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Questions tagged [arduino]

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

2
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0answers
80 views

Is it okay to connect 2 lithium ion battery in parallel to a charger that can maintenance 4.2V? (more detail in post)

So I'm planning to make a charger that can charge multiple lithium batteries in parallel with hope to use recycled one. I fully understand that they are dangerous when you do it incorrectly, so I just ...
2
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0answers
102 views

BDM (Background Debug Mode) with Arduino

I'm trying to talk to a 68HC(9)12D60 (Motorola/Freescale/NXP) via BDM protocol. This chip is a 112-pin TQFP. On the PCB, there is a 6-pin header (which is not the standard BDM 2*3 pins header). The 6 ...
2
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0answers
28 views

Way of powering Arduino+GSM Modem+Cam off 5V powerbank

I'm trying to build a circuit, that would turn the Arduino on by a PIR sensor, take the picture by ArduCam, then transfer it onto a webserver. I got the SW site covered by now, so that is not a big ...
2
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0answers
216 views

A curious 433 MHz signal to decode

I bought a cheap set of remote controlled power sockets and I want to integrate them into my home automation system. So I got a 433 MHz receiver for 1€, connected it to my Arduino and tried to decode ...
2
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0answers
297 views

Prototyping a smart boxing glove: Where to find a “wearable” force sensor that can detect up to 2000 psi

I am working on prototyping a "smart" boxing glove that can track the movement (jabs, uppercuts etc.) and punch force. I am having a bit of trouble sourcing a pressure (force) sensor that is small ...
2
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0answers
408 views

What's necessary to properly decouple/filter a PWM-controlled fan from an Arduino?

I've got a small problem I could use some help with. I am using an Arduino to control a cooling system I am building for a DSLR. Primary goals are to use PWM and some pots to control TEC power, as ...
2
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0answers
1k views

SPI SDHC Initialization Timing Problems

I Have a 16GB Wi-Fi SD HC Card from Transcend. I try to initialize the card via SPI using an Arduino Uno, sending CMD0, arg: 0 , CRC: 0x95 response:0xFF but the expected response is: ...
2
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0answers
238 views

MCP23017s and arduino problems

I'm not native English speaker, so forgive me my bads. Ok. Here's the deal. In my Arduino UNO I need more outputs and inputs. I bought 3 MCP23017s. One of them for receive states from 8 ...
2
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0answers
353 views

Strange stepper motor behavior- moves too far

I have 3 CD drive stepper motors on a 9V 2A power supply, and they are being driven with EasyDrivers. I am using an Arduino with grbl to control the drivers. The current for the motors is at the ...
1
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0answers
25 views

Arduino Nano - Multiple 5v Power Sources

I am planning on building a small device that sits inline for a SNES controller to allow remapping the buttons. My initial idea is to use an Arduino Nano, but I'm a bit unsure about how best to do it. ...
1
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0answers
55 views

How to rotate a square on a TFT ILI9486 screen with Arduino

Problem Summary I have a “square” rotating on my 3.5 Inch TFT screen (ILI9486 driver) with dots/circles at each of its 4 corners. It is connected to an Arduino MEGA 2560 There are a few issues with ...
1
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0answers
29 views

Interface with wired alarm using Arduino or similar

My house is equipped with a wired alarm system that's missing the hardware controller board. Whats left is a number of sensors (NC) and the wiring to a central location. Cable lengths are anywhere ...
1
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0answers
59 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 ...
1
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0answers
34 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 ...
1
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0answers
30 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 ...
1
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0answers
46 views

Connecting door strike to relay

First of all I know there are many similar questions answered but I'm still a bit unsure on why my current set up doesn't work. I'm really outside my area of expertise so be kind. This is what I have:...
1
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0answers
53 views

Electro magnetic interference with Arduino Uno and a portable radio

I'm surprised when I'm working with Arduino Uno, by just sitting beside a portable radio, like when I was powered on both Arduino & Radio and when they are close to each other I got some noise ...
1
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0answers
41 views

Sharing power between components in a Arduino circut

I am trying to power both an ultrasound sensor (HC-05) and an infrared sensor (FC-51) from Arduino's 5V pin, connected in parallel. The circuit is very primitive. When connected separately, both ...
1
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0answers
56 views

Arduino Nano controlling led strip - cant power leds

I bought a arduino nano (ATmega328P Nano V3) and a led strip (sk6812 3535 4mm), to control the led strip with the arduino. Now i ran into problems with the power supply i guess. The idea came from ...
1
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0answers
22 views

Mosfet Based impulse voltage generator

enter image description here **Details- Mosfet_1 will turn on for 20ms and charge the capacitor C2 and after that, it will turn off. Then the Mosfet_2 will turn on for 3ms with 40kHz frequency and ...
1
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0answers
50 views

Can the idle state of MOSI cause issues?

I have an issue when communicating with an ADC over SPI. If I imitate the SPI protocol via bitbanging then I have no issues with communication; however, if I use the SPI hardware (I've tried Arduino ...
1
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0answers
70 views

(Arduino) When turning TIP120 on again, sometimes the slave flashes trigger without being told to. Why?

I have two mini slave flashes, that have no stand-by modes by themselves. So, even when charged and ready to flash, current keep flowing from the two AAA batteries each, and, if I forget to turn them ...
1
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0answers
71 views

Control variable external power supply with Arduino

I'm currently working on an air pollution controller project and I have a problem to control an external power supply to supply 5V, 1.5V or 0V to an MQ7 gas sensor. Using the direct PWM output to ...
1
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0answers
78 views

Indicator LEDs on Arduino current blocking

So I just inherited a project. I am designing a board for a mega32u4 smd microcontroller that has indicator leds on 8 input and output pins (4 digital (3pwm) and 4 analog) that light up green when a ...
1
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0answers
210 views

Custom Arduino powered board (CH340C) Serial Problem

I made this custom board that contains a complete arduino nano on it. I soldered every component with extreme care and already check all the connections and they all go according to the designed ...
1
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0answers
256 views

Can anyone help me get this running? (ILI9806E TFT on a teensy 3.5)

I am at one of those points where I just can't seem to see the forest for the trees. My previous experience with TFTs has been pretty much 'plug and play' using adafruit's breakout board kit and ...
1
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0answers
72 views

Servo sometimes freezes when used with another servo and MFRC522 RFID reader

I have looked, Googled and researched all over by now and I have not been able to find anyone experiencing a similar issue to mine, so I thought now would be the time to ask my own question on SE. ...
1
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0answers
117 views

Faulty H-Bridge Design L9110s

I am trying to integrate a dual h-bridge design in to my custom PCB (Arduino Nano with integrated motor driver) using the L9110s IC. However, I am struggling to get it working properly. The h-bridge ...
1
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0answers
61 views

Control servo with 4 wires with Blynk

im a beginner in coding and I was wondering if I could control an old servo using the Blynk app. I want to control the direction, so it can unroll the screen up and down. We opened the servo to look ...
1
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0answers
85 views

My BLDC motor is stuttering and I have no idea why

I'm driving 2 BLDC motors with two ESCs, the motors and the ESCs are powered by an external LiPo battery and the Arduino is powered via usb. The motors work with pulses between 1000 and 2000 ...
1
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0answers
146 views

NiMH Smart Charging Circuit with Load-Share for Autonomous Robot

a couple of questions/issues for creating a NiMH smart charging circuit with load-sharing. Background I have a functional autonomous robot based on different MCU including Arduinos and a Raspberry ...
1
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0answers
1k views

PID temperature controller with Arduino using a NTC thermistor and a Peltier Cell

I'm trying to control the temperature of a LED laser (which have a thermistor as temperature sensor and a Peltier Cell, both integrated with the laser) and what I'm implementing is a PID controller ...
1
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0answers
150 views

Audio op amps - what do they do to the audio I hear from the speaker?

I have a simple DC circuit which outputs audio from a ESP8266 attached via 2 wires and a NPN transistor to a simple speaker. It uses this library : https://github.com/earlephilhower/ESP8266Audio/ to ...
1
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0answers
51 views

Photocoupler to Latch Microcontroller Power Supply

I'm revising my custom arduino circuit which involves powering an atmega328p. I am using a 9V battery connected to a BS170 MOSFET. Without any voltage applied to the gate of my BS170, the battery is ...
1
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0answers
88 views

Shift Register with non sensical output

So I have two daisychained 74HC595 Shift Registers driving 16 low current LEDs, and the shift registers are wired to an Arduino Mega. Initially the ciruit worked perfectly, the test code scanned left ...
1
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0answers
356 views

Ultra low power arduino wireless sensor : care of battery discharge

I'm prototyping a ultra low power wireless sensor. To consume less I run a arduino mini pro at 1.8V at 8MHz with sleep 99% of time. The power comes from a LIR2032 coin and the 1.8V is generated from a ...
1
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0answers
395 views

Photodiode OP-AMP circuit for UV light radiation

The project: The aim is to be able to use the photodiode to detect plasma (radiation in the UV light spectrum). The photodiode suggested for this application is the BPX65 and I currently have access ...
1
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0answers
52 views

Measuring sensor noise on analog channels of common single board computers

Using the "MATLAB support package for Arduino" package, I am trying to characterise the analog input channels on an Arduino Uno board. The underlying assumption is that all sensors are inherently ...
1
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0answers
112 views

Using NPN transistors as switches for low-current, 3VDC infrared transmitter device

I'm currently trying to hack up an IR remote for electric holiday candles so that I can use Amazon Alexa or Google Home to turn them on or off. To do so, I need to trigger the switches on the hand-...
1
vote
0answers
98 views

Choice of the right stepper motor

I need to make a precise angular rotator for my directional antenna. The goal is to rotate the antenna at a precise angle. Arduino stepper motor library has functionalities to run a stepper motor for ...
1
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0answers
191 views

High current draw through DC-DC boost circuit

I currently have a simple circuit below which works fine but I am confused with the readings I am getting for when the Atmega1284P is put to sleep. When it is operating I get a current draw of around ...
1
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0answers
2k views

Light Strip with ESP8266 and ZigBee for HUE Bridge

I currently have an ESP8266, which controlls my WS2812b light strip. I want to add it to my current Hue setup(1 Bridge, 4 Lamps). I know that I'll need a ZigBee module of some sort. Are there any I ...
1
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0answers
277 views

30A Relay resets Atmega8A MCU as it engages. Are these PCB layouts to blame?

I am designing a PCB that uses an ATMega8A MCU to switch two high power relays (Songle SLA-12VDC-SL-A). I have used 2 separate approaches with the same disappointed result: the ATmega8A will reset as ...
1
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0answers
850 views

Problem with Arduino Pro Mini and RC522

I have a problem with a circuit and I couldn't figure it out why is this happening. This could be a silly mistake by me cause I'm not really an electronic expert. So after spending some days ...
1
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0answers
282 views

Adafruit Trinket Analog Button Inputs

I am using a Trinket's (not pro) analog inputs to read differing resistances from button presses. When any of the buttons are pressed, I want the internal LED to light up. I have the buttons ...
1
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0answers
39 views

make arduino start when a line is broken

simulate this circuit – Schematic created using CircuitLab Hi. I'm trying to build an anti-theft project. Where if you break a thin wire connexion, It should power ON the arduino and let it do ...
1
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0answers
162 views

Closed-loop systems - discrepancy between Simulink and Arduino

I am trying to figure out how to reproduce closed-loop systems in Arduino that were designed initially designed in Simulink. Take the following closed-loop system with unity feedback and gain: Where ...
1
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0answers
681 views

RFID tag Emulator

I'm having a hard time figuring out how to emulate 13.56Mhz RFID Mifare tags using Arduino and basic components i have tested some ideas but i couldn't read bytes due to difference in protocols and ...
1
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0answers
622 views

Sonar HC-SR04 analog output. Multipoint Sonar Radar

Im working on replicating the work found on Ultrasonic Radar; Multi-Point. It bypasses the echo out on HC-SR04 and enables full analog output to Arduino ADC. The results are quite good but unlike the ...
1
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0answers
184 views

Zero Cross TRIAC circuit for regulator fails on voltage spike

I am using a ZC TRIAC circuit to switch and regulate an electric appliance e.g. a table fan, a electric drill etc. I must confirm that proper SNUBBER circuit is used and everything works fine. I ...