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0
votes
5answers
101 views

Appropriate relay for water heater rated for 220VAC/1500W

I've created a complete hardware platform using a Raspberry Pi as master/controller, an Arduino nano and two RF24l01 transceivers, which should control some household electrical appliances. The ...
0
votes
1answer
33 views

How many DS18B20 temperature sensors can I connect to one bus arduino?

How many temperature sensors can I connect to one bus without losing accuracy.Can I use for example 50 sensors to one bus? Should I change the resistor when I connect too many sensors? Here is the ...
0
votes
1answer
32 views

Input and output relation of ACS712 Hall effect current Sensor

ACS712 works by the use of the hall effect principle. When i went through the datasheet, i found out that the relation between input current and output voltage is varied largely ie. 66 mv/A to 185 mv/...
0
votes
0answers
31 views

Sensing a light object on a plane [on hold]

I'm attempting to complete a project involving a microcontroller and some sensors. I want to detect that a very light object (20 grams) is touching a place at four different points of contact. Some ...
1
vote
1answer
100 views

A question on PWM frequency of a DC motor

I'm planning to pwm-control four of the following motors by a single ArduinoUno: http://uk.rs-online.com/web/p/axial-fans/8179151/ For some reason the nearest pwm frequency I can set is 31kHz. The ...
0
votes
0answers
21 views

How to prevent Arduino Uno to change USB port [migrated]

I have an Arduino Uno connected through USB to my Ubuntu PC (one USB hub in between). I run a program that communicate through serial and use then the port ...
0
votes
0answers
23 views

How to communicate from Python to Arduino Softserial [migrated]

That is driving me nuts so I need your help. Master : PC with Ubuntu, a USB to serial converter (chipset CP2102), connected to Arduino Uno Pin 10, 11 and GND. The Arduino Uno is plugged in the same ...
0
votes
2answers
54 views

Arduino - Pulses get unstable when updating PWM duty-cycle

I'm trying to obtain stable pulse trains when adjusting the duty cycles wth an Arduino Uno board. In my actual project I need to use 4 adjustable PWM output pins at a fixed 25kHz frequency to control ...
0
votes
0answers
26 views

Bluetooth Socket connection with HM-10

I'm using HM-10 4.0 Bluetooth module. I have written an android app. Upon starting the app it will discover nearby bluetooth devices. If it finds my HM-10 Bluetooth module then it pairs with HM-10 ...
0
votes
3answers
61 views

my arduino is working slowly in this function [on hold]

my project is designing an ECU (engine control unit ) for a formuala car with my team , and I'm using arduino , arduino is connected to 6 sensors attached to the car such as o2 sensor map , this 6 ...
-1
votes
0answers
20 views

Mirroring display content of SSD1306 OLED using Adafruit library for Arduino [on hold]

I am using Adafruit Library for SSD1306 and wanted to mirror the content displayed to use the device as Heads Up Display (HUD). I tried searching online to see if I can tweak the library for ...
0
votes
2answers
106 views

Attiny85, reading analog values from PIN3, reports 654 on idle?

At first, I am not a hardware professional (starter) so be kind please. I try to reuse a DENON operation board of a DVD-player with 9 buttons with a Attiny85 Digispark clone connected to PIN3 (see ...
3
votes
2answers
111 views

A visible light communication question concerning a preamble sequence

I have a question about preamble and preamble breaker. I am implementing a simple visible light communication using arduino. I have used a Manchester encoding scheme. While I have understood that a ...
1
vote
2answers
114 views

Why does the accuracy of my camera drop when I start using no-ops as delays?

I'm using an Arduino Mega to run three TSL1401R-LF Linear Scan Cameras in parallel. I got everything working and the camera were giving me different results based on how much light was hitting them (i....
-1
votes
1answer
41 views

Connecting Cathod Commond RGB Leds in parallel with arduino

I'm just starting with arduino, and want to light up 2 RGB leds (common cathode), and just think that the only thing I nedd was connecting them in parallel, no extra parts (my mistake), then I read ...
-1
votes
0answers
31 views

Is there an open source wlan router supporting dd-wrt [on hold]

My router is not working anymore and I'have two options either to buy a new one, which is not very fancy or use my PCB designing skill and to make one by myself. Is there an open source wlan router ...
-3
votes
0answers
30 views

Arduino BLE Receiver [on hold]

I'm trying to develop a solution for an outdoor fair with no access to electricity. I will give each attendant an ID with an Estimote Sticker. What I'm trying to do is add a device that costs less ...
-3
votes
1answer
75 views

What are all these pins on the DS1307 RTC for?

I recently ordered a DS1307 RTC from ebay. Before, I did some research and found out that you only need 4 pins for it: Vcc, GND, SDA, and SCL. The one I got has many other pins like DS, BAT, SQ(I read ...
0
votes
2answers
61 views

Long range sensor readings in a star network with Arduino

I'm planning a project that requires me to have around a dozen temperature and humidity sensors placed around the house and the yard. These would connect to a central Arduino in the house that would ...
-6
votes
0answers
26 views

How to connect an arduino with sim300 and a seperate gps module? [migrated]

i am trying to connect an arduino with sim300 and gps module to upload data directly into a database on my localhost using gprs of the sim inserted.I am not able to interface the seperate gps and gsm ...
-3
votes
0answers
18 views

Lm386 audio amplifier module microphone connection [closed]

How can I get the module to pick up the microphone that is connected to it? The brown wire is ground to battery, green wire is ground to microphone, yellow is audio in, orange is the battery in. ...
0
votes
0answers
35 views

Comparing PID_v1.h in Arduino to PID(z) in Simulink

I am trying to implement model-based controllers in Arduino. I have explored several control systems in Simulink and now I want to see if I can replicate those simulations in Arduino. For instance, ...
-1
votes
0answers
24 views

Arduino communication via 2.4GHz band [closed]

I want to make my Arduino's communicate with my laptop,phone,and with each other.I want to use the 2.4GHz band because every device(PC,tablet,etc.)can connect to it,it's fast and it can travel a long ...
-1
votes
0answers
12 views

interface arduino with lcd to work as oscolliscope [closed]

in my project ... l get a sin wave from arduino due and i want to connect it with tft lcd work as an oscollicope to show my signal. so i want to ask ..do i need a shield for arduino ? ... what do i ...
0
votes
1answer
58 views

Arduino solar panel watt meter values reading 0's

I've been building a Arduino Watt meter for the past few weeks for a solar panel, and have successfully measured voltage and current separately. However I need to know both to calculate watts but can'...
1
vote
0answers
39 views

Arduino - External Power not working properly [migrated]

I am a newbie to Arduino and created my first project. The project is using a Sharp short range sensor and a 7 seg LED board (http://embedded-lab.com/blog/new-version-of-max7219-based-4-digit-serial-...
0
votes
2answers
31 views

QRE1113 breakout with IR LED control

I'm interested in the following IR sensor breakout board with the QRE1113: https://www.sparkfun.com/products/9454 However, I would like to control the LED (on/off, PWM if possible). Should I ...
0
votes
0answers
27 views

Arduino Leonardo clone programming problem [migrated]

I have made my own Arduino Leonardo clone using the Atmega32u4 as per attached schematic. Board operates at 5V, 16MHz. Power rails are clean. I burned the Arduino bootloader onto the device as per ...
0
votes
1answer
97 views

Best way to get 5v or 12v or 0v from arduino pin [closed]

Concerning the answer to this question explained in the link "Best way to get +5V or +12V or 0V from arduino pin" I am at very basic level of electronics because I am in first semester of Electronics ...
11
votes
1answer
981 views

Weird behavior of 'soundcard' oscilloscope

This is what I did I expected a nice square wave on my soundcard oscilloscope software but I'm getting this What is happening ?
0
votes
1answer
62 views

How to connect a headphone jack to this lm386 [closed]

I would like to attach a headphone jack to this board but I'm a bit confused as to how since the jacks I find have 5 pins but this only has 2 places for the headphone cables. Thank you in advance ...
0
votes
0answers
9 views

Aruino pro mini not accepting new code [migrated]

I recently purchased an Arduino pro mini from Amazon, and a ch340g serial adaptor to program it. When I first used it, I only used the simple blink program, just editing the delays. This worked great, ...
-1
votes
2answers
108 views

Using an Arduino (If Needed) to Charge 18650 Battery [closed]

I am looking for a way to charge 18650 battery with an Arduino (If needed) as simple as possible. I have seen tutorials where you have to buy 10 diffident parts. I just want the simple (But wont ...
-3
votes
1answer
37 views

is there an Arduino Based Quadcopter? [closed]

i have been looking for an Arduino based quadcopter to buy and edit for another project, but no way ; is there any store where I can buy one ? thanks.
-12
votes
0answers
57 views

Upgrading Arduino board to support 220V of current [closed]

I was working on inverter-like device but only a bit advanced. I thought to make it a little less time consuming by using Arduino Mega 2560 board schematic and design, availabe as example in Eagle By ...
0
votes
3answers
69 views

Convert PWM to Analog using a DAC chip in order to emulate a Potentiometer for audio

I'm trying to control audio level/gain (from line or amplified signal) using an Arduino. I do not want to use SPI, for this project I can only use the PWM outputs, thus I do not want to use a digital ...
0
votes
0answers
39 views

Particle Electron to RS232 Serial gibberish [migrated]

I've spent all day trying to monitor serial console output of a router. I'm using an "ebay" MAX3232 RS232 to TTL converter connecting only GND, TX and RX to the Electron. Trying to simply monitor the ...
1
vote
2answers
82 views

Issues with NPN Transistors and RGB LEDs (Common Anode)

I have a question regarding the use of NPN transistors in an RGB LED (common anode) circuit connected to an Arduino Uno. I have spent the past several months developing LED color control software that ...
0
votes
2answers
132 views

Modifiying variable inside of Interrupt vector. AVR

My question is again about modifying variables inside the ISR. If the variable used only inside of ISR, I don't have to declare it as volatile, right? After some researching, I figured out that ...
0
votes
2answers
100 views

Mosfet not passing enough current using a microcontroller and 2 power supply

I have made this circuit: Ignore "high voltage circuit" is not used. It's a prototype built in a breadboard with jumpers, and i have a problem with the mosfet "IRL540N", is not passing the optimal ...
0
votes
2answers
147 views

What will increase output volume (dB) on a Piezo Transducer?

I need to achieve 110dB at 25khz from a Piezo Transducer. According to the datasheet, the resonant frequency of the Piezo is 25khz and at 10 vrms it will produce 110dB. I will be using an ...
0
votes
0answers
44 views

8x8 switched diode matrix not behaving

I'm trying to read a matrix of switches. Attached is the circuit I've designed, the pertinent section being on the right driven by the 4041s. I'm using 1N4148 diodes. What I've found is that if I ...
0
votes
0answers
13 views

Unable to create a desired periodic signal with Arduino Mega 2560 and DAC0808 [migrated]

I write the code to produce the periodic signal by using arduino and DAC0808 where i turn on the respectively pins of PORTA and by using a logic in iterative manner, i created the periodic signal. But ...
-5
votes
0answers
30 views

how can i get a maximum frequency for arduino due? [migrated]

i have a project to get square ,sin and sawtooth from arduino due ,and i get them from dac ports. but when i tried them on oscolliscope i found the output frequency only 500 hz and i want it in Mhz . ...
0
votes
1answer
92 views

Arduino 4N35 input

I trying to interface the arduino digital pins through an optoconnector attached to an LED of a consumer electronic device. I have bought the recommended component for this. Before I would even get ...
0
votes
0answers
41 views

Basic Question - ESP8266 Board Pins [migrated]

I have an embarrassingly simple question. My experience to date has been limited to Arduino Uno + Wifi101. I bought an ESP8266 and noticed that the GPIO pins don't match the printed numbers on the ...