Questions tagged [pins]

"Pins" are like gateways between the Arduino code running on the chip and the components attached to Arduino. It can refer either to the physical connectors on the board, or it can refer to the pins defined in the code.

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Why isn't pin 6 on my Adafruit Feather RP2040 being sent high when I ask it to?

I have an Adafruit Feather RP2040 (pinouts) connected via pin 6 to a relay. The code (below) triggers the relay when a separate color sensor returns "enough" red values. The color sensor ...
Jeff Schaller's user avatar
0 votes
2 answers
111 views

Just one more pin!

I have an Arduino project to control a motor's speed at 3 levels, indicated by 3 LEDs, so level 1 is speed 1 and LED 1, and so on for levels 2/3. Also, I added a low-battery voltage indicator to ...
Tito's user avatar
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1 vote
1 answer
37 views

Weird Behaviour with BearSSL on GPIO ESP8266

I use GPIO 5 to trigger a relay, my code also connects with a secure MQTT connection for which I have to use the BearSSL certificate definitions. Without the BearSSL certificates, when the esp ...
Shreyansh Jain's user avatar
4 votes
2 answers
236 views

Trying to resolve invalid conversion from 'byte' {aka 'unsigned char'} to

I'm trying to use an existing Arduino library on the Raspberry Pi Pico. The library is here: https://github.com/j-bellavance/EdgeDebounce/tree/master It's based on some interesting insight at Jack ...
Jeff Haas's user avatar
1 vote
0 answers
57 views

Selecting the Right GPIOs

I've bought this 4 relay ESP8266 board to active lights and window shades. In an odd way - its relays are not pre-connected to a certain IO's but let you choose which IOs will operate relays (by ...
guyd's user avatar
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2 votes
2 answers
148 views

Barebones AVR - Connecting RESET pin to Vcc

I want to build my first barebones AVR circuit. I plan on NOT having a RESET button. For this reason, is it valid if I connect the ATMEGA's RESET pin to Vcc directly? What I mean by this, is that in ...
user1584421's user avatar
  • 1,385
3 votes
0 answers
44 views

Can I use regular pins (Example: D2, A3, etc...) as serial (RX, TX)?

Python/Arduino Beginner here... I have a DFplayer I am trying to hook to my Arduino and I want to hook it up through the regular pins instead of the RX and TX pins, but I've not been able to find ...
prestonferry's user avatar
2 votes
1 answer
83 views

Remap SPI functions to default pins Arduino Zero via software?

I am looking at the documentation for the Arduino Zero, and I am a little confused. It indicates that pins 13, 12, and 11 can be used for CIPO, COPI and SCK, but using SPI.begin() puts the signals on ...
eramirez2024's user avatar
3 votes
0 answers
109 views

Raspberry pi pico (Arduino core) not initialising SPI correctly for NRF24l01

I'm working on a project where i have a Raspberry pi Pico connected to a NRF24l01+ to send some data. However i'm not recieving any data on the reciever and i think that its because the SPI bus is not ...
Earthbound Ruben's user avatar
2 votes
1 answer
96 views

What type of pin header is this?

Most of the Arduino uno boards have black female pin header. when i bought a ardiuno uno the digital pins 0 to 7 are made of silver pins. What type of pin header is that? How to use these kind of pin ...
Alwin Varghese's user avatar
-3 votes
1 answer
67 views

Read status of digital pin 11, when it is set as OUTPUT

I have set pin 11 as output. pinMode(11, OUTPUT); However, I want to be able to read its state (if it is HIGH or LOW), however since it is set as OUTPUT, I am not able to use digitalRead(). I found ...
user1584421's user avatar
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0 votes
3 answers
335 views

How to Protect GPIO when using long wires?

I want to connect a normal toggle switch with one of the gpios pins of a tasmotized esp01 with a wire about 20 feet in length. When I tried this before, I lost the GPIO pin mostly due to the high ...
SHEMIN A SALAM's user avatar
-3 votes
1 answer
780 views

If Arduino digital pins can be used as power supply pins then why do we need VCC pins? [closed]

If Arduino digital pins can be used as power supply pins then why do we need VCC pins? VCC pins work the same as digital outputs , don't they? So why do we still need VCC pins to power components
Nathan Francisco-Ribeiro's user avatar
0 votes
1 answer
174 views

Duinotech ATTINY85 Pinout

I'm sure this is a super nooby question but, what is the pinout of the Digispark ATTINY85 Development Board The board looks like this: Now the reason why I'm asking this question, when I do ...
Coconut's user avatar
0 votes
1 answer
164 views

Why doesn't my mcp23s17 interrupts work anymore?

I'm using a teensy 4.0 with two mcp23s17 gpio expanders where #1 has 16 buttons wired to it, and #2 has 4 buttons and six rotary encoders. To run everything I'm using majenkos mcp23s17 library. ...
Erik's user avatar
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3 votes
1 answer
353 views

I'm using nRF2401 and in my transmitter and receiver the Rx is not blinking and Tx is blinking; why does Rx not blink?

I did a search on the meaning of RX and TX and it seems TX means sending data and RX means receiving data. So when my transmitter is turned off, my receiver looks like this and it works with a battery:...
dagh's user avatar
  • 31
2 votes
1 answer
330 views

What components can be connected to pins 0/1 (RX/TX) without preventing uploading of code?

For a robot project I am using an Arduino Uno, and am running out of pins. The simplest solution would be to use digital pins 0/1. I know this means that I won't be able to use Serial communication (...
Rustony's user avatar
  • 31
3 votes
1 answer
123 views

Why am I reading only zeroes from PORTB?

I am using a custom Arduino Nano compatible board with an Atmel 328P. I am externally changing the values applied to several pins on PORTB. I expect to be able to read the values of these pins (low ...
Joe's user avatar
  • 33
2 votes
1 answer
122 views

Safe to solder a slide switch to unused GPIO pins?

I have a Digispark Rev.3 Kickstarter with ATTiny85 (see pinout below) and a three pin slide switch (see example below). I want to use the slide switch to control a task running on the Digispark, with ...
emma.makes's user avatar
3 votes
2 answers
3k views

How to toggle a pin (LED) simply

I am not a programmer but rather a hardware guy. In the good old machine code days, you could 'read' the status of the port and flip it.. admittedly a much simpler processor. Is it not possible to do ...
Colin's user avatar
  • 41
0 votes
1 answer
343 views

How do I instruct the L293D to operate a motor at full speed when using 3.3V GPIO pins?

If the L293D enable and input pins expect [up to] 5V inputs; what is the best way to deliver full power to the output pins when using an ESP32 or any other microcontroller which uses 3.3V GPIO pins? I'...
HardlyNoticeable's user avatar
-1 votes
1 answer
2k views

How to use ESP-01 GPIOs for input?

I'm trying to use one of ESP-01 GPIOs as an input, however, I'm always reading 1 and nothing attached to these pins. Basically, I'm trying to detect high voltage from another sensor like a touch ...
motion channel's user avatar
0 votes
1 answer
51 views

Can pin mode damage Arduino with connected electronics?

I am not that experienced with electronics, so this might be a silly question. But I dont know. Assume that I have connected some electronic circuit (transistors, leds, anything else) to the Arduino ...
Lemonbonbon's user avatar
1 vote
0 answers
98 views

Can I use AREF to supply a circuit, when in internal mode? (Nano)

When analogReference(INTERNAL) is set (1.1V), can I use the AREF pin to supply a circuit? E.g. like this: AREF —— R1 —— button switch —— A4 —— R2 —— GND where A4 is configured as analog input (...
Grimaldi's user avatar
  • 111
11 votes
3 answers
8k views

Why are the pin numbers of the diagrams and of the code different?

If I search Google for "arduino nano pin numbers", all results show that the pin number of D2 is 5. But that did not work. I searched for some sample codes, and they were 3 for D3 and 5 for ...
Damn Vegetables's user avatar
0 votes
1 answer
457 views

Problem Using pins A4 and A5 for input and output I2C

Hardare used: Arduino nano ( old Bootloader ) Oled Monochrome Display ( 4 pins, 128 x 32 ) MPU 6050 Both display and MPU use A4 and A5 as I2C communication protocol, They interfere, as the MPU is used ...
Aliph Null's user avatar
4 votes
1 answer
408 views

Arduino UNO won't move servo

I have a simple MG996 servo motor and I am trying to make it move with my Arduino Uno. I tried different ways of wiring but nothing seems to work as fully expected. For the wiring I followed this ...
Yulian Prodanov's user avatar
2 votes
2 answers
4k views

Input vs input_pullup

I'm a beginner in Arduino and can't understand some things. How does input pin in Arduino work? I want to set one of the pins as input. When should I use input and when input_pullup? What are the ...
Maciaz99's user avatar
0 votes
1 answer
707 views

Safe to power LED strip via ESP32 GPIO

I want to rewire a battery powered LED strip (as shown in the picture below) to power via an ESP32's GPIO pin. I have a ESP32 NodeMCU Development Board, powered via USB. The LED strip has specified 3,...
emma.makes's user avatar
1 vote
0 answers
46 views

Can I support all these sensors? Will I have enough pins?

So i'm new to arduino and i'm working on a project that will require 3 modules/sensors. I wanted to know, can all of the following modules work with the arduino mega 2560 that comes with this touch ...
Shimon's user avatar
  • 11
4 votes
1 answer
52 views

Custom LED toggling function: one out of three LEDs misbehave

I connected three LEDs to an Arduino Uno and wrote a simple LED class. I toggle all the leds the main loop, but for some reason one led (connected to pin7) always misbehaves, skips one toggle or stays ...
Jurc192's user avatar
  • 73
1 vote
1 answer
605 views

Select pin to connect RF receiver

I use the RCSwitch library receive signals with a RF receiver. I really need to change the pin the receiver is connected to on my Arduino Uno. What should I change in my sketch? What pins can I ...
ainnnmanir's user avatar
1 vote
1 answer
293 views

Accessing Physical Pins in Arduino Due from Arduino IDE

It is possible to access the Physical Pin 93, Pin PC11 on ATSAM3X8E in Arduino Due from the Arduino IDE? I am programming a Barebone ATSAM3X8E, and it do not seems to be allocated by Arduino Due nor ...
Brethlosze's user avatar
4 votes
1 answer
116 views

Wirelessly (but fast) transfer STEP and DIR output from Arduino to stepper driver

Very short version: Looking for a way to wirelessly get STEP and DIR signals (only those two signals) from an Arduino to a DRV8825 stepper driver about a meter away: Arduino -> STEP and DIR IO pins ...
Jasper's user avatar
  • 141
1 vote
1 answer
674 views

How to connect an Output to a Pullup Input of another arduino

:tldr; Could problems occur if one connects a HIGH Output of one arduino to a PULLUP_INPUT of another while using differed power sources? Hi I'm building some devices for a LARP Dungeon (think Escape ...
Karl Sanathos's user avatar
3 votes
4 answers
1k views

Can internal and external pull up/pull down resisters be used together?

What happens if a sketch uses code like pinMode(18,INPUT_PULLDOWN) to configure internal pull-down (or pull-up) resistors, but is used in a circuit where external resistors are also present? Are there ...
JRI's user avatar
  • 200
0 votes
1 answer
84 views

Check pin capabilities at compile time

Are there board-independent functions to check pin capabilities at compile time? I.e. Can the pin be used as output, as in digitalWrite()? Does the pin support PWM, as in analogWrite()? Does the pin ...
Dmitry Grigoryev's user avatar
1 vote
0 answers
38 views

How to avoid two arduino components using the same digital PIN [duplicate]

I'm trying to build an Arduino project where it involves a TFT and an ethernet W5500 component. Here's the project I want to build to learn Arduino. However I wanted to change the board that already ...
JuniorPenguin's user avatar
1 vote
0 answers
52 views

Can I create an hemi-cycle raising signal with one pin and the other hemi-cycle signal with another pin?

I am new to Arduino, I would like to know if someone could help me to create this type of signal with the Arduino Uno. Many thanks!!
Edgar Hornus's user avatar
1 vote
0 answers
31 views

Touch sensor trouble

I need help I use Touch Sensor(T)v.0 and it always receives a signal not matter I touched it or not. Here is the code. #define TOUCH_PIN 7 int touchVal = 0; void setup() { Serial.begin(115200); ...
Shushan Abovyan's user avatar
2 votes
1 answer
2k views

Can't Turn Off Internal I2C Pull-Ups on ESP32

I've designed a custom ESP32 board around the WROVER-IE module. To keep power low, I'm using a GPIO-controlled high-side FET to turn off unused peripherals when in deep sleep mode. The issue: I've ...
Nick Johnson's user avatar
0 votes
1 answer
49 views

I have five pushbuttons that refer to a specific pin number. I need an efficient code to set the variable for the pin with state 1. What can I use?

There are 5 push buttons each which correspond to a certain pin let us use 1 to 5 for an example. I want to set a variable, ActiveButton which will be set equal to the the only pin in the one state. ...
AndroidV11's user avatar
1 vote
0 answers
48 views

Directly synthesising an OOK modulated LF signal using a CSV file

I'm looking to transmit some data (CSV files) from a measurement instrument underground to a receiver on the surface. I've learned that in order to penetrate the limestone, low frequencies have to be ...
K. Millar's user avatar
1 vote
0 answers
83 views

Trouble with laser sensor

I have trouble with my laser sensor it doesn't work properly. When I connect all pins its doesn't work, when I remove GND and connect just the signal pin and VCC it works but the laser light is dim(I ...
Shushan Abovyan's user avatar
0 votes
1 answer
135 views

Does setting a value always mean setting a Arduino pin?

One thing that always confused me was why we use int or other commands to set the variables to have pin numbers as if those commands were always restricted to pin numbers only. For example int ledPin =...
AndroidV11's user avatar
0 votes
2 answers
1k views

Portenta pinouts for ADC

I wanted to have your comments about one of my questions. I am currently working on the sketch for the Arduino Portenta H7. However, due to my poor electrical background, I would like to ask your ...
Basit Ali's user avatar
0 votes
1 answer
144 views

What is the pinout of the Arduino MKR motor carrier when using external power supply, not the Li-Po battery

I see there is a blue terminal connector an the tags below the PCB Vin, 5V, 3,3V and GND, but I am unsure where should I supply voltage to power up the board. Also, in the product page it says the ...
Dan's user avatar
  • 3
1 vote
2 answers
285 views

Switch on the piezo emitter for a short time

I need a short beep for every minute of change. I wrote a separate function. The signal duration should be 50 ms, the rest of the time the emitter connected to the A1 contact should be silent. A ...
Антон's user avatar
1 vote
3 answers
1k views

Short circuiting GND and power pins

I have created an arduino shield and i want to measure the voltage between the GND pin and 5V pins, to see if i see a voltage difference between the two points, in order to test if my pcb is fine. My ...
user1584421's user avatar
  • 1,385
0 votes
1 answer
426 views

Cant find Sdl and Sca pins in lcd display

My project is of non contact temperature sensor.I am using RG1602A lcd display and mlx90164 temperature sensor. But the problem is, there's no sdl , sca pins in my lcd display. Is there any way, to ...
Etf_Zan's user avatar

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