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1answer
9 views

Control inverter using Arduino PWM output

I'd like to control a frequency inverter using an Arduino Uno board and inverter analog input, in order to control AC motor speed. To do this I need to vary inverter analog input voltage. Inverter ...
0
votes
0answers
7 views

Arduino/Netduino: connecting a second power supply's ground to GND pin

I'm planning to play around with an addressable LED strip and a Netduino, and having read some tutorials I've learned that I will need an external power supply to provide enough current to the LEDs. ...
1
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2answers
104 views

High Frequency Logic Level Conversion

I am using Arduino DUE for my project which gives a 3.3 volt output signal. I have to convert it to 5 volts to use it with another device. The problem is that my signal frequency is 1 MHz. I have ...
1
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2answers
142 views

Multiplexing problem with Arduino, MAX7219 e BJT

I tested the circuit below with an Arduino UNO, a MAX7219 and BC338. The sketch in Arduino is a chaser, so the leds should turn on in sequence. It consist of 7 segment (A-G) and two Digit (0-1). The ...
3
votes
1answer
1k views

Arduino - Trigger an iPhone's touch screen with no human interaction

I'm trying to replicate part of this experiment. Specifically, I want to touch the screen with a cable and some aluminum foil whenever I send a signal from an Arduino pin. From the blog post linked ...
3
votes
8answers
894 views

Can I use an op-amp to supply itself a negative voltage?

For my project, I am using an LM324. According to the datasheet, its power supply can either be +/- 16V or 0-32V (max). The output will range from -3V to +3V (or there abouts), so I realise I'm going ...
2
votes
1answer
50 views

Increasing RF24 range using an antenna

First time poster here on electronics, so please excuse any big mistakes. I'm working on a project that uses the NRF24L01+ chip for radio communication between an arduino uno and a raspberry pi. It ...
0
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3answers
71 views

switching with transistor

I want to feed the load by 1.2V source. I want to control it by a voltage changes between 0 to 2 V. I want the switch be closed and feed the load if control voltage is lower than 0.2V and switch be ...
0
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1answer
141 views

Magnetic Levitation

I am new to electronics, and I want to do a project where I make a device that levitates an object with the use of an electromagnet, for learning purposes. Something like this is what I had in mind: ...
0
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1answer
83 views

Insufficient ground supply on my circuit? Ground capacitive foil

I'm playing with a wireless sensor device (with atmega, xbee, and Capacitive sensor (simple foil)) that works fine with the lab power supply but as soon as I try it with AA batteries stops working. ...
0
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1answer
450 views

How to amplify the signal of a TCRT5000 phototransistor

I'm trying to read the IR signal from my Itron C1S Power meter. It has an emitter that lights up for 10 ms every Wh of consumption. This question is based on my prior question: Use a photoresistor ...
0
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1answer
34 views

automating Contactor to control main breaker

i have place where it has isolated electric panel for machines that should run 2 hours Or on certain temperature before the official working hours for employes. so i planned to automate it with time ...
3
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3answers
2k views

Arduino Code - simple if, else statement?

Basically, I have two led lights connected to pin 2 (led 1) and pin 3 (led 2), and I want led 2 to light up every time led 1 lights up, and turn off every time led 1 turns off. My code: ...
1
vote
1answer
50 views

Load capacitance for a microcontroller crystal?

I know there are lots of similar questions on here, but I've read many of them and am still a little confused. I'm a student making a board similar to the Arduino Pro Micro, using a Atmega32U4 ...
0
votes
1answer
97 views

Replace an Analog Pot with a digital one?

I have a Boost converter with a constant current mode that allows me power a high power led (Vf 34, 3A). I'd like to be able to control the current potentiometer on this device with an arduino. To do ...
0
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1answer
80 views

Looking for a way to output 100-144 Analog Channels from Arduino

I've been searching for days and found 2 ways that could work, but not sure about implementation: Using shift registers like in: ...
0
votes
2answers
89 views

Lower 5V output to 2V max

I am using a 5V 40A(max current) output on an Arduino to turn on (5V) or off (0V) as laser driver. The laser driver requires a max voltage of 2V to turn it on and flips at 0.8V. How can I lower the 5V ...
0
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0answers
22 views

Olimex MOD-485-ISO and Arduino Mega2560

I am trying to use the MOD-485 ISO to communicate an Arduino Mega2560 with a PC as shown below: Both jumpers are on (z-b) and (y-a). For more info please see my post on the Olimex Arduino Forum: ...
0
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3answers
64 views

How can I hook this 8x8 rgb led up to an arduino?

I've looked around for examples but I keep finding single color LEDs or in best case a two color LED but I have yet to see how to hook up a true 8x8 RGB LED matrix up to Arduino, is this even ...
6
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2answers
26k views

How to program Arduino Nano / Pro-Mini / Pro-Micro clone that has no usb port?

I was looking for a cheapest possible option to get arduino and wireless comms for a dimmable light and come across this ebay item when searching for Arduino Nano clone. It has no usb port so how can ...
1
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2answers
2k views

avrdude error - stk500_paged_write() protocol error

I am using my Arduino Uno as a programmer to program my ATtiny85. I uploaded the ArduinoISP sketch to my Uno. I double checked my wiring, did some googling, but I still can't figure out why I get this ...
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0answers
27 views

What are Best Software/Hardware Tools for Cymatics Experiments [on hold]

While cymatics seems a curiosity to some, it seems to me that analog harmonics and resonant frequency patterns can affect amazing things in nature. That said, what tool kits are there for cymatical ...
0
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0answers
32 views

Input power needed to Adruino and 500rpm DC motor

I have an Arduino UNO, two DC motors of 5kg torque and 500rpm(l293D motor driver), two ultrasonic sensors, and a bluetooth. I powered the Arduino with USB cable from PC. Then a 12V battery connected ...
3
votes
1answer
239 views

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 ...
3
votes
2answers
102 views

The Transistor Menace - Questions regarding an Arduino rgb LED project

I've been browsing this forum and the internet now for a couple of days and what I thought would be an easy side project turned into a (for me) quite complicated matter. I'm planning to build a mood ...
0
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2answers
195 views

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. ...
0
votes
1answer
70 views

How to keep the signals at the pins on a Arduino upon software restart

I have a Arduino board, connected to a relay. When the digital pin on the board is set to HIGH, the relay closes. If the digital pin is LOW, the relay opens. Now that from time to time, I will have ...
0
votes
1answer
41 views

24v power supply to 24v and a Arduino [duplicate]

I have a Power Supply of 24 volts and 2.5A. I need something like that: http://i.imgur.com/z4oJukD.png I need a power supply of 24V and almost 1500mA and another of around 8 volts and 500mA (to ...
0
votes
1answer
28 views

Arduino controlled boost converter

If I was to build a 12->65V boost converter using Texas's LM5002 regulator IC, would it be possible to tie an Arduino I/O pin directly to the EN pin to enable/disable the output, while keeping the 12V ...
0
votes
0answers
24 views

Implementation of PSK modulation/demodulation

I want to implement a BPSK modulation/demodulation using a microcontroller (Arduino Due). The carrier signal should be at 1-50 MHz and the information rate at 300 KHz. For the sender part I would ...
1
vote
3answers
64 views

Help with simple Arduino/Transistor/Solenoid circuit

I'm trying to use an Arduino+transistor to control a shutter (which I believe is a solenoid) at work. The shutter is normally connected to a power supply by two small wires (positive and negative) and ...
1
vote
1answer
275 views

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 ...
0
votes
1answer
161 views

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 ...
0
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0answers
28 views

External power source steered by arduino through transitors - voltage differences?

I'm trying to steer rows of leds through arduino and I came into some difficulties. My circuit is inspired by instructable: So I have something similar to this grid of resistors and transistors on ...
2
votes
1answer
34 views

H-Bridge Power Supply Erratic Behavior

Description: I have built a copper plating tank to plate circuit boards and am using a technique called Reverse Pulse Current plating to help aide in the copper plating process. What that involves is ...
0
votes
1answer
70 views

Conductive magnet to read resistor value?

I want to know if I can hook-up a resistor to one part of a Magnet Snap (carried by SparkFun), then another magnet snap to analog-pin on Arduino and still be able to read resistance value? Is this ...
1
vote
2answers
90 views

Arduino and resistors

So , hopefully this is my last question on this system it's about the connections: about the transistor, i want to use it like a switch, so i wanted to know how to determine the value of the ...
0
votes
3answers
1k views

Arduino Uno Doesn't show up under Serial Ports, but it does show up in Device Manager

My Arduino Uno doesn't show up under Serial Ports in the Arduino IDE, but it does show up in Device Manager. I have a I2C Sainsmart LCD connected to the Arduino. Do you have any idea why it would do ...
1
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0answers
36 views

How can I make pinMode calls faster? [migrated]

I'm trying to use 3 pins as capacitive pins along side the Mozzi. I had several attempts and so far the closest I had was using code from the ADCTouch library straight into the main code, but with ...
-2
votes
1answer
46 views

Controlling hi&low voltage of a square wave [on hold]

I have an arduino that make a square wave between 0-3[V]. Now I need to control this wave with this requirements: Low voltage -5< Lo<5 [V]. High voltage[MAX] - 24[V] & bigger then Low ...
0
votes
2answers
1k views

Connecting GSM SIM900A module with Ardunio

I have bought an SIM900A Mini V4 GSM module. Here is the module, I want to configure with arduino to send and receive SMS. Do I have to connect TXD of this module--Tx of Arduino & RXD of this ...
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votes
0answers
37 views

Does anyone know US based seller of HX 711 (24 bit ADC)? [closed]

I need the HX 711 (24 bit ADC) board for building a weight scale. I am using a load cell (85 pound maximum, 5 grams divisions). All the seller of the HX 711 are based abroad mostly China. Shipping the ...
0
votes
1answer
83 views

Method to cycle voltage?

In order to use a sensor (MQ-7: https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-7.pdf) i need to cycle between 5V and 1.4V. Any ideas on how to do this? Thank you!
0
votes
2answers
57 views

Voltage regulator capacitor size

I want to use a LF33 voltage regulator to power a nRF24L01 module from a Arduino Pro Mini. I plan to power the Pro Mini with a 9V battery, then use it's 5V internal regulator to power the LF33 which ...
0
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0answers
5 views

how to remove Adafruit Pro Trinket bootloader flashing startup sequence [migrated]

From what I understand, the Pro Trinket has "Optiboot" which allows it to detect which boot loader you are trying to use, one for USB and one for FTDI. When it's in this "bootloader state" the red LED ...
0
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0answers
65 views

Will this circuit work as a AC-DC-AC rectifier-inverter?

I'm pretty sure I'm missing one or more things from this circuit and can't figure out what (new to this)! The end goal is that an alternating current will come in, run through the rectifier, then ...
0
votes
0answers
28 views

arduino brushless motor angular speed

I am using brushless DC motors for my project. I am controlling the motors via arduino through ESCs. I wanted to retrieve the rad/s speed of each motor. I use the arduino's Servo.h library to send ...
0
votes
0answers
15 views

How do I replace a burnt atmega328 with a new atmega328(bootloaded) in arduino? [migrated]

I have an arduino UNO with atmega 328 whose microcontroller got burnt. I bought a new atmega328. I have another working arduino with atmega8. I followed the instructions in ...
0
votes
1answer
41 views

Arduino water solar heater pump control

I am still a beginner, and I wanted to do this project which will be fairly easy if I follow the code and the pic, but there is something I don't understand about the relay connection: Why is there ...
1
vote
1answer
101 views

What signals can be probed with an oscilloscope on an Arduino board?

I got my hands on 35 MHz analog oscilloscope. I'm trying to learn how to use it. Is there something that can be seen with a scope like this on an Ardiuno board? Clock signal maybe? The board I'm ...