Embedded Stuff

3 answers

Controlling AC mains using arduino and removing control easily

I am planning to for an arduino to read status of a switch, and accordingly switch on and off AC appliance, for a demo purpose. I want to add a feature to it of easy recovery to manual switch control. …

1 answer

What is the speed of an electric spark/arc in vacuum?

I am just curious about the nature of an electric spark, how fast are the electrons moving? Will these electrons slow down when the spark occurs through a dielectric? (e.g., air)

4 answers

Is it possible to generate random numbers using physical sensors?

I've heard about people using light sensors, geiger counters, and other physical sensors to generate random numbers, but I'm skeptical. Is there really a way to generate random numbers from taking …

1 answer

Reading from serial port in c

I'm trying to read from arduino (who's sending char '4' constantly) with xbee. I have tried writing from pc to arduino and it works, so the connection is correct. When I execute de following code, …

1 answers | 2 hours ago by danespcha on Stack Overflow stackoverflow.com
0 answers

Xbee Router-Coordinator Configuration S2

I'm trying to set up a very basic network using 2 Xbee modules. One as Coordinator and the other as Router. The Modem version is XB24-ZB The coordinator has the following serial number: ...

1 answer

What's causing the effect of salt in voltage arcs?

I just came across this video demonstrating that salt increases length of voltage arcs. There is no explanation which leaves me quite confused. Does the salt decompose during the process?

1 answer

USB interface with STM32

I'm experimenting with native USB in STM32. I've not found any "step by step", or a little more well structured tutorial, how to implement CDC or mass storage for example. I've found some examples, …

1 answer

Capacitor charging, work done by battery on changing polarity

A uncharged capacitor $C$ is connected to a battery with potential $V$. It becomes fully charged and has a charge $Q=CV$ stored on it. Now the polarity of the battery is reversed. The capacitor will …

1 answer

MFRC522 on Beaglebone Black

I am trying to get my RC522 to work on the BBB. It works great on my Arduino which is well documented e.g. here or here. My only requirement is to read the serial # of cards which are Mifare S50. I …

1 answer

Creating Real-Time Graphs in Android App for Bluetooth Pulse Rate Sensor

I'm currently developing an Android Application which connects via Bluetooth Low Energy to an Arduino which has the nRF8001 Bluetooth Low Energy Module with a connect the SEN-11574 Pulse Rate Sensor …

1 answer

Error with sending Ints/Strings from Python via PySerial

this is my first post on this forum so hello all :) I'm trying to build a CPU Monitor with Python and Arduino, While Arduino works fine im having problems with Python. My Problem is that I cant get …

1 answers | 10 hours ago by Fridoku on Stack Overflow stackoverflow.com
1 answer

Is it possible to use induction ampermeter to measure power consumption of electric water heater and dryer?

I hope this practical question is not OT and not too trivial for this forum. I am renting an apartment in a duplex with a shared water heater and dryer. Turns out, both water heater and the dryer are …

1 answer

Is there a surface charge density?

Consider a dielectric sphere placed within a dielctric medium. There is a uniform electric field $E_0$ present throughout in the medium. Would there be surface charge on the sphere?

0 answers

blink an LED for 5seconds and stay on for 15minutes

I want my program to blink for 5 seconds if the button is pressed, and when the button is released, the LED will stay on for 15 minutes. So far I have done the debouncing, but when I place the syntax …

1 answer

Electrical Analog of a Chain of Springs

I'm trying to wrap my head around the Force $\rightarrow$ Voltage analogy between mechanical and electrical systems. I have a mechanical system where masses are connected by springs in series, and ...

2 answers

Designing an ABBA circuit (3 input, 2 output) inputs: (GND, +V, Logic)

I'm working on a relatively simple Arduino project and want to reach an elegant solution for a circuit. I'm not sure if there is an existing IC for what I want to do, but here is a diagram for what …

0 answers

Arduino VirtualWire Rf module Send a String

Sorry if my post is not well formatted'm new in here. /* SimpleSend This sketch transmits a short text message using the VirtualWire library connect the Transmitter data pin to Arduino …

1 answer

Detect alternating current using one contact only and arduino analog input

I am trying to setup an arduino so it can detect an AC where it only has access to one pole. (kind of like these "electricians screwdrivers" that you put in one of the connections of an electric ...

3 answers

Excessively high temperature reading with LM35

I am really new to electronics and I am just experimenting at the moment with a breadboard. My question here is related to the LM35 temperature sensor and Arduino micro controller. I am getting a ...

0 answers

Multiple nrf24l01, shared power, ripple/interference, DSO screenshot provided

I've got this circuit with 3x atmega328 & nrf24l01+ running off shared power supply, either 2x AA battery or 3v3 reg. It acts as a repeater, and depending on the origin of the message and the ...

1 answer

Does the HC-05 bluetooth device support AVRCP commands?

I am trying to control the android music player from an Arduino with an HC-05 Bluetooth module. I have successfully paired them in serial mode but have been unable to find any means to connect them …

1 answers | 19 hours ago by user3495967 on Stack Overflow stackoverflow.com
0 answers

Electrical field of the coil

Take the case of two coils, first one connected to alternating current supply, and the second one connected to load. First coil creates magnetic field, and electric field is reduced by anti-emf ...

1 answer

Webservice C# JSON to Arduino

I have a project in Microsoft Visual Studio C# and I have to send JSON data to my Arduino via Ehternet Shield. This is how it works: Is it possible? How to do it?

1 answers | 20 hours ago by Thiago on Stack Overflow stackoverflow.com
0 answers

Arduino Leonardo Upload issue with ubuntu 14.04

I got a bare conductive board ( which is based on arduino leonardo ) . I was trying to upload a blink sketch using arduion 1.5.7. But its always failing and here is the log. I never work a leonardo …

2 answers

Can I embed this charger in a project?

I have been attempting to create a portable arduino gaming system. While I have tried normal 'AA' or 'AAA' batteries, they are too large, so have decided to use a lipo battery. I now have this, but I …

0 answers

Arduino Extract String inside HEX value

I have a Serial device that sends to me HEX arrays through Serial, i get this : 01 10 01 15 43 20 f4 5d This is how i get the Chars from Serial: if(Serial3.available()){ int j = ...

1 answer

Normal modes of two parallel $LC$ oscillators coupled via mutual inductance

Consider the circuit shown below. The two LC circuits are arranged in such a way that their mutual inductance M results in a coupling between the currents flowing in the two circuits. Find the …

0 answers

I cannot find fritzing 2x3 pin header

How can I get an 2x3 pin header (used for ISP programming for atmega, for example), to appear in Fritzing? I cannot find it in the parts list.

1 answer

Arduino dies after activating a 5th led

I have an Arduino Uno, using a MAX7219 to control a 8x8 Bi-color led matrix. The problem however, is that upon activating a 5th led in the matrix, the unit "dies", in lack of a better word. I can ...

1 answer

Voltage across an inductor contradicts Lenz's law?

Imagine a simple circuit consisting of an alternating current source connected to an inductor. Assume they are connected in the following fashion: AC source - terminal A - Inductor - terminal B - AC …

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