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Questions tagged [arduino]

Be sure to use the Arduino Stack Exchange for questions that are more Arduino and less electronics.

0
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4answers
120 views

Ohm's Law and Death

So I bought an Arduino today, my high school grades were terrible but I decided to dive into electronic engineering anyway. I am a total noob so please forgive me. So Ohm's law states v = R * I, ...
1
vote
2answers
116 views

How is it possible to ever have frequency on a DC circuit?

Preface Please read this carefully. I put a lot of time into it and am genuinely attempting to understand. I've read numerous articles about DC and AC circuits and searched numerous places to get ...
0
votes
0answers
24 views

Controller Hang(Unresponsive behaviour) Issue

I am using avr atmel 1284p and sim808 for sending data to remote server via HTTP. I am using watchdog library "avr\wdt.h". ...
-2
votes
0answers
32 views

How can I measure RSSI of an antenna with an Arduino? [on hold]

How can I measure RSSI (Received signal strength) of an antenna with an Arduino? Is it sensible to use ESP8266 with Arduino for this?
0
votes
2answers
63 views

How to determine the physical location on a RS-485 daisy chain / bus topology?

I am trying to build a "daisy chain" using several Arduinos and MAX485 transceivers. All boards have a temperature sensor attached to it. A 9V battery supply all boards in the chain. I am trying to ...
-2
votes
1answer
65 views

DC signal output 0-5V with constant 10mA

I am designing a Digital Logic Board and need to add a DC signal output from 0 to 5V (with potentiometer) with a constant 10mA. I have checked designs with LM317 and LM334 for adjustable current upto ...
0
votes
1answer
16 views

Running Relay in parallel to switched neutral rocker switch

Complete beginner here, so apologize if this is obvious - but I'm trying to hook up a fog machine to a relay module for my Arduino. The Fog machine has a plug for the wall, then a second drop cord ...
1
vote
3answers
73 views

How to improve an elegant design for an LED dimmer, low-powered with LDO

I am building a sunrise alarm clock. The LED is supposed to get brighter over the course of 30 minutes, then remain fully lit for another 30 minutes, then switch off. I am using a digital pin on an ...
-1
votes
0answers
7 views

Use CC2451(JDY-08) module stand-alone

i've been using cc2541 module with arduino an just used pins rx tx vcc and gnd. i wanna know if it's possible to use cc2541 board stand-alone. so i can just load arduino sketch to it.
-1
votes
0answers
13 views

Setting wifi password and username from Mqtt dashboard

I am looking for sample code .Where i could take wifi SSID and password from Mqtt dashboard. I am using nodemcu with DHT11. I could able to communicate with DHT11 using client code. Its easy to do ...
2
votes
3answers
132 views

Controlling Solenoid Valves with ULN2003A, Inrush Current, Arduino

I want to control a total of five solenoid valves with my Arduino. The solenoid walves operate at 12 volts and have a power consumption of 5 watts per solenoid valve, which equals a current of roughly ...
0
votes
0answers
18 views

rfduino i2c no activity on bus

I've been working on RFD22102 RFduino with the USB shield. Using the board manager in Arduino IDE to retrieve RFduino package under the URL "http://www.rfduino.com/package_rfduino166_index.json" ...
0
votes
4answers
47 views

How to power an Atmega328P and Pi from 12V?

I have a bare-bones Arduino (basically an Atmega328P) and a Raspberry Pi 2. I have them communicating with each other over I2C and a 5v/3.3v logic level converter. Right now I power the Pi (micro-usb)...
0
votes
2answers
51 views

LM324 with arduino as a differentiator for phototransistor signal

I want to measure the rate of change of voltage with respect to time coming out of a phototransistor, and preferably amplify it at same time, as the change is not so significant. But lets just not ...
0
votes
1answer
45 views

How would I go about measuring an analog signal that has both positive and negative voltages on an arduino analog pin at a high sampling rate?

I have a signal that fluctuates between -70mV and 50mV. How would I get the arduino mega to read this on an analog pin at a high sampling rate? Ultimately I am trying to graph the data in real time so ...
0
votes
1answer
63 views

Several noob questions about Arduino and electronics [on hold]

I spontaneously bought an Arduino yesterday. I am amazed by the complexity and yet the simplicity of it, finding it absolutely fascinating. I have some questions thought: Does the number/string next ...
0
votes
0answers
15 views

Looking for a multi-channel RC relay module [on hold]

My current situation is this: I am building some type of a wireless system that automates industrial stack lights based on the state of an SQL database. As of right now I am using an Arduino with a VB....
0
votes
1answer
45 views

Protect signal from noise in Arduino

I am trying to send a signal from the Arduino to a relay to open a switch. My problem is that my Arduino will be near the AC power lines. I searched for how to prevent the noise to ruin the signal ...
0
votes
2answers
75 views

Why are my op-amp (LMC6484) output signals not independent of each other?

I am using a quad op-amp (LMC6484) in a non-inverting circuit. Using only one of the 4 op-amps I was able to amplify Vin = 80.3 mV to Vout =1470 mV. Rin=2.66k Rf=10k. V+= 9V… V- = -9V My problem is ...
0
votes
2answers
85 views

Recording of sensory nerve evoked potential generated through skin-receptors

If we touch / give pressure to a skin, there are many mechano-receptors like meissner/pacinian corpuscles that produce action potential in neurons. I am in a need to detect those action potentials ...
0
votes
1answer
66 views

How to drive a 1MHz Ultrasound-TD1000KA

I want to measure the Sediment of water. So I chose a 1MHz Ultrasonic Transducer sensor with the ability to work underwater and also can recognize the sediment under water. The output of the sensor ...
1
vote
0answers
35 views

Can the idle state of MOSI cause issues?

I have an issue when communicating with an ADC over SPI. If I imitate the SPI protocol via bitbanging then I have no issues with communication; however, if I use the SPI hardware (I've tried Arduino ...
0
votes
2answers
76 views

RS485 transceiver design

I'm working on a TTL to RS485 transceiver which is part of a bigger project (arduino based) and I came up with the following design: I have a few questions: 1) I have seen very different values for ...
0
votes
1answer
47 views

How to tell a battery's ideal charging voltage with a circuit?

simulate this circuit – Schematic created using CircuitLab I've been looking to build a universal charger for my laptop and phone, and I'm wondering; is there a viable way to adjust the input ...
-1
votes
0answers
30 views

audio quality and safety devices of a passive audio mixer

This is my first question here on stack exchange. I have searched a lot for this question but could not really find the answer precisely. At the moment i want to make a simple audio summer, using an ...
1
vote
0answers
67 views

(Arduino) When turning TIP120 on again, sometimes the slave flashes trigger without being told to. Why?

I have two mini slave flashes, that have no stand-by modes by themselves. So, even when charged and ready to flash, current keep flowing from the two AAA batteries each, and, if I forget to turn them ...
0
votes
4answers
83 views

Why some Arduino LEDs are not grounded

Looking at the schematics of the Pro Micro, the LED in PD5 (bottom-right) is connected to VCC instead of GND, same for PB0. Why? ...
1
vote
1answer
30 views

Change operational mode of CAN transceiver

I have two MCP2515 stand-alone CAN controllers with SPI interface, two TJA1042 CAN transceivers and two Arduino uno boards. As you may know TJA1042 have 2 operational modes: sleep mode normal mode. ...
4
votes
1answer
75 views

Problem with SPI Communication between Arduino/Atmega328P and Raspberry Pi

I have an Atmega328P chip (being used as an Arduino) that I would like to connect to a Raspberry Pi via SPI. I originally had an Atmega328P running on 3.3V using its own internal 8MHz crystal ...
4
votes
2answers
583 views

Multimeter true RMS [on hold]

I'm just getting started with electronics (arduinos and friends) and I would like to get a multimeter. As far as I can tell arduinos and any other logic chips and circuits I'm gonna be using are using ...
0
votes
1answer
96 views

Servo wire connection layout [on hold]

I'm trying to figure out with E-flite 7.6g Sub-Micro Digital Tail Servo JST my particular one has 1.0mm to male JR connector, so need to be connected with some switch, I have 2 other servos here, ...
0
votes
2answers
54 views

Simulate Arduino keypad with Arduino

I came up with idea to create a simple keypad lock using this ( Keypad Matrix 3x4 https://grobotronics.com/keypad-12-button.html?sl=en https://learning.grobotronics.com/el/2013/07/using-a-3x4-keypad/ ...
0
votes
0answers
27 views

calculating NDVI with the TSL2561 and what is spectral response?

I need to get the NDVI of a plant locally from specific reflectance on a micro controlled based context. The formula for the NDVI is: $$ NDVI = \frac{NIR-RED}{NIR+RED} $$ Where NIR is the near ...
0
votes
1answer
147 views

Through-hole solder sparking

Here is a simple example of what been happening to various pcbs when I play with them. I have an arduino powered by USB. Then a 5V and GND connected to a logic level shifter's HIGH and GND ...
0
votes
2answers
99 views

Detecting the luminosity of light [closed]

Edited: I'm making Arduino project which detects the luminosity (Brightness) of the room light (means AC current) adjust it to the accurate degree, there is an LED that connected to Arduino turns on ...
0
votes
2answers
93 views

Why is my oscilloscope reading jittering, and how might I fix it?

I've made a simple inverter circuit and I've read the voltage across the load resistor using a RIGOL DS1104 oscilloscope. Here is the link to the screen capture. I'm using a full-bridge inverter ...
1
vote
2answers
88 views

How can I sense a signal on a 12v automotive wire non invasively?

I'm working on a project where I need to sense if a circuit is in operation on a wide range of vehicles. My plan so far is a current sensing clamp, and an Arduino micro listening for the current draw ...
2
votes
1answer
74 views

Calculating the resistance for the base of a transistor

I'm building a circuit for my little niece's birthday (I'm already overdue with a couple of days). I started building it before I well understood enough about transistors and no I'm running a little ...
0
votes
1answer
86 views

How much current does an 1602 LCD draw? [closed]

I want to know how much current a 16x2 (1602) LCD draws when the backlight is OFF and ON? NB: My multimeter is broken.
0
votes
0answers
49 views

Arduino log file directly to file [migrated]

Hey I have problem because i need to read values and then save them in .txt file but Arduino doesn't have physical connection with my computer. It only has connection with computer using Ubuntu ...
0
votes
0answers
21 views

Controlling a L510 inverter with Arduino using RS-485

I'm trying to control a "IGBT Drive Inverter Motor Speed Regulator" model "L510-202-H1F-P A" with an Arduino. The manual for the inverter is here https://inverterdrive.com/file/Teco-L510-Manual-EN-v2 ...
0
votes
0answers
51 views

Driver for Ultrasonic Mister

I'm looking to build a circuit that can produce a 113 kHz square wave with an amplitude of 70-100 V and a variable duty cycle. I have recently brought this: https://www.aliexpress.com/item/20mm-...
0
votes
0answers
33 views

Low voltage IGBT based Impulse generator [closed]

Currently, I am working on IGBT based Impulse voltage generator with 60VDC. I made some simulation and I found the capacitor and pulse shaping network values but I have few doubts. 1)Which type of ...
0
votes
1answer
66 views

Why is my shift register circuit not working?

I would like to capture the state of some push buttons with a shift register (CD4014B). I am trying to troubleshoot and identify if the problem I'm having is hardware or software. Printing the byte ...
-1
votes
0answers
64 views

3.3v signal to drive 5v relay [duplicate]

I am reposting a question with more details, hope you will be kind enough to share you knowledge with me - I am currently playing around with a NodeMCU 1.0 - ESP8266 and having trouble switching on ...
-3
votes
1answer
66 views

which IDEs are available for Freertos with Stm32 IDE for Linux? [closed]

Is there any IDE available for Freertos or Stm32 for specifically only for Linux other than Keil uvision. because I found out that Keil uvision is the most stable IDEs available out there for embedded ...
0
votes
1answer
66 views

Help with Arduino loops please! [closed]

So I have an Arduino Uno and I've made a device to humidify my the enclosure for my Tortoise. The device consists of a temperature and humidity sensor, an LCD screen to display temperature and ...
4
votes
3answers
130 views

Detect drones passing through hula-hops

I host some drone races at times and I make gates with hula-hops. I fit some led stripes in there and they glow nicely. We ONLY run micro drones, F36, tinny whoop and those. And mostly indoors (...
-1
votes
0answers
51 views

Rotary Encoder without interrupts in Arduino

Actually, I am using a stepper motor, load cell, and rotary encoder to measure the elastic limit of different objects. I first run the motor code and encoder on two different Arduino and it that was ...