Newest Questions
25,002 questions
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ItsyBitsy 32u4 missing keyboard.h [closed]
the ItsyBitsy 32u4 has the HID and can emulate a mouse, but when I do the #include "Keyboard.h" it says file not found in the board definition in the IDE.
Is there something missing in the ...
0
votes
1
answer
45
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Using Serial Port names as a variable array for looping access to same block of code
If I have multiple NODES one on each Serial port (and / or SoftwareSerial port) all of which have the same code for execution can the names of each Serial port be put into an array such that I can say:...
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0
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62
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Arduino Not Activating Solenoid with Active-LOW Relay
I'm trying to control a 12V normally closed solenoid valve using an Arduino Uno and a 2-channel 12V relay module. My goal is to have the solenoid turn ON and OFF every 10 seconds.
I've tested the ...
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0
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25
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BPW21R photodiode with OPA2134UA op-amp circuit reading constant 5V instead of expected signal [closed]
I have built a circuit using a Nano, a BPW21R1 photodiode, and an OPA2134UA dual op-amp IC to amplify the signal, but I'm getting a constant 5V reading instead of the expected varying signal, ...
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24
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How to adapt this ESP32 + TMC2240 stepper controller design to my project?
I’m trying to build a wireless stepper motor controller using an ESP32 with a TMC2240 driver. I came across this reference design: Wireless Stepper Motor Controller with ESP32 and TMC2240 https://www....
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0
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24
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How to get HC05 module into pairing mode? [closed]
I have set my HC05 (connected to my Nano) to "master" using AT commands. But I cannot get the light to blink rapidly anymore, it remains blinking slowly as if it is still in AT mode. I have ...
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36
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Why does my stepper motor have jerky motion with DRV8825 microstepping?
I’m using a NEMA 17 stepper motor (model 42SHDC3030Z-23WB-1 / 17HS4401S) with a DRV8825 driver with small radiator and an ESP32. Even when set to 1/16 microstepping, the motor motion is very jerky.
It ...
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1
answer
58
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HC-12 receives garbage, but the garbage is consistent
I'm playing with two HC-12 wireless communication modules. After setting AT+FU4, I tested the modules, but the communication appeared to be unreliable in one direction. I tried to simplify the code as ...
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0
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37
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Information about PWM frequency
Previously, the reference page for the analogWrite function showed the PWM frequencies for different pins on different Arduino boards, but now it doesn't mention it anywhere... Where is this ...
- 101
1
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1
answer
38
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Send uint32_t over i2c from attiny85 slave to atmega328p master
I run into an issue with querying a uint32_t with an atmega328p master from an attiny85 master.
I have put both codes below.
I did run the equivalent code for just sending a uint8_t and all works ...
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78
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enum class not in scope but auto works
I'm writing a program to display leds that sequentially light up in one direction until the last led at which point the process reverses. I'm using an OOP approch for practice. Below is my code in its ...
-1
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1
answer
88
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Connecting the device to Arduino via the UART protocol [closed]
The essence of the task
I have a task to connect an external device with my arduino and transfer data to each other via the UART protocol. The external device has 4 pins (Two for power supply and RS-...
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2
answers
101
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problem with scripts in Arduino Lab for MicroPython
I am trying to set up an Arduino Nano ESP32 so that I can code in MicroPython. I successfully installed Arduino Lab for MicroPython and flashed the firmware onto the device, but when I try to run the ...
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71
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Cannot get Arduino Nano with CH340 chip to keep working
I have a bunch of Arduino Nano boards with the CH340 chip. When I want to upload code to a board, it sometimes works the first time, sometimes it doesn't. Afterwards, it mostly doesn't work anymore.
...
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66
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ASync Timer2 based OSCCAL value
How to calibrate the internal RC oscillator off of a 32768 Hz crystal serving Timer2?
void OSCCAL_calibrate(void) //This version specific to ATmegaXX8 (tested with ATmega328)
{
unsigned char ...
- 136
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43
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Cannot ping a host unless I use parseIP from Ethercard
I'm trying to write an Arduino sketch which pings multiple hosts and switches some RGB LEDs to indicate the status of the devices on my network. This question is a followup of ParseIP in the EtherCard ...
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41
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After an USB disconnect the program I've uploaded to the Arduino Mega 2560 doesn't work properly anymore, why?
For a race simulator I'm using several Arduino Mega 2560 boards on which the code that will post below will be running. (not my code! But freely available on the internet)
Everything works fine, just ...
-1
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0
answers
22
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Why are there silver strips around the voltage regulator on an Ethernet 2 shield? [migrated]
The following image is a crop of an Ethernet 2 shield. It shows the 1117 voltage regulator soldered to 'something'.
Typically these are soldered to a copper pad, with /without vias to other copper ...
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1
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0
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51
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Why LoRa Ai Thinker 433Mhz doesn't go in Receive mode after we send ACK? [closed]
So basically I created a simple Receiver and Transmitter using Two Lora Ai Thinker 433Mhz (Sx1278). I am using Esp8266 with one Lora (as transmitter). It sends packet when we press button. On Receiver ...
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1
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94
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Arduino DUE - I Have enabled A14, will this break anything?
I developed a quick custom PCB using the ATSAM3X8EA-AU as I wanted to use Arduino to program it as an Arduino DUE, I kept most of the schematic the same, however I used pin A14 pin 52 as an analog ...
- 117
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1
answer
70
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How to timeout hung incoming connections to the Ethernet port?
If I telnet to an Ethernet capable Arduino (e.g. shield, Leonardo, Leonardo Eth) with something like telnet [ip] [port] and then do nothing, the connection hangs. Seemingly for ever, or at least ...
- 127
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32
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Reassigning GPIOs 6-11 on a 30 pin ESP Wroom 32
I am trying to wire up the ESP 32 based Crunch-E keychain synth (gituhub repo with wiring diagram here).
In my case I am using a 30 pin ESP Wroom 32 board with pinout diagram here.
The Crunch-E wiring ...
- 101
-2
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2
answers
106
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Trying to program atmega328p-an via arduino leonardo isp
a friend of mine gave me broken hw-308 (chinese meter).
https://besomi.com/media/catalog/product/t/m/tmet0006-1.jpg
Atmega chip was broken so i replaced it with the new one i bought recently. Now i ...
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3
votes
2
answers
160
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Why are there extra steps on DAC output?
Testing the DAC on the Feather M4 Express (SAMD51 microcontroller). Tried to generate a square wave with the DAC.
void setup() {
analogWriteResolution(12);
}
void loop() {
analogWrite(A0, 0);
...
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2
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0
answers
36
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Unnecessary recompille after connection error
I sometimes multitask during a large compile (wifi, etc libraries) and don't get back in time to press the ESP32 upload button. If the connection times out, the IDE recompiles all the source again. ...
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0
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57
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Arduino R4 Minima, trigger function being bypassed?
I am running a trigger function in a while loop in setup that takes in 3 analog inputs, checks if they are within a certain range, then outputs true if they are, false if none of them are.
The code I ...
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0
answers
68
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Gross timing error between crystals
Got two boards, getting a stable counter error ratio between the two of ~0.9895 (counted ticks divided by calculated ticks). Is this not a bit too low ? With +/- 50 ppm between the two crystals I was ...
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1
answer
99
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Difference between using GND and digital LOW for 7-segment display pin
I am using this 4-digit 7-segment display.
So my circuit is basically 220 ohm resistors for all the segments (display pins 6 through 16 on the bottom each go through a resistor before going to a ...
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1
vote
1
answer
225
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Can one re-program a Leonardo Eth via its Ethernet port only?
Let's assume we have an Arduino Leonardo Eth running some sort of networking application, perhaps a very simple web server. Importantly the server is read only and static HTML. There is no ability to ...
- 127
0
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2
answers
134
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I need more free memory on my Arduino. What can I do if I don't want to use float? [closed]
I realize that using float results in loading all or at least parts of the floating point library, which consumes a significant amount of memory.
How can I avoid using float?
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2
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89
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5V DC pump connected to relay on nodemcu esp8266 running non stop
I using a nodemcu v2 esp8266 for my automatic watering system. I used 3v - 5v DC pump for the watering system. The pump is controlled based on the soil moisture level ( or Blynk ). When the code was ...
-1
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2
answers
84
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ATtiny402-SSNR minimum hardware requirement
I am using an ATtiny402-SSNR in a project. I have never used AVR MCUs before, so I need a minimum hardware requirement schematic for this chip. I could not find a schematic for this on the internet.
...
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1
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129
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RTC DS1307 gives random and incorrect time value [closed]
The RTC module can output the hours as 165, and the minutes as 165. This is some random number that is different every time. Everything works fine, but at random times I get this. Maybe once every ...
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1
vote
1
answer
90
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ParseIP in the EtherCard library does not parse an address twice
I'm trying to modify the pings example from the EtherCard library so I can ping multiple hosts. The end result should be a small device which monitors other devices on my network.
Here is the modified ...
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1
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76
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How do I change what variable I am changing based on a separate number?
I am trying to change thing2 if I input 0, and thing3 if I input 1. I don't want to just have if/else to determine if I should be changing thing2 or thing3 because I want this to be more dynamic than ...
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1
vote
1
answer
96
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Reading JSON from Arduino via Serial Missing Parts of Message
I have a project (Digital Dashboard for a Motorhome) in Pi that reads JSON data from an Arduino board and sends it via Serial.
The Pi gets the JSON data, makes some adjustments and then sends it to an ...
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votes
1
answer
52
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Replace bootloader in ATTiny88
There are other threads about replacing the bootloader on Arduino boards, but the ATTiny88 seems to be rather a different beast. Instead of creating a serial port and sending the compiled code to the ...
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1
answer
64
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How to faithfully collect geophone data by modbus RTU?
I am trying to collect data from a geophone using a UNO R4 minima as slave with a Zihatec shield, so that I can integrate it into a larger project on a modbus RTU bus.
The signal from the geophone is ...
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3
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2
answers
1k
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I need compact code to fit in memory
I feel a little like I am back in 1975 trying to fit my code in 4K of RAM.
I am writing some code for an ATTiny88, and the code is starting to get big, relatively speaking. I need to save every byte ...
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1
answer
84
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Arduino HardwareSerial flow control with handshake XON/XOFF
I am sending large texts from PC to Arduino over Serial and I cannot simply copy-paste it, as Arduino is not fast enough to process it on the fly.
I need some flow control (probabely XON/XOFF) so ...
- 1,466
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0
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90
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ESP32-S3 continuous reboot after flashing larger firmware
I’m facing a persistent reboot issue on one of my ESP32-S3 boards after flashing a larger firmware binary. Here’s a breakdown of the problem:
🔧 What’s Happening
After flashing my project (which ...
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1
vote
1
answer
72
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How can I improve ELM327 response stability on Arduino after setup verified with OBD-II scanner guide?
I'm using an Arduino Mega with a Bluetooth ELM327 adapter to read live data from my car’s OBD-II port — specifically RPM (PID 010C). The goal is to log data to an SD card or display it in real time.
...
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1
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1
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77
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How does `delay()` differ from using `millis()` in terms of processor efficiency and responsiveness?
In many Arduino sketches, especially beginner ones, delay() is commonly used to pause between actions. However, I’ve seen more advanced projects use millis() instead to handle timing.
From a ...
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1
answer
36
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How can I achieve <50 ppm timing with a Sparkfun Artemis ATP?
I want to sample an ADC at very regular intervals. Right now, using millis/micros (which are driven by the internal RC oscillator), I'm off by around 3000 ppm, and it drifts.
Here are some things that ...
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1
answer
75
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MKR1010 Interference when relay motor engages?
I am a complete beginner. Are Arduino products really flaky?
I've thrown together the circuit in the diagram - an MKR1010 in a relay shield. I've wired up 2 sets of sensors, an LCD screen and a motor. ...
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1
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1
answer
63
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Is there a way to use symbolic names for debug watch of RISC-V registers?
Re debugging RISC-V CH32V2xx/CH32V3xx
Is there a way to watch 'RCC_CFGR0', say, rather than '* 0x40021004'?
eg. add definitions to GDB?
(program compiled with -g option and optimized for debug, IDE 2....
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1
answer
152
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Error in Compiling for Seeed Xiao nRF52840 [closed]
I am using Arduino IDE 2.3.4 to program a XIAO nRF52840 Sense. I added the board using the instructions on the official getting started page.
After installing the board in Arduino IDE, I open up the ...
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1
vote
1
answer
96
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include directive for external libraries
I added the Adafruit_GFX_Library to my Windows.
I used Arduino IDE, Tools > Manage Libraries > Install.
In preferences, Sketchbook location is set to d:\Alex\Hobbies\Electronic\Learning Arduino\...
- 121
0
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0
answers
65
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ESP32 - SIM7000G and TinyGSM response from server stuck/delayed with multipart/form-data POST request
I am experiencing a delay in receiving the HTTP POST request body when sending data over a TCP connection using the TinyGSM library with a SIM7000G and an ESP32 (LilyGo T-SIM7000G).
Below is my ...
- 243
0
votes
0
answers
35
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WeMos connection to SinricPro
I am using a WeMos Wifi ESP8266 with a DHT11 sensor to measure temperature and humidity in my house and send them to SinricPro. Alexa then reads from here and uses them to answer to the question "...
- 109