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1answer
42 views

Why is the voltage across a Zener diode so dependent on current?

I was going to use a 3.3V Zener diode to protect the analog inputs of an Arduino Due, but I found that the voltage drop across it was only 2V. So I tested connecting it to my power source with a ...
0
votes
1answer
44 views

making EMG electrodes

For a bionic hand controlled by EMG signal, I need EMG electrodes. The problem is that I searched everywhere for suitable electrodes but I couldn't find any. Can you suggest how to build them myself ...
-3
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0answers
24 views

how to connect a bluetooth headset to arduino along with ultra sound [on hold]

I want to know the procedure of connecting a Bluetooth headset to an arduino. I want to connect 3 ultrasound 1 speed detector with the arduino. How to set a voice clip on arduino for headset. As an ...
0
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0answers
33 views

Beverage Sensor For Arduino [on hold]

I'm planning to detect content of a beverage. Say amount of caffeine in a mug of coffee or amount of alcohol in a mug of beer, something like what Vessyl does. I'm not exactly looking for circuit but ...
0
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0answers
28 views

beer pong cup sensing pod IR RGB led using arduino [on hold]

I want to build a beer pong table that has LEDs. I need some help in building the RGB pods, so that when a cup is on the pod, it changes to green and when the cup is out it turns red. How should I ...
1
vote
0answers
41 views

Two-wire communication (I2C) between Arduino Micros [migrated]

I am attempting to communicate data via I2C between two Arduino Micros, but can't seem to get the "slave" device to detect a Wire.onRecieve() event. Per the specification on this site ...
1
vote
0answers
36 views

How to output kitchen scale voltage or actual weight value to an Arduino or Raspberry Pi? [on hold]

I want my kitchen scale to talk to either an Arduino or Raspberry Pi because I think I could connect the arduino or pi to the internet and then start keeping data on various things in the kitchen I'm ...
0
votes
1answer
56 views

Creating a common ground

I need to drive a 12 volt motor with a signal from an arduino. For this, I connect the ground of the arduino to the ground of the battery eliminator creating a common ground. I then connect the ...
-1
votes
0answers
12 views

How to upload one code inot a number of Arduino atonce? [migrated]

I am trying to Upload a single code in a number of Arduino one by one.But it is time consuming.So I want is, is there any way to upload the code at once to multiple Arduino? 1.I have tried as ...
1
vote
2answers
66 views

Register LED blink without reference to ground

I'm trying to trigger an Arduino pin based solely on the voltage across a blinking LED. I.e., when the LED blinks, I want to register the blink with the Arduino input pin. Unfortunately, I only have ...
0
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0answers
11 views

PID control arduino [migrated]

I am hooking up an accelerometer to an arduino uno and running it through this pid controller. However the output isnt going to my setpoint. When i move the accelerometer back and forth the data goes ...
-1
votes
2answers
91 views

Cumulative LEDs

For a better explanation let's think something like an equalizer bar Think one of these bars. The coloumn has 16levels from bottom to top. If the level 10's led need to light up then, the all levels ...
0
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0answers
18 views

Why MATLAB do not always read from serial port? [migrated]

I'm doing a project where I need to read and write serial data between MATLAB and Arduino. But MATLAB do not always successfully read data. I set baudrate 9600 and my serial setup is like this: ...
0
votes
0answers
21 views

Accessing configuration registers of OV7670 cam on i2c [migrated]

I am a new user of Aurdino and want to interface OV7670 camera with aurdino uno which uses i2c mode of communication.I want to check the configuration of the device control registers and set them as ...
3
votes
1answer
65 views

ATSAM3X8E: Custom Arduino Due Design

I'm currentlry doing a redesign of the Arduino Due board to include some additional features I need. Browsing through the Datasheet of the ATMSAM3X8E atmel chip, I noticed that the 12Mhz Oszillator ...
0
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0answers
50 views

What is more power efficient: GPRS or SMS for a GSM sim Arduino application?

I have a GSM shield for my Arduino and am wondering the most power efficient way to receive and send data from and to the cloud. The specific project I am looking to accomplish is starting my car ...
0
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0answers
44 views

4-Pin fan tach sensing gives weird results

I built a small setup to control a 4-Pin PC fan with my Arduino. Controlling the fan speed with PWN signalling works fine. But I can't get the tach readings right: The sense-cable from the fan is ...
0
votes
1answer
47 views

Connection between MDB Peripheral and Arduino

I'm working on making a custom vending machine controller using an Arduino as the master. The bill acceptor I'm using implements the MDB communication protocal, which is (I think) a variant of RS-485. ...
0
votes
1answer
47 views

Level shift from 5V to 3.3V (and vice versa) using 74HC4050N,652

Below you will find a link to the datasheet for 74HC4050N. My order I placed had a suffix of ",652" on that part, but I'm not sure what that number refers to. ...
0
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0answers
26 views

Weird characters in Serial Monitor and not functioning ESP8266 ESP-12e [closed]

I moved this question to http://arduino.stackexchange.com/questions/24573/weird-characters-in-serial-monitor-and-not-functioning-esp8266-esp-12e I did a bit of playing with my new ESP-12e, but ...
4
votes
4answers
4k views

Need help with use of LM358, microcontroller and +/- power supply

I have signal in 0-5V range and would like to amplify it to 0-10V. For that I am using LM358, but I have a bit of trouble with that. I have naively designed the circuit like so: I tried to supply ...
0
votes
1answer
48 views

PID controller stablizer application

I am wondering if a PID controller is the correct way to implement a stabilizer for a camera or any device. If I were to shake the device up and down and want to cancel out the movements by ...
0
votes
1answer
54 views

Running a Peltier directly from a transistor

New to post, but I come here often. So I am working on building a small fermentation chamber and i want to control the temperature using two Peltier's. One for hot and one for cold. I'm using two to ...
0
votes
1answer
71 views

PWM signals averaged or not

I am using analogWrite(PWM) from Arduino UNO to control the gates of 30N06L N-channel mosfets. The values of PWM are programmed such that it controls the current through the loads for my control ...
0
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0answers
42 views

Arduino MKR1000 Overheating problem… [closed]

I got a new Arduino MKR1000 board from World Arduino Challenge. It is working fine but seem to be WiFi shield is overheating when it is connected to USB. Am I the only one facing this problem?
0
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0answers
43 views

Arduino I/O Shield relay won't switch [migrated]

I have an Arduino Uno and the I/O Shield wired up and I'm trying to switch (i.e. engage) a relay on the I/O Shield, but nothing seems to be working. I've identified the input pins correctly and am ...
0
votes
0answers
38 views

How to bootload a atmega328-pu using arduino uno? [migrated]

I have some Atmega328-Pu micro-controllers without boot-loader program. Now I need to burn boot-loader to them all. I have two arduino uno boards having Atmega328 P-Pu micro-controllers on board. I ...
1
vote
1answer
108 views

Relay Feedback Problem

I am a computer science student working on a project for my Diploma and I am building a DIY PDU, I thought building something would be a lot funner then programming a website like 90% of the class ...
-1
votes
0answers
34 views

ESP8266 IFTTT failing [closed]

I have a setup which uses the ESP8266 12E and it opens a web server at a specific port 200. I have used the port forwarding to route the incoming data to this server .And I have used the duckdns to ...
0
votes
1answer
44 views

ACS712 Low Current Sensor

Before I begin, just to let you know that I'm new to electrical engineering, in case that my question sound weird to you, but here's my problem. I bought few days ago ACS712 Low Current Sensor and ...
0
votes
1answer
36 views

Trouble shooting IR Sensor

I am trying to build a heart beat sensor. I implemented the application circuit suggested by the datasheet of the sensor. But I get a constant reading at the Arduino. I confirmed that the IR ...
0
votes
2answers
66 views

Pressure sensor unstable after Arduino power off/on

I am using my Arduino Uno to read analog sensor values from this pressure sensor. I have the Arduino powered with a 12V power supply from the wall. I'm using the 5V from the arduino for the LCD and an ...
1
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0answers
1k views

NTC Thermistor Resistance Calculation for circuit using Wheatstone bridge, Op Amp & Arduino

I'm trying to work out the formula for thermistor resistance when using Wheatstone bridge/op amp circuit as opposed to a voltage divider circuit. I know for a voltage divider the \$R_t\$ value is ...
0
votes
1answer
59 views

periodic spikes in analog sensor

I am using Arduino duemilanove and a Sharp gp2yoa21 sensor for proximity sensing. Now i will be using it to calculate the distance as well so i need pretty consistent and smooth data. But i observe ...
-4
votes
0answers
18 views

nrf24l01 in not working correctly for specific bard but board and module is correct [closed]

i brought a nrf24l01 rf module which is working as transmitter and receiver separately but one of my module is not working as receiver with arduino i have replaced all components except arduino uno ...
0
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0answers
29 views

Ughh… My Arduino Code ain't workin'… And i just couldn't see any problems… Any thoughts? [migrated]

So i'm workin' on a counter just for fun. How it works is when you press BUTTON1 the LED Lights up red, the buzzer beeps and the variable "counter" adds one to itself; After counting, u can press ...
0
votes
3answers
67 views

Electronically, how to control this 5v arduino-style relay board from a PC serial port

I have the following relay board (pictured below), and to activate any of the relays, you simply connect one of the IN1-IN8 pins to ground. Easy. The current going between gnd and INx is negligible, ...
0
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0answers
21 views

Parallax servos (from BOE) move when no commands are sent through Arduino

I have Arduino zero and I'm using two continous parallax servos for movement. I have 2x5AA batteries, 5 for arduino and 5 for servos (1.5V each battery). In code I only use servo.attach(pin) nothing ...
0
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0answers
34 views

WiFi obscuring 433mhz signal reception

I have a WiFi arduino device with a 5dbi omnidirectional antenna and a 433 mhz receiver board, based on Aurel AC-RX with a 17cm stranded copper wire Antenna both enclosed into the same box. This ...
0
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0answers
40 views

Another mad guy trying position tracking with accelerometer (ADXL345)

I know... there've been a lot of discussions about if dead reckoning is possible with accelerometer... and i know the answer is "It is not possible without an external reference resetting the ...
0
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0answers
29 views

Flex sensor or are there better sensors for my application? [closed]

I'm building a project where I need to use a sensor close to the one here: (Flex Sensor). I'm using this sensor in a glove to move servos when my fingers move. Like this My question is are there ...
2
votes
3answers
4k views

Getting ADXL345 accelerometer to work over SPI with Arduino Uno

I'm using this cheap ADXL chip with Arduino Uno. When I read the sensor with I2C - it works fine. However I have some servo motors as well which generate a lot of noise and when I turn the motors on, ...
0
votes
1answer
37 views

Arduino Nano + HC-05 AT not working

I have arduino nano + HC-05 bluetooth module. I have used following pins D9, D10, D11 for HC-05 KEY, TX, RX and this works for data communication without any problems. D9 pin is set to output pin ...
0
votes
1answer
58 views

How do you drive a stepper motor with an L9110 driver module? [closed]

I have a dual channel motor driver module based on two L9110 H-bridges: The documentation and many, many tutorials on the internet mention that this can be used to drive two DC motors, or a signle ...
3
votes
2answers
216 views

US5881 Hall Effect sensor not detecting AC field

Yesterday I was disappointed to learn there is no magical IC to measure current flow in a standard appliance cord. On the advice I received, I went ahead with a US5881 Hall effect sensor and split ...
0
votes
1answer
65 views

How to use arduino nano to switch an 230V AC motor on/off?

I want to switch on and off an 230V AC motor with a relay what is controlled by an arduino nano. The on time and off time would be able to set by a 3-position slider switch. So would be 3 different ...
-2
votes
1answer
63 views

Is there supposed to be a voltage differential between V- and Earth Ground on my Power Supply? [closed]

I'm debugging something in my machine that's causing it to blow my communication chips (AtMEGA16U2 for USB connection) when I noticed a voltage differential of 0.3VDC-0.9VDC between V- and GND on the ...
0
votes
0answers
50 views

how to open a lock using RFID?

I want to use RFID to open a lock with an Arduino and I was searching in the internet about the components that will help me do that. My question is : do I need a servo motor or a relay to open the ...
0
votes
0answers
24 views

Arduino driver not work, cannot verify digital signature see code 52 [migrated]

For the first time once I wanted to connect my Arduino 2560 board to the PC through USB cable then the situation is following: Connection of USB cable between Arduino and PC Driver does not ...
0
votes
0answers
18 views

Trying to print text on LCD display from Arduino trinket [migrated]

I'm trying to simply program an Arduino trinket to display some text on an LCD display. I'm basically trying to follow this, except connect it to a Trinket rather than an Arduino Uno. The background ...