Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [arduino]

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

0
votes
3answers
73 views

Drive P channel MOSFET with Arduino, unable to get desired behaviour (LOW pin, MOSFET ON)

After hours of building a circuit on a perfboard, I discovered that Vgs is not easy with P-MOSFETs. After searching I figured out that I need to use either a N-MOSFET or a BJT (NPN) to bring the ...
1
vote
1answer
35 views

YM2612 Circuit Audio Signal Noise

I'm working on a project where I'm controlling a Yamaha YM2612 with an Arduino MEGA. I can communicate with the chip just fine, but I'm having problems with the audio signal the chip is outputting. I'...
2
votes
1answer
24 views

Can Mq4 sensor be used for smoke detection?

I wanted to ask if Mq4 can be used for fire smoke detection? I read it have small sensitivity to smoke in the data sheet, but I wanted to know what is the least value in ppm for it to detect smoke ? ...
3
votes
1answer
56 views

Why is serial output from shift register offset from others?

I was debugging my circuit that uses TI SN74HC595 shift registers, which I daisy chained. I transfer data to she first shift register using an Arduino, and SPI library as it is faster than bit-banging....
0
votes
0answers
39 views

Charging lead acid battery using LM317 and PB137 in series

simulate this circuit – Schematic created using CircuitLab I am making an Uninterruptible power supply (UPS), to power some data logging equipment (requires a supply V of 10-30V DC). I have an ...
-1
votes
1answer
40 views

Base resistor for BJT Transistor [duplicate]

I'd like to use PBSS4350SS transistors for driving multiple low power solenoids, but looking at the datasheet I can't figure out what value the base resistor (R1) should be? simulate this circuit &...
0
votes
2answers
80 views

Atmega 8 on Arduino Uno

For a uni project I am tasked with programming embedded C onto an ATMEGA 8 uC, and there aren't enough development boards for everyone to use at uni, so I have an ingenious solution. I have several ...
0
votes
1answer
60 views

Mq4 sensor doesnt detect natural gas but detects cigarette lighter gas only! [closed]

I am working on a project for detecting natural gas of cooking stoves, I have tested several sensors but the mq4 sensor was the one that worked fine. Now after about one month of using the sensor i ...
0
votes
0answers
16 views

SIM800C MQTT vs TCP Power Management

I have implemented the code similar to this tutorial https://www.youtube.com/watch?v=5FbafyVvN3E but have used different cloud address and port and have used sim800c module in a custom board with ...
1
vote
1answer
55 views

ESP8266 module emits random/garbage characters on external supply (but works on arduino's 5v & 3.3v)

Summary: With arduino's 5v & 3.3v supply , ESP8266 module emits boot messages and responds to AT commands on serial terminal@115200 baud as - boot message: ...
2
votes
2answers
62 views

Running 20 WS2812 LED strips (80 pixels each) from a single Arduino and 24V Power Supply with Buck Converters

I am building a matrix with 20 WS2812 LED Strips. Each strip is 80 pixels for a total of 1600 pixels. I want to drive them all from a single Arduino Mega board. To handle the power needs, I have a 24V ...
0
votes
1answer
117 views

How to make communication between microcontrollers

I want to make a project where it is necessary to communicate between several microcontrollers in the fastest way possible. For that matter I have 10 micro-controllers whose names will be 1 ... 10: ...
1
vote
0answers
82 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 ...
0
votes
0answers
36 views

Does a pin (input pin arduino) still float when connected to GPIO on RPI? [migrated]

I am currently testing my application on an arduino, and I experience floating pin issues. My program reads the pin status of input pins, which are configured as ...
1
vote
1answer
83 views

how can I motorize hand cranked standing desk

I already have a hand cranked sit stand desk, which I would like to motorize without too much damage to the existing mechanism and (for not too much money). As it is hand cranked, there is an existing ...
0
votes
0answers
32 views

H Bridge Outputs correct voltage, but the Motor doesn't function when connected. The Motor does work when power is supplied directly

I am building a bluetooth controlled car with an arduino Uno, and I am powering the motors with a 6V battery. The H Bridge I am using to control the motors is an ST L293E, and I am following this ...
0
votes
0answers
35 views

cost efficient BOM for total 10x12 16 segment (1920 led) display

I've already built a few test prototype for a large(ish) 16-segment display board. I want to use a Arduino of ESP8266 to run it, with external power, and ICs for the Characters. So far, I've been ...
2
votes
0answers
18 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 ...
-6
votes
1answer
53 views

mosfet circuit without get supply mosfet on, why? [closed]

in ckt i not give gate supply and vd=12v than vs=12v in this condition mosfet not work as switch. why this?
1
vote
3answers
166 views

Why are my relays dying?

I am using a SainSmart 5V 2-Channel Relay Module for Arduino to drive a hot plate (110V, 1000W). I plugged my Arduino VCC and GND to the VCC and GND pins of the relay board and I drive both relays ...
0
votes
1answer
145 views

How to flicker high-power LEDs with precise square or sine wave?

I need some advice regarding a setup with high-power LEDs I am currently working on. My aim: I have a set of 6 high power LEDs (http://www.roithner-laser.com/datasheets/led_highsingle/apg2c3-530.pdf) ...
0
votes
2answers
59 views

Is a relay stressed by a partial activation of the trigger?

I'm using a relay like the one in the picture, controlled by an Arduino. I basically use it for turning mechanically on/off a circuit, when i have 0 as constant output from a series of values that ...
0
votes
1answer
74 views

Controlling an Array of Motors

I am trying to measure the state of a switch on a vending machine motor (model # BC-D27/28). It has a micro switch on it that has a lead going from COM1 to NC2 when engaged and COM1 to NO3 when ...
0
votes
1answer
54 views

Is there some way to measure mains voltage with the ACS712 sensor?

Last year I went to a maker event where some guys used an ACS712 sensor with an Arduino to monitor the mains voltage and current to monitor the energy cost in the house. One thing I saw there is that ...
1
vote
1answer
51 views

Control 24VAC solenoid with arduino using a octocopuler and a Triac

Following a previous question I implemented the following schematic on my PCB. The schematic : My PCB: I have been unable to make it work, if I measure the voltage on j13 it's allways 25v, i know ...
0
votes
1answer
29 views

Charging SLA Battery

I currently have a project requiring the use of a battery. My project has to be able to run off the battery power, but when an outside source is connected, the battery should be able to charge off ...
2
votes
1answer
58 views

I2C & SPI - share clock lines?

I know mixing SPI and I2C is a bad idea, but, when using a microcontroller short on pins, is it safe to share clocks between both buses, provided both are running at bus-tolerable frequencies? In my ...
1
vote
1answer
26 views

Arduino Fails to Program Custom NRF52, But Has Worked In Past

Background: I have a custom board that consists of two PCBs connected via a 100mm Picoblade connector. The "Aux" board has a USB port, and CP2102N Serial=>USB converter. The "Main" board has an NRF52 ...
3
votes
1answer
127 views

How To Reassign The MISO Pin?

So I have a PCB with an LCD hooked up along with a 595 shift register. Unfortunately, when I designed the board I didn't realize that the LCD library used SPI, which on the Arduino Uno is pins 13-10. ...
0
votes
1answer
42 views

Simulate Automotive Speedometer Sender

I am working on a project and I have run into a little bit of a problem. I have a speedometer gauge that I am trying to send a signal to on a bench (out of car). The way in wich the it works is ...
0
votes
1answer
27 views

Mega2560 master on RS485 bus stops communicating with VFD when I add another RS485 module

I’m doing a project where I’m building a control panel for a VFD (inverter/variable frequency drive). I’m connecting the two over half duplex RS485 and use Modbus RTU. As a master I use a Arduino Mega ...
0
votes
0answers
60 views

Run Stepper motor with more torque and smoothly

I have a stepper motor and its torque curve is below. I am trying to get more torque from the motor. Therefore, I decided to setup my driver to half step. I am using an Arduino for generate the ...
0
votes
1answer
70 views

Which kind of motor is best recommended for a curtain opener?

The general idea is to build a curtain opener, using some kind of motor connected to my arduino. Which will cause the pulling-functionality... So the following options are : 1. DC motor I feel like ...
0
votes
1answer
69 views

How to detect mains outage for 12V SLA battery charger

I'm wanting to use a 12V SLA battery and off the shelf mains charger as an uninterruptible power supply for an Arduino or similar device (via an appropriate 12->5V regulator) as also described here ...
0
votes
1answer
39 views

Using potentiometer in two separate circuits [closed]

I am building a circuit with Arduino to control the motion of a stepper motor. I want to use my guitar amp potentiometers to feed voltages back into the Arduino without disassembling the original ...
0
votes
2answers
80 views

Implement 7 DPDT-switches with Arduino [closed]

OK, so my problem is the following: I have a commercial box with mechanical DPDT-switches for controlling valves by changing the polarity of 2 wires per valve. The box has 7 relevant switches, which I ...
0
votes
2answers
111 views

Emulating an SD-Card with a microcontroller (or Raspberry Pi)

some background to my story to begin with: I went to a store and asked for a bluetooth fm transmitter for my car and the guy sold me something that only plays from an SD card and I didn't even bother ...
0
votes
2answers
64 views

Arduino Nano disconnecting from PC on plugging in 3.3v NRF24L01 into PCB

I've built this PCB which includes two I2C port expanders, an Arduino nano, inputs for buttons and encoders, and headers to plug in an NRF24L01 board. Currently, I just have code running to read two ...
0
votes
1answer
37 views

Can I control/read an RFID reader with an Android device or do I have to put an Arduino board between the two? [closed]

I want to develop and Android app the reads RFID tags. I am wondering if I can control the RFID reader directly with an Android device or do I have to put an Arduino board between the two. The RFID ...
0
votes
1answer
54 views

MCP23017 with NODEMCU v3 (lolin) i2c doesn't work

I want to use NodeMCU v3 with MCP23017 that has MAX6675 at the end. Everything is on circuit please see the image. MAX6675 (U3) doesn't want to work with MCP23017. First MAX6675 (U4) works perfectly ...
0
votes
1answer
52 views

Ultrasonic cleaner control with Arduino

I'm trying to build a small sized ultrasonic cleaner. I bought a couple ultrasonic transducers (ranging between 40kHz - 102kHZ and 15 - 35 watt) which I want to play around with. There are already ...
0
votes
1answer
14 views

connecting 1-Wire device powers off wemo d1 mini

I have a wemos D1 Mini (an ESP8266 chip) which I am trying to connect to a 1-Wire temperature sensor. However when I plug it in the 5v or ground it seems to power off the device, this happens with or ...
0
votes
0answers
16 views

How to use many separated A4899 for controling steppers

Basically, I was seeing the diagram for the A4899, in which mentions a logic power supply(image for reference), the thing is, how would it work if I needed more than two drivers? I was worried that ...
0
votes
2answers
113 views

High-Power Switching using MOSFETs

For a project, I need a means of switching a high-current circuit between two inductors. The purpose is, each inductor serves as an electromagnet, and they are switched every 15s or so in order for ...
0
votes
1answer
43 views

Operating a 12V electric lock with arduino

I have a similar electric lock-style solenoid like this one. If we trust the manufacturer it draws between 1.2A and 2A at 12V .I'm currently using a N-Channel MOSFET 60V 30A - FQP30N06L it works just ...
1
vote
0answers
140 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 ...
0
votes
2answers
81 views

Help figuring out the interface on this bill validator?

I would like to interface this bill validator to a microcontroller (Arduino Mega). The website says it supports RS232,RS485,Optoisolated RS232 and USB interface. The one I have is currently intefaced ...
0
votes
2answers
43 views

Regulate 12v flow with a mosfet

I have an electric lock that needs 12v to stay in a lock position. It opens on 0v. I was thinking about controlling this with a MOSFET (IRFZ44N). Currently I have the following setup: The 12v power ...
0
votes
1answer
71 views

AVR programming

This question might be asked somewhere, if so all references would be appreciated. Hello, I have programmed Atmel chip Atmega32U4 through USB. It is possible because it supports USB programming. I ...
0
votes
1answer
24 views

How to configure my xbee s2c modules for communicating with arduinos + sensors?

I have two xbee module (fixed on a development board), these boards does not have a individual access pins to access xbee pins (photo included), but rather a RS232 port. As for what I have searched, ...