All Questions
486 questions
0
votes
1
answer
78
views
Arduino voltage connection pins
On the Arduino power connector jack, which is the positive terminal pin and the negative pin?
- 1
0
votes
1
answer
85
views
Using PortB as a sink, not working
Out of ideas here, i try using PB0-3 as sinks for a LED matrix and the pins just won't sink.
My test code:
void setup() {
//bitClear(SPCR, 6);
pinMode(PD5, OUTPUT);
pinMode(PB0, OUTPUT);
...
- 103
1
vote
1
answer
7k
views
Arduino Nano use SPI pins as I/O pins? and still be able to do ISP?
I wonder if can use the Arduino Nano SPI-pins(MOSI,MISO & SCK) as I/O pins in a sketch? and still be able to program over ISP?
Of course I will physical disconnect the Arduino from any other ...
- 127
3
votes
1
answer
4k
views
How to use attachInterrupt() in ATtiny85 with Arduino IDE?
It's possible use external interrupts/attachInterrupt() with the ATtiny85 when I program with Arduino IDE?
If is possible, how many inputs (for external interrupts) the ATtiny85 have and which are ...
- 31
1
vote
0
answers
460
views
Help Needed! How do I attach a color sensor to a 2WD robot and use it to control its movement?
I'm relatively new to the world of Arduino, so don't be frustrated if I ask questions that could be silly. This project has a deadline, so any input is appreciated.
THE PROJECT:
I am planning to ...
0
votes
1
answer
101
views
How to set a not plugged in pin to ground or Low
I have digital pin 7 when set to High it does and when set to low it does not.
The only way I can get consistent High or Low is to use a 2 position 3 pin switch with my pin 7 in the middle and ground ...
1
vote
0
answers
203
views
ESP8266 GPIO limitations with HC-SR04
I want to build a systems that measures if some parking spots are occupied or not. I chose to use an ESP8266 12-E NodeMCU Kit with multiple HC-SR04 ultrasonic sensors. In my project, it is essential ...
5
votes
3
answers
12k
views
What to do with Arduino floating pins?
I have some unused pins, should I connect them together and to the ground or leave them floating?
- 814
0
votes
2
answers
97
views
Read amount of I/Os in code
I want to write an Arduino code, that runs on several different Boards. The code can perform digitalRead/Write operations, but the pin number will be set from the user/outside. I want to include a ...
- 103
1
vote
1
answer
2k
views
What is the equivilent of PORTx for Teensy (4.0)?
I've seen people use code like PORTB |= 0x1 << 6 to set the sixth bit of PORTB in arduino. I understand that this is significantly faster than using digitalWrite. How can this be done using a ...
- 123
0
votes
1
answer
785
views
How to connect HC-06 BT module without pins?
So, from one popular Chinese store I ordered a HC-06 module that I received... and due to some mistake from a store, I received a HC-06 without connecting pins. So usually HC-06 looks like this (with ...
- 103
1
vote
1
answer
502
views
Multiple variant.cpp entries for same physical pin
Some variant.cpp files have more than one entry that points to the same physical pin. For example (from Arduino Zero's file):
// 14..19 - Analog pins
// --------------------
{ PORTA, 2, PIO_ANALOG, ...
- 145
1
vote
1
answer
152
views
Help, I want to turn relay constantly on until a difference is detected, but triggered only one instead
Help, I want to use arduino to control relay for electricity, i get data from a sensor and when a value is detected it should be constantly on until another detection triggered again, i can get the ...
- 11
-1
votes
3
answers
701
views
USING HX711 ( WITH LOADCELL) WITH PCF8574 IN NODEMCU
I have used hx711 and loadcell with nodemcu (esp8266) in its D1 and D2 pins ( here I have used Logic level shifter and a 5v supply to power hx711).It worked perfectly fine.
Due to the lack of enough ...
1
vote
0
answers
162
views
Non-Linear readings on Analog Pin A0 vs. other Pins A1
I discovered a curios behavior of my Nano v3. The analog Pin A0 seems to measure data in a non-linear way while the other pins seem to work normal.
Please have a look at the screenshot. This is the ...
0
votes
1
answer
783
views
Trying to read different gas levels with MQ2 Gas Sensor
I found a link on how to connect MQ-2 Gas Sensor to Arduino Uno.
http://electronicsprojectshub.com/how-to-connect-mq2-gas-sensor-to-arduino/
After I bought all the parts and tried it out, the sensor ...
0
votes
1
answer
2k
views
Use JYETech 2.4 Inch LCD Display Screen Module with Arduino?
I have this JYETech 2.4 Inch LCD Display Screen Module that I would like to use for a project I have in mind, however, I'm not sure how to wire it up with my Arudino Mega. Here is the datasheet for ...
- 41
-2
votes
1
answer
90
views
Can you use a 128 pin LCD on an atMega?
I found a couple old calculators and their LCD's have about 130 pins.
I was wondering if I can build an LCD driver to reduce the number of I/O pins, because I don't want to use like 14 I/O extenders; ...
-1
votes
1
answer
2k
views
4:1: error: expected initializer before 'void' [closed]
int button
void setup()
{
pinMode(13, OUTPUT);
pinMode(12, OUTPUT);
button 4;
pinMode(4=INPUT);
}
void loop()
{
if(digitalRead(4)== LOW);
{
digitalWrite (13, HIGH);
delay (250);
...
- 1
0
votes
1
answer
173
views
Understanding analog pins in pinMode
When passing the pin number in pinMode its possible to use A0 - A7, does it apply only to that methode?
How can pinMode expect a number (is it int?) type in case of digital pin another (is it then ...
- 157
2
votes
3
answers
432
views
Issue connecting heartbeat & temperature sensor on arduino uno but working individually
So the code is working individually for temperature sensor and for heartbeat sensor but when i combine it together it shows wrong values
for the temperature sensor
I'm using lm35 temperature sensor ...
0
votes
1
answer
1k
views
Do some arduino pins give signals when the controller starts?
For example, on the ESP32 board there are several contacts that can issue pulses when the controller starts, which is connected with the operation of the chip itself. It is not recommended to connect ...
- 263
-3
votes
1
answer
125
views
Can I power Raspberry Pi 3 via 3V3 and GND pin? [closed]
Can I power my Pi 3 using the 3v3 pin (pin 1) and GND pin (pin 6)? Also, if I want to protect the board from power surges can I just put a fuse between my power supply and the 3v3 pin?
Thanks in ...
- 107
0
votes
1
answer
464
views
Pin Mappings from Arduino Metro M4 Express Board to SAMD51
After looking through the internet, I coudln't find any document (not in the datasheet, no nice graphics on google image searches) that showed the mapping between the Arduino breakout board and the ...
- 113
1
vote
0
answers
170
views
Made a light controller for the holidays
I am a new the world of Arduino. I found on YouTube, how to build a light controller (https://www.youtube.com/watch?v=WvG9c84ApFA&t=39s). I follow every step but it doesn't work. Here are some ...
-1
votes
1
answer
374
views
Connecting 2-pin JST PH connector to Arduino Mega
I’m want to connect 50 LDR to my Mega, I wondering if I use a 2-female pin JST PH connector to connect the LDR, how can I link 2-pin male JST PH connector board to the Mega and does this board exist?
- 1
1
vote
0
answers
1k
views
HC-SRO4 always returns zero no matter what I do?
Wondering if it's the sensor or the code? can anyone help?
I've used the code here
/*
HC-SR04 Ultrasonic Sensor with LCD dispaly
HC-SR04 Ultrasonic Sensor
VCC to Arduino 5V
GND to Arduino GND
...
- 11
0
votes
2
answers
2k
views
Can a pin be Neutral, not high or low?
I'm trying to figure out a way to controll a DFplayer mini mp3 player with ADkeys.
Because I only have two or three files to play at a fixed volume I find it easier to just use the ADkeys. https://...
- 146
-1
votes
1
answer
5k
views
How come some Arduino Nano pins (D3, D4, A3, A4, A6, A7) cannot be set high?
I made a sketch to switch on all digital and analog pins, and found out several pins did not work as expected. Note: I manually put a jumper wire from each digital and analog pin (one at a time) to a ...
- 13k
0
votes
1
answer
342
views
Running out of GPIO & looking for suggestions
I'm working on a project using a NodeMCU and am quickly running out of GPIO pins. I'm trying to decide which way to go to complete it.
Right now, I have the MCU connected to a MAX31856 PT100 ...
- 1
1
vote
1
answer
546
views
Can I disable the TX pin by setting its mode to INPUT while still receiving data on the RX pin of a UART?
I'm using the ATmega328PB in a personal project with MiniCore. My board streams data in on the RX pin from another microcontroller, but my board also has a DIP switch connected to the TX pin, that's ...
- 131
1
vote
0
answers
240
views
Creating WebServer with 5000 port with AT command(ESP-01f)
I'm setting webserver with toggle led. I want to create global webserver. I`m mean hat use server with global ip. For it I must use port too. global ip/local ip:port.
I want to create on 5000 port. I'...
0
votes
1
answer
89
views
Arduino Due Digital Inputs without Response
On two of my Arduino Due, when connecting the pin 3.3V to any digital inputs (37,36,35,34), no serial message nor LED_BUILTIN is thrown as output, only the Test message.
Digital Pins are set as ...
- 337
1
vote
1
answer
2k
views
Output 3.3V when setting pin to high
I would like to pass 3.3V and Ground to an component. How can I achieve such a thing?
I for example would like to let a wire get 3.3V when I for example do digitalWrite(pin, HIGH). It is hard for me ...
- 131
1
vote
4
answers
790
views
How to set cables to connect CP2102 to Pro Mini?
How do I connect the cables in order to program the Arduino Pro Mini with the CP2102 usb interface?
The TX, RX and GND is easy, but I am not sure about the RST, DTR, DST, etc.
When I try cables like ...
- 252
2
votes
2
answers
332
views
measure +3V and -3V through resistor divider and switch on/off by digital pins
I've seen that resistor dividers can be used to read negative voltages, but I'ld like if there is a way to accomplish this with less components and having a way to turn this off.
I was thinking if ...
- 25
3
votes
1
answer
112
views
Which sources of randomness are available? [duplicate]
I need a souce of randomness to generate a seed to pass to randomSeed. Where can I get this randomness from?
Well, I hear I can read random noise from an unconnected pin.
But I need to connect 9 ...
- 131
1
vote
1
answer
3k
views
Can I use the PWM pins as regular digital input/output pins?
In regards to the arduino which has pwm pins, can I use these pins as normal input/output digital pins or not? Thanks in advance.
- 13
1
vote
0
answers
190
views
HC-05 Bluetooth module on breakout board with straight header pins
Has anyone found the HC-05 bluetooth module (on the breakout board) with straight header pins? I seem to only be able to find them with the 90 degree header pins. Removing those and soldering on ...
- 27
2
votes
3
answers
4k
views
Is there an alternative to soldering to connect boards?
I know that shields are usually soldered to headers so they can be attached to the board with the Arduino. I have a tremor, which makes soldering impossible. Are there ways of connecting PCBs without ...
- 123
-3
votes
1
answer
208
views
Spi based pin expander for Arduino
I don't have enough pins on my Esp32 board. I would like to use a pin expander. All the ones I could find online only use i2c. Are there ones available that use SPI?
I would like send pwm signals to ...
- 33
0
votes
1
answer
116
views
What type of power supply is the Arduino Due’s 5v pin and what is its current?
I’m looking to use a Futaba Servo with my arduino Due and was told it requires a “high current 5 volt supply” and I don’t know much about current so excuse my arrogance.
I know the arduino Due has a 5 ...
- 19
0
votes
2
answers
108
views
Ways to add pins in an arduino
I'm making a project for school where I'm using flex sensors and converting that into words on an LCD (similar to the signing glove if you're familiar with that).
I ran into a problem since the ...
Elijah Davis
0
votes
1
answer
455
views
Nodemcu ESP12-E (ESP8266), Can I reprogramming when the UART pins are defined as GPIO?
I wonder if there may be any problems using the pins that the UART are using as GPIOs, if now I want to be able to reprogram the circuit?
(Of course I will detach the ESP12-E from the mainboard before ...
- 127
0
votes
3
answers
512
views
For Arduino Uno it is possible to use the digital pins with PWM to read analog data, is this also possible with the Wemos D1 Mini?
I want to read out data from a load cell, for this I seem to need 2 analog input pins, the Wemos doesn't have this. In the Arduino I was also able to use the digital pint with PWM, there are also ...
1
vote
0
answers
121
views
How to stop and repeat a melody using a button?
How can we make our melody stop when we press the button the first time and repeat the melody when we press the button the second time?
// Noterna defineras
#define NOTE_B0 31
#define NOTE_C1 33
#...
0
votes
1
answer
259
views
What is the maximum number of sensors that can be operated on a single Aurdino unit
I currently have an Aurdiuno uno and a motor driver shield: (http://www.hobbytronics.co.uk/arduino-motor-shield).
Now, I would like to run the following mechatronic devices:
3 bi-direction motors,
1 ...
0
votes
2
answers
79
views
How can I discard power from a device I want to read from?
I want to read the data line from a device that normally interfaces with a controller. It has 3 pins, 3.3v power, gnd, and data. I don't need the power line since the Arduino will be USB powered and I ...
- 3
1
vote
0
answers
200
views
Cannot write pin LOW
All the other examples I've seen have had coding errors where they set a pin LOW in a loop with no delay so that it goes high again right away - but this problem is different, and probably something ...
- 111
0
votes
2
answers
3k
views
What data type are the analog pin labels (A0, A1, etc)?
Arduino Mega
I would like to have an array containing analog pin labels something like...
int analog_pins[] = {A0, A1, A2, A3};
int num_analog_pins = sizeof(analog_pins) / sizeof(analog_pins[0]);
Is ...
- 161