
views
Arduino & RPi communication via GPIO [closed]
so I'm working on communication between arduino and RPi via GPIO pin.
It's basically connecting them by using a cable jumper. So I have a 2 channel relay shield attached to my arduino, and I've been ...
- 13
4
votes
3
answers
7k
views
can arduino on output mode sink current?
I have a arduino set below:
pinMode(1,OUTPUT);
digitalWrite(1,LOW);
Now, I am expecting 1.2mA current flow through the pin that is set as output. Is that accepted? If so, what it the max current a ...
- 103
1
vote
1
answer
4k
views
How to determine which pins_arduino.h file is used?
For some applications I need access to the registers that control the output/input and high/low state of pins. For example pin 10 on a adalogger is PORTB with a mask of _BV(6). This information can ...
- 205
-1
votes
1
answer
162
views
Arduino industrial 101 digital pins
I don't see anything that has been clear about which digital pins map to which physical ones. If someone could point me in the right direction it would be a big help.
For exampleThrough trial and ...
- 99
1
vote
1
answer
2k
views
How to keep a pin LOW for a small amount of time after pushing a button and while device is booting?
Context
I keep the board in deepsleep mode and want to wake it with different buttons. I need to know which button has been pushed on boot. The board is immediately put back in deepsleep mode ...
- 159
1
vote
2
answers
3k
views
Can any Arduino Due pin be used for PWM?
Arduino Due has 54 pins. It says that it has 12 PWM pins. I know it uses a more powerful chip than other Arduinos.
Can the number of PWM be increased?
Can any of its pin be used for PWM?
- 362
0
votes
1
answer
1k
views
Arduino analog pins not working
I am having a problem with pins of Arduino Uno. I have connected a LED to one of the analog pins (A0), and I want to light up the LED with different intensinty.
int ledPin = A0;
void setup() {
// ...
- 1
1
vote
3
answers
5k
views
digitalRead not reading input pin of ESP8266-01
I am trying to use a on-off switch with the ESP8266 to change whether GPI02 is HIGH or LOW. I am using GPIO3 as input. My circuit looks like this:
The red area to the right is a relay, I wasn't sure ...
- 173
1
vote
2
answers
397
views
Arduino mega board 5v pin does not gives 5v when 7.5v is applied through external source
I gave 7.5v to the arduino mega board through battery. 5v pin in the board gives me the same voltage as input. Earlier it was working fine now it is giving problem.Please let me know the solution as ...
2
votes
0
answers
226
views
Unable to send IR command
I am trying to switch the TV on using Arduino. Following is my set of code
#include <IRremote.h>
IRrecv receiver(2);
IRsend sender;
decode_results results;
long repeatitions;
long count;
...
- 289
1
vote
2
answers
647
views
How to connect a simple wall switch to arduino GPIO
I am trying to create a smart doorbell, but my problem is that doorbell makes ring any time when nobody touch the button.
I think that the problem is caused for the incorrect way to connect the ...
0
votes
2
answers
2k
views
Arduino Uno simple LED example with pointers
I am new to Arduino and I have recently started off by trying to turn on an LED connected to pin 13 on my Arduino Uno using pointers.
I opted to do this with pointers because this would give me a ...
0
votes
1
answer
372
views
PWM on Pin 4 - arduino Micro
I am using Arduino Micro. Is there any way to use PWM on pin 4 instead of Pin3 ?
I tried to change pins_Arduino.h but didnt worked.
//#define digitalPinHasPWM(p) ((p) == 3 || (p) == 5 || (p) ...
1
vote
1
answer
1k
views
Arduino Wire communication with MCP23008 GPIO pin expander to turn on an LED with a button press
I am using an Arduino Uno and an MCP23008 GPIO pin expander, I have a momentary button connected to GPIO 2 on the MCP23008 and an LED light connected to GPIO 1 on the MCP23008. What I want is for the ...
- 11
10
votes
4
answers
642
views
What is the proper way to make library pin mappings configurable?
I am working with some libraries that provide APIs for interacting with specific hardware chips (that makes these drivers?). However, different custom boards or shields will have the chip mapped to ...
- 203
0
votes
2
answers
53
views
Powering via an I/O Line
I have an SPI 128x64 OLED display. Is it safe to power this display's VCC from a digital I/O pin? I would like to do this so I can connect it flush to my arduino's header, and so I can control the ...
- 135
2
votes
1
answer
2k
views
Is it safe to short two pins together for conditioning a sketch?
I want to make a sketch which behaves differently, i.e.:
pinMode(pin1, OUTPUT);
digitalWrite(pin1, HIGH);
pinMode(pin2, OUTPUT);
digitalWrite(pin2, LOW);
pinMode(pin3, INPUT);
// And a user decides ...
- 123
0
votes
1
answer
102
views
Purpose of extra pin slots on Pololu DRV8835
I have a Pololu DRV8835 motor controller. I managed to properly solder and connect it and it actually works, however I've been wondering about the purpose of the extra pin slots - especially the ones ...
- 103
6
votes
5
answers
2k
views
Adding an LCD to Uno but not enough pins left
I am an absolute beginner and wanted to build a simple home automation system using DTMF module using this guide. My problem is out of 12 pins most of them are getting used in DTMF module(5) and the ...
- 61
0
votes
1
answer
140
views
Can anyone identify these headers?
I'm very new to the Arduino platform and micro-controller projects in general, which is why I'm still learning about all the parts needed for circuit creation. There is one particular part that I ...
- 3
0
votes
1
answer
8k
views
Using all ten capacitive touch inputs on the ESP32
I am using a Wemos Pro ESP32 development board and would like to be able to use all ten of the available capacitive touch inputs. I am able to get readings from nine of them but not T1. Here is the ...
- 161
2
votes
0
answers
106
views
Connecting Arduino Wifi shield to Arduino Uno based Mcore board
I am trying to connect this mBot board to an external network, that's why I bought the arduino wifi shield.
I am connecting the wifi shield to the 6pins (5V MOSI GND RST SCK MISO) of the mCore.
...
- 21
1
vote
2
answers
837
views
What not to do to an Arduino [closed]
I may have been working with my Arduino UNO board improperly,
because now it fails to upload sketches (says some programmer is not responding)
and when I press the cute little restart button, the ...
- 369
1
vote
2
answers
714
views
DigitalWrite Cannot Power HC-06 Bluetooth
To save power consumption, I tried to connect the HC-06 bluetooth module to a digital pin of my Arduino Nano. (HC-06 +5V <=> pin 11, HC-06 gnd <=> gnd) In that way, I can toggle the bluetooth ...
- 111
0
votes
2
answers
2k
views
How can the sensitivity of capacitive touch sensors be limited?
I have an Adafruit circuit playground classic, and the touch-pads are so very sensitive. From a centimeter away, they trigger. I would be happy to just have regular inputs, or to have the sensitivity ...
- 902
1
vote
4
answers
8k
views
Running a 7 pin OLED with 4 pins (I2C)
I have an OLED with this 7 pin pinout:
I want to use an existing code i found that makes use of U8Glib.
But in the example, use uses 4 pins to control the OLED via I2C.
This is the pinout he uses:
Is ...
- 1,435
5
votes
5
answers
2k
views
Is it possible to make normal pins act like ground pins?
So what exactly I am trying to do is control a motor and be able to turn it both ways without any extra parts.
So if the hmp was on (the plus pole) and the hmm (the minus pole) acted like ground the ...
- 53
1
vote
1
answer
10k
views
what is aref(analog reference)
what is the analog reference, I know that it can be used as a voltage reference, but not exactly what it is all about please someone help.
- 363