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Questions tagged [arduino]

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

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0answers
39 views

Power Arduino from MicroSD host and more

There are a lot of cheap MicroSD port extender flex ribbons from China. These things extend the MicroSD port quite a lot. I thought it would be cool to adapt these to power an Arduino from a phones ...
1
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2answers
110 views

Does this prototype match the schematic?

I'm following this project which shows how to make an OpenTherm Adapter for an Arduino. It includes this schematic: Along with this simplistic PCB diagram: I am now in the process of making my own ...
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2answers
76 views

Choosing a resistor for connecting a bipolar transistor

I need to run some LEDs using Arduino. The total current consumption is about 190 mA. For these purposes, I found a bipolar transistor PMBT2369 (Nexperia). Transistor characteristics: - Maximum ...
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1answer
73 views

Arduino serial communication hacking

I recently bought a Chines massaging chair hoping i can intercept the serial communication between its wired remote and the chair itself, I've cut the wire and connect the Rxd and Txd of the chair to ...
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2answers
77 views

Extend number of PWM pins on an arduino?

How do I extend the number of PWM pins on an Arduino without using software solutions, I need 32 to drive 32 mosfets? Thanks!
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1answer
98 views

PT100 sensor for measuring liquid resin, fully submerged

Edited Link to Pt100 sensor (That's the best i could do) https://www.intech.co.nz/products/temperature/mrh.html Link to ESP8266 datasheet http://www.handsontec.com/pdf_learn/esp8266-V10.pdf ...
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1answer
127 views

How to connect LED driver to arduino

How do I connect 2 of these LED drivers to Arduino? http://www.starchips.com.tw/pdf/datasheet/SCT2024V01_03.pdf This is what I have so far, im connecting each output to a N-channel mosfet. Im not ...
1
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1answer
98 views

Do i need a LED driver to drive 32 mosfets? [closed]

Im trying to use two 16 channel LED drivers to drive 32 mosfets, im not understanding the datasheet about current sinking, maximum voltages etc. Are they meant to drive the LEDs by themselves? ...
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0answers
36 views

LCD 18 (6 x3 ) Pinout without Datasheet AW -60i LCM V4.1

I have this (18 X 3) LCD Pins, I need help to find the Datasheet or the pinout for it. AW -60i LCM V4.1
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0answers
43 views

mosfet as a switch on arduino pin and xbee explorer board 5v

I have looked at various examples of MOSFET switches but I am not knowledgeable enough to adapt what I see to what I would like.... I want to have a pin on my 5 volt Arduino Micro board turn on or off ...
0
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1answer
67 views

Tactile touch button design using pull up resistor

As you can see on my github https://github.com/mancio/Volante-The-Gamepad I'm designing a gamepad with analog axes and digital touch buttons using pull-up resistors My pull-up resistor switch works ...
1
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2answers
73 views

ORing for Arduino Mini Pro

I am attempting to make an alarm on AC main failure based on Arduino Mini Pro. The idea is that when AC main failure happens the Arduino Mini Pro shall wake up and periodically "beep" between "...
0
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1answer
74 views

Arduino and 3W LED sharing the same power source, is it possible and how?

I've built a remote control for my 3W power LED with an Arduino UNO and I'm powering the Arduino with a USB cable and the LED with 4x AA NiMh batteries (1.2V). Is it possible to power both my Arduino ...
1
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1answer
85 views

CAN Controller + PIC32

I have been trying to design a functional board which combines the hardware of the Elecrow Arduino Uno CAN bus shield with a microcontroller board, which functions like an Arduino except with ...
2
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1answer
186 views

When I write data to a BLE Characteristic (FFE1) to send data over bluetooth, is the data encrypted?

I have a very simple circuit which includes a HM-10 that exposes a CC2541 Bluetooth device. simulate this circuit – Schematic created using CircuitLab It's basically just hooked up to power ...
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2answers
60 views

Choosing the ground for circuit

Can the GND pin of the Arduino UNO be used as a ground instead of the negative terminal of a battery while using a battery as the power source? If no, do we have the liberty to choose our ground for ...
0
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1answer
100 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
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1answer
78 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), ...
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3answers
96 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,...
1
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1answer
54 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
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1answer
64 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, ...
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0answers
18 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.
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2answers
219 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
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1answer
56 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
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1answer
74 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
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1answer
95 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 ...
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1answer
117 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
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1answer
58 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
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1answer
62 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
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3answers
84 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
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1answer
40 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
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1answer
59 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
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0answers
58 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
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1answer
46 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
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1answer
69 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
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4answers
520 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
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1answer
58 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
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1answer
37 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
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1answer
40 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
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1answer
46 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
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2answers
53 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
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1answer
42 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
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0answers
107 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
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1answer
54 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
79 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
44 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 ...
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1answer
47 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 ...
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2answers
37 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 ...
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votes
1answer
42 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
46 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 ...