Questions tagged [arduino]

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

Filter by
Sorted by
Tagged with
0
votes
2answers
85 views

How to control 12 DC motors simultaneously with Arduino Uno?

I am using Arduino Uno. I need to control 12 dc motors rated voltage 9V and current 150mA. definitely, I will use MOSFETs and back emf diode for each PWM output. I need to know whether I can use a ...
0
votes
1answer
17 views

send data to server using GET method and sim900a

I am trying to send my data to HTTP server using GET method. When i am sending some hardcoded data manually it is getting stored in database successfully. ...
3
votes
3answers
152 views

Arduino oscilloscope voltage divider design

I'm building an oscilloscope with arduino, but I have some questions about how to design the input voltage dividers without ground. The problem is the oscilloscope only needs one input to measure ...
-1
votes
1answer
82 views

arduino resets when switching on relay

Good day everyone I have the Atmega328P-AU on a PCB (Controller IC used in arduino nano). I have made the connections as shown in the arduino website for bootloading and uploading the code. This part ...
0
votes
0answers
34 views

How to debug Arduino using Atmel studio? [migrated]

I have an Arduino Yun board and an Atmel ICE programmer/debugger. There are 6 pins on the Arduino Yun to connect to Atmel ICE for programming only, but I can't find the pins for debugging. Anyway to ...
0
votes
1answer
71 views

Would this MOSFET be suitable for use with an Arduino?

I'm looking for a MOSFET which can be controlled by an Arduino at 5V, and which can switch power on/off to a Raspberry Pi and peripherals (also 5V) that will peak around 3A of current. It's a battery-...
1
vote
0answers
51 views

Serial.println using Registers in ATMEGA328P

I have worked with ATMEGA328P using Arduino libraries, but new to actual register level coding. To start with that, I have written code for basic Serial.print in ...
0
votes
0answers
38 views

How to ontrol a 12v dc water valve with battery powered Arduino?

I just want to open/close a valve when the soil moisture sensor reports a pre-determined moisture level, using an Arduino. The main issue I'm facing is that most valves operate at 12/24 VDC and I'm ...
0
votes
1answer
45 views

Switch that change its state with a signal of some seconds

I'm making an IoT project for a friend, but I need some tips: I want to use an old mouse sensor and convert it to a movement sensor (just for a door) and if it's activated, a second device (an esp8266)...
0
votes
1answer
78 views

Switching 400V motor with 5V

I'am trying to make an automatic irrigation system using an Arduino, a moisture meter and a water pump. The issue is that I can't figure out whether there is some relay/contactor type component that ...
0
votes
1answer
53 views

Interface NodeMCU with RCWL-0516 Microwave Radar Sensor and power via battery [closed]

I am trying to interface NodeMCU with RCWL-0516 Microwave Radar Sensor and power it via battery. Below is the circuit diagram Below is the Arduino Code I am using : ...
0
votes
1answer
54 views

Writing extra data causing Arduino Mega 2560 to miss sensor data

I am working on a project that requires data from 3 different sensors and syncing is necessary. The first sensor(HX711) is relatively slow proving 80 samples per second. The second sensor(MAX30101) ...
0
votes
2answers
68 views

Controlling DC fan with Mosfet PWM

I am trying to control a 12V DC fan with PWM using an IRFZ44N MOSFET. However somehow the fan is not turning on and off when the gate is pulled to either 0V or 5V (on the power supply). And it is ...
3
votes
1answer
142 views

Arduino- Duty Cycle Changing When Frequency Is Increasing

I’m currently trying to increase the frequency from a pin from an Arduino using PWM. I’m using the Timer1 library as it has functions to output signals. I connected a push button to my Arduino and ...
0
votes
1answer
42 views

ESP8266 ESP-01 internal pull-up at pin GPIO0? +GPIO2 doubt

I have a PCB prototype which uses an ESP8266 module, ESP-01, the first ESP model with a 4x2 male pin header, and I will interface the ESP with a microcontroller. My main doubt is about GPIO0 pin of ...
0
votes
1answer
109 views

Allegro ACS71020 problem interpreting I2C data

I've added an Allegro ACS71020 to my Arduino project to measure power usage (circuit shown below). I can connect to I2C on 0x63 and I get response (check the image below) - but the values do not ...
0
votes
1answer
102 views

uC IO pin driven “low”, but voltage sits at 0.3V, not 0V

This is an Arduino MKR WiFi 1010 board, which runs at 3.3V. PA18_OTG is an IO pin, which by default is driven HIGH (3.3V). In this state I measure the OTG pin at 0V. I need to drive OTG high, so my ...
3
votes
1answer
176 views

Why I need capacitors on VCC? [duplicate]

I want to build my own dev board (mostly to understand some concepts), and I started from some schematics that I found on the internet, but I have some questions about this schematic: Why do I need ...
0
votes
1answer
44 views

Generate unique IP/Mac from samd21 serial

We created 100 custom PCB around the samd21. And I'd like to generate some unique IP/Mac addresses from the Serial number of the samd21. In the datasheet they say the following Each device has a ...
6
votes
2answers
190 views

K-Type Thermocouple, Instrumentation Op-Amp and Arduino

I am Trying to read in a K-Type Thermocouple to a 0-5V Arduino Uno. I Can read my Thermocouple directly using a Fluke meter on temperature setting giving me the correct value of 21°C, but when I ...
0
votes
1answer
76 views

Getting earphone out from music player

I've made an arduino based audio spectrum analyzer & it requires audio input from a music player/laptop/phone earphone out. I've tested this with earphone out from my audio player (Yamaha MCR-...
0
votes
1answer
85 views

Arduino nano + microSD module + ethernet module does not assign IP address

I would like to create a small web server to enable or disable devices via ethernet connection, except that the network module and the SD reader did not seem to work if connected simultaneously. That ...
0
votes
2answers
79 views

Arduino - Not outputting 2 separate signals

I’m trying to get an Arduino to output 2 signals with different frequencies for a project.The schematic of the circuit is shown below. I’m trying to experiment using Pulse Width Modulation to give me ...
0
votes
1answer
56 views

Reading voltage (0-5V) using the Arduino Uno analog input and overvoltage protection for this pin

I need to measure the voltage on the 0-5V power line using the Arduino UNO analog input. As I understand it, this can be done simply by connecting the "+" power line to an analog pin, without using ...
0
votes
1answer
41 views

Arduino / Love-O-Meter : wrong temperature read when LEDs are on

I tried the Love-O-Meter example given in the Startup kit of Arduino. The example is available here. The temperature sensor is the TMP36 given with the kit. If the three LEDs are off (e.g. when ...
1
vote
3answers
75 views

uC controlled MOSFET based LED Dimmer stops responding

I've designed and implemented LED Dimmer driven by PWM from Adruino Pro Micro (CLONE) with software based on MySensors library. See the schematic attached below. The idea is really simple: uC is ...
0
votes
1answer
62 views

Can I use Arduino nano's power straight for the micro motors or do I need to use drivers for a drone? [closed]

I haven't tried using nano as the primary source for the micro motors as I'm still planning for project. If possible please suggest me any motor driver with less weight or if using any MOSFET would be ...
-2
votes
5answers
122 views

Bitwise operations in embedded C if button pressed on AVR circuit

I am using ATmega32 AVR microcontroller. I am confused about bitwise operation in embedded C. I understand (AND, OR, XOR, NOT) logic gates very well, but there is something that I don't understand: I ...
1
vote
2answers
71 views

RPI-arduino communication without UART

I'm working on a project where a raspberry pi zero will be the main controller. The pi has to receive information from a GPS module (gy-gps6mv2) over UART. The same pi will be controlling (receive and ...
0
votes
1answer
70 views

Arduino Mega Schematic possible “Faults”? [closed]

I'm trying to build an standalone Arduino mega based on This schematic. At the header of schematic Arduino noted this: Reference designs ARE PROVIDED "AS IS" AND "WITH ALL FAULTS". As a hobbyist ...
0
votes
2answers
42 views

Can we connect a DAQ to a micro-controller via a CAN bus?

I want to establish communication between an Arduino to a DAQ that I am using from DEWESOFT called the Dewe 43-A. The DAQ has 2 CAN bus ports according to its specs, and I was wondering if I can ...
4
votes
1answer
122 views

Mimic a pick-up coil to drive a CDI ignition

I'm researching why an ignition coil passes ohm's testing but doesn't work. Installed on the vehicle and the engine doesn't run correctly. At first stages of bench testing and I'm still not finding ...
4
votes
1answer
81 views

(Electret Microphone) Why is input taken from the capacitor?

Why is the input signal taken from the -ve side of the capacitor? I do understand that the resistor has been added for voltage divider. Is this actually for filtering purposes? Or is the capacitor ...
1
vote
2answers
89 views

Driving high currents with parallel mosfets as the switch

I am trying to make my own battery spot welder from a car battery, car starter solenoid, and an Arduino to drive them. I came up with my concept and schematic and built the thing. The problem is that ...
0
votes
0answers
48 views

Can't wake SIM800L from sleep mode

I am having some trouble with my SIM800L module. Basically I set the DTR pin to high and then used AT+CSCLK=1\n to put the module into sleep mode. Then, to wake it ...
1
vote
1answer
92 views

Arduino not outputting square wave with 50% duty cycle

I’m currently using an Arduino and my main goal is to output 2 signals from 2 digital pins. Pin 1 (D7) would output a 1 kHz signal with a 50% duty cycle and pin 2 (D8) would output half of pin 1's ...
1
vote
1answer
46 views

Using multiple TCA9548A multiplexers

The case is that I have 5 temperature sensors. I want to connect 4 of them to the first TCA9548A (TCAADDR0), the SDA and SCL busses (from the ports 0 to 3) and connect the fifth one to the second ...
5
votes
1answer
83 views

Modifying El Wire driver for Brightness control

I have an El-Driver that has a potentiometer to control the brightness. I would like to control the brightness with an Arduino, replacing the potentiometer. Here is the schematic of the brightness ...
0
votes
1answer
142 views

Mosfet current control with PWM

I am using a mosfet and an Arduino and I want to control the Source-Drain current of the mosfet by adjusting PWM to the Gate. If I apply zero value to the PWM, the current doesn't stop (I checked the ...
5
votes
1answer
73 views

RS-485 network with multiple masters

I'm building a project with multiple RS-485 senders ("masters") and one receiver: simulate this circuit – Schematic created using CircuitLab I'm using one MAX485 as receiver connected to a ...
0
votes
1answer
44 views

Controlling 12V 70A Motor(s) with Arduino MEGA (or NANO) and a 4-terminal automotive relay

Components I have: Relay (rated at 12V, 70A, cannot find how much current is needed to saturate its coils) Schematic Arduino MEGA and NANO 12V Powerwheels battery + AA battery packs Motor: 00968-...
0
votes
1answer
32 views

Flexible GPIO routing Arduino shield

I want to make a combined MIDI In/Out/Thru + MDX Output shield, so I can order/design just one shield for all my needs. It is intended to use the shield for Arduino Mega which has 4 UARTs, and I want ...
1
vote
1answer
54 views

RC Snubber For Phase Angle Controller

I have a phase regulator and I'm using it for regulating the RPM of a fan - centrifugal blower. The motor is a shaded pole induction motor (220VAC, 28W). The regulator is working fine, but if the RC ...
1
vote
1answer
65 views

Optocoupler - Make active low output at active high

I'm currently working on a project and it consists of amplifying a 5V signal from an Arduino to 24V. I made my circuit and hooked it up to a oscilloscope and it shows that the output of the ...
-3
votes
1answer
64 views

ATMEGA328p powersupply 3.8volt and Sensor 5V input power

I have a little doubt. If I use a microcontroller powered by 3.7volt from a lithium battery and I want to connect a sensor that needs 5 volts of power(external). Can works the ADC of microcontroller ...
0
votes
1answer
55 views

Programming ESP8266 in circuit

I've designed a simple WS2812B LED Controller utilizing the ATMega328p and an ESP8266 to connect to WiFi. The two are supposed to be communicating over UART. I've made a mistake of not testing the ...
0
votes
1answer
63 views

Why cannot I use the USB port directly to communicate via PC with STM32F4-DISC

I will keep it short and clean, if it won't be enough please let me know and add more details. When using an Arduino UNO, a serial communication can be achieved by the same USB connection which is ...
3
votes
1answer
115 views

Using op-amps to read real-time resistance values over a wide range

Background I have been using a simple inverting op-amp circuit and Arduino to measure the resistance of a photoresistor (light 5k, dark 200M), like in the schematic below. This provides linear data ...
0
votes
1answer
74 views

Arduino (STM32) and MOSFET switch with digital pin

What circuit can I use to switch on a speaker with an arduino (stm32 board)? Ideally the speaker will run longer (automatic off after some time-0.5s) I have a stopwatch program in STM32 (...
0
votes
1answer
84 views

LDO voltage regulator, no output

I'm making my own board based on Arduino. To power it I use one LIR2032 cell (button cell 3.6V li-ion battery) that's driven through 3.3V LDO voltage regulator. So far I have tried two different ...