Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [arduino]

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

0
votes
1answer
86 views

What can I use to turn on a circuit at 5V?

I'd like to power an Arduino using a supercapacitor. I already have that part of the circuit figured out. But I want to charge the supercapacitor using an external power source, without the ...
0
votes
1answer
60 views

Servo motors twitching , arduino Mega [closed]

I am working on a school project: a robotic arm controlled by an Arduino Mega board, 6 servo motors: https://hobbyking.com/en_us/power-hd-lw-20mg-servo.html?___store=en_us 1 PC power supply (450W), ...
0
votes
3answers
76 views

Correct use of op-amp to amplify photodiode in reverse bias

So I have a photodiode in reverse bias, from which I intend to measure my pulse. Currently, my schematic looks as follows: simulate this circuit – Schematic created using CircuitLab Weirdly,...
0
votes
1answer
51 views

replacing smd atmega328p on a arduino nano clone

I accidentally blown up the original chip. :embrassed I have successfully soldered a new chip on but the MKII programmer won't enter programming mode. but I can clearly see the characterisic not ...
1
vote
1answer
61 views

Please check my DC / DC schematic. ST1S40

I want to make a voltage down converter to power my controller (Atmega328P). Input = 12V / Output = 5V (3A). As a converter, I use ST1S40. My connection diagram I took the circuit from datasheet, ...
0
votes
0answers
17 views

How to connect Arduino Lilypad USB to MicroSD breakout board? [duplicate]

I'm trying to connect the Arduino Lilypad USB to a MicroSD breakout board. I'm unsure which pins to use for the CS, DI, DO and CLK connections on the MicroSD board.
1
vote
1answer
66 views

Detecting Open Circuit, Short Circuit and Battery Reversal

I am facing various design challenges with a project that I am currently working on. I've been trying to figure out a way to build a circuit that detects open circuit, short circuit, and battery ...
0
votes
1answer
50 views

Connection For simulation touch using 1ch relay

http://gameautomators.com/book/Electronics/4-simulation.html Hi here is a reference to make a touch simulation with rpi and 1ch relay I can't understand how to connect gpios with relay. There are ...
1
vote
1answer
64 views

IR control with Darlington Transistor ULN2003A

I need a simple circuit to control a IR device. I'm quite a newbie with electronics so I would like to know if this circuit is correct because seems is not working. These are the datasheets of IR ...
0
votes
1answer
59 views

dc motor, hall sensor 10-20VDC to arduino

I have a linear actuator with a brushed DC motor with 2 hall sensors. I intent to use the sensors to monitor the position of the actuator. The specifications of the hall sensors are as follows: Hall ...
-1
votes
1answer
105 views

Voice encryption over TRRS headphones

-- Edit 2 --- This question is different from Connect STM32 BLUEPILL to the TRRS connector on the computer But just in case for not falling into double posting I deleted that post. (This post hes ...
0
votes
1answer
43 views

Evaluation A/D and D/A converter

If I need to read and write data over TRRS to and from headphone (i.e. I read from standard (iphone/galaxy) headphone mic. and write to standard headphone earphones). This is a schema of what I want ...
1
vote
1answer
52 views

Interfacing AD7811 ADC with Arduino over SPI

TL;DR: I am not getting the correct values back from the AD7811 ADC. I am giving the ADC an input from my benchtop PSU (Tenma 72-2540) into analog input 1, and getting various (and always wildly ...
0
votes
3answers
80 views

How does an IR LED turn on and how can I test to see if its not broken?

I'm an electronics beginner. Does an IR LED turn on like how regular LEDs turn on or does it only turn on when you've assigned a specific code for it to transmit? The reason why I ask: I bought ...
0
votes
1answer
33 views

Doppler frequency formula (for HB100)

I have a question about the formula provided on the application notes of the HB100 sensor. It is: $$f_d = 2v \frac{f_t}c\cos(\vartheta)$$ where \$f_d\$ is the doppler frequency, \$v\$ the velocity of ...
0
votes
1answer
49 views

Arduino and DAC

I have programmed an Arduino to control a DAC, generated signal control the current of an LED via a LT1206. Whenever I plug in the power, before Arduino starts, the LED starts to blink because it ...
1
vote
0answers
30 views

using ultrasonic sonar and mist maker together

I have made a cold steam bucket (ultrasonic mist maker). now i want to add automatic water level indication system for it using ultrasonic sonar module. i want to know if both mist maker ultrasonic ...
0
votes
1answer
44 views

How capacitor values are determined in this circuit

I am following the course on control systems from edx. I have this circuit as part of practical exercise. I would like to understand how the capacitor values were determined in this circuit The 47uF ...
0
votes
1answer
56 views

Deal with DC offset

I have STM32 BluePill and Teensy 3.2 , they both read analog 0 < x < 3.3V. I want to read earphone microphone sound but the mic produce +-2.5V (with ~200mA, but this is a different problem). ...
2
votes
4answers
501 views

Photodiode almost no mV at analog port

So I have bought a photodiode, which I intend to hook up to the analog port of my Arduino, so that I can measure differences in the light that the photodiode picks up. I realized, that when I don't ...
0
votes
1answer
48 views

How to read high impedance on pin Arduino?

The goal is to catch an AC leak. For these purposes, I use a measuring transformer (RCMB121). When there is no leakage, the output contacts are low (GND). If an accident occurs, the contacts go into a ...
0
votes
1answer
35 views

Position of leds in the RX/TX portion of an arduino compatible

Given the following circuit , electrically speaking makes any difference the position of leds? I know R8 and R9 are used to allow the override of the RX/TX pins if any other device is connected, does ...
0
votes
1answer
33 views

Arduino remote IRsend undefined reference error

I'm trying to use Arduino to transmit a code. I keep getting an error upon compiling. After tons of research, i couldn't find a solution. Can someone please see what i'm doing wrong? My code: <...
0
votes
1answer
39 views

Start ESP (Wemos D1) for short amount of time by pressing a button (no deep sleep)

How can I let an Wemos D1 boot on a button click, letting it execute an action and then shut down. I would like it to be wireless so it can be very flexible, and would love to not have to worry about ...
0
votes
2answers
49 views

is the intel quark capable of running an opencv webcam unity application for linux? [closed]

I built a fairly simple application in Unity that uses a webcam and opencv to overlay graphics in realtime to a user's face. I am looking for a low cost microcontroller/computer to run the ...
0
votes
1answer
32 views

Problems with Stepper Motor & SN754410

I am using a stepper motor for a project, it is the first time I've used one. The internet said it was very simple and easy but that's not true for me. I bought this motor from digikey https://www....
4
votes
0answers
92 views

Please help with my custom ATMega328 PCB [closed]

I created a PCB for my newest Arduino project and its driving me mad by now. I am through several PCB variations and tried connecting to it (via FTDI first - then) via ISP but I fail every time and in ...
0
votes
1answer
51 views

Series circuit LED controlled by Arduino schematic question

I'm currently making a project with multiple series circuits to PWM control multiple LEDs. I have figured out how to make it work with a transistor, however I was curious if this way would work as ...
2
votes
2answers
74 views

Unusual behavior when controlling a Button Matrix

I have a 4x4 matrix for 16 buttons. Each row/column is directly connected to the pins of an unknown microcontroller. When I connect the pins directly to each other, the microcontroller behaves ...
1
vote
1answer
35 views

How to wire DotStar LED strip with 6 wires at the start of the strip

I bought some of these LEDs: They have six wires at the start of the LED strip. I thought that perhaps the separate red and black wires were to power the LEDs, and that, for the 4 wire JST, the black ...
0
votes
1answer
39 views

Vertical Farm Automation

I am building a system to automate a vertical farm (specifically watering, lighting, and drying) and am having trouble choosing between a wired or wireless system architecture. The farm is arranged ...
0
votes
2answers
27 views

Using a Relay with SMPS as load leads to contact welding after keeping energized for sometime

I am using a relay SRD-5VDC-SL-C(generic module made for diy projects) to control AC current going to my SMPS(120-300v AC to 12V, 2A DC) driving my LED strip. The relay is controlled by a Lolin ...
-1
votes
1answer
40 views

Power Management

I am supplying power to a Arduino Uno that draws 45mA of current and a sensor that draws 20mA with a 9 Volt battery(ampere for battery is 550 mAh. How much power is the whole system consuming? I am ...
1
vote
1answer
41 views

Optoisolator Not Switching

I’m working on a university project that involves switching a relay using an ILD213T optoisolator. The optoisolator is driven directly by an ATmega328p. I had calculated the required current limiting ...
-5
votes
2answers
79 views

How to connect my Sony camera to an UNO ATMega238p Arduino? [closed]

I saw a cool project online where they had a little camera connected to an Arduino with a motion sensor, the camera takes pictures whenever the sensor gets activated. So, I'm trying to build the same ...
0
votes
2answers
65 views

Better resolution with photodiode (LTR-536AD)

I want to build something like a fog-sensor. I'm using a laser and on the other end (~20m) I have a LTR-536AD photodiode. I hooked the photodiode to an arduino and was monitoring the voltage. My ...
0
votes
1answer
78 views

Correct use of transimpedance amp

So I realized that it might become a necessity for me to use a transimpedance amplifier for a pulse watch that I intend to make. Some background: The pulse watch shoots light at 940 and 660nm at ...
0
votes
1answer
74 views

Control the relay using an arduino

I'm trying to make a DIY smart socket. Is it possible to control the relay with an Arduino? Maybe replace the controller with the Arduino? Can I use the ribbon cable Out, Ground and VCC pins do to ...
1
vote
2answers
127 views

Controlling Speaker Output with Transistors

I am awfully new to circuit design and a little confused on some of the things I can and cannot do here, so please bear with me. In a simple Arduino project, I am trying to control the output of an ...
0
votes
1answer
56 views

Does this photodiode need an operational amplifier?

I'm trying to make a circuit for a pulse watch, which should be capable of measuring blood SpO2. I use 2 LEDs for each wavelength (respectively 660nm and 940nm) to shine at the upper wrist. The ...
-3
votes
1answer
88 views

What if I connected +5V from one source and GND from other to arduino [closed]

I'm just asking... What if I connected +5V from one source and GND from other to Arduino Will it work? EDIT simulate this circuit – Schematic created using CircuitLab Will it work? or ...
1
vote
0answers
46 views

Connecting door strike to relay

First of all I know there are many similar questions answered but I'm still a bit unsure on why my current set up doesn't work. I'm really outside my area of expertise so be kind. This is what I have:...
0
votes
1answer
36 views

Can't upload sketch to my custom designed arduino Uno

I'm having problems uploading sketches to my custom arduino uno design. I have a ttl to usb based on the ch340 and at the same time I have a RS485 transcriber both conected to the atmega328 serial ...
-1
votes
1answer
49 views

Raspberry pi zero + Arduino Lilypad

I was hoping to make a gesture+flex sensor controlled glove using an Arduino Lilypad and Raspberry Pi Zero W. I was wondering how I could connect the two boards to communicate between them? This is ...
0
votes
1answer
50 views

Drive 10 piezo buzzer from micro controler simultaneously and independently

I'm looking for a solution to drive simultaneously 10 piezo buzzer from teensy. I'm aware about the limitations of the number of internal timers so I'm looking for an external chip that would enable ...
0
votes
1answer
27 views

Unable to supply FONA 32u4 3.5 v through circuit

I am relatively inexperienced when it comes to circuitry and electronics. However I am trying to create a simple device in which with a press of a button, the device turns on and calls a specific ...
0
votes
3answers
108 views

Switching Relay with NPN and PNP transistors

I'm designing a locker system using Arduino. Due to system requirement, two IOs will be used control the relay, and only when two IOs are ON, then the relay will be triggered. PNP = BC807 NPN = ...
0
votes
3answers
52 views

Constant Current Load fails to recover after setting load to zero

I'm trying to design a Constant Current load for testing battery cells using the TLC070 Op Amp (what I happen to have on hand) and a low pass filtered (150Ohm + 470uF cap) PWM input from an Ardiuno. ...
1
vote
1answer
124 views

Arduino breakout schematic for FDS100 Photodiode

This is the first time I'm drawing a schematic, thus why this question seeks to get clarification from you experienced engineers :-) A little background information: I'm trying to draw a circuit ...
-1
votes
0answers
31 views

Help with OpAmp amplification of a sensor in Arduino Analog Read [duplicate]

I do not mean to spam this forum with elementary questions, but I am not an EE and need a constructive opinion on how to apply a Amplifier with sensors . My circuit is a photo-diode from which I ...