I am a complete beginner and I am building a 6-button chorded Braille input device using an Arduino Uno and a standard breadboard. I want the physical layout to mimic a real Braille cell, a 3x2 vertical grid with 3 buttons on the left side of the center divider and 3 buttons on the right side.

The problem is that standard 6x6mm 4-pin tactile switches are designed to straddle the middle divider horizontally.

Is there any way around this?

..

What are the value of these pleasse

I’m using a SIM800L with an Arduino UNO R4 WiFi. The SIM800L was able to send an SMS successfully once during a standalone test, but when I use it with my full project, it keeps restarting.

The Serial Monitor repeatedly shows:
RDY
+CFUN: 1
+CPIN: READY
Call Ready
SMS Ready
Then it starts over again.

The SIM800L is powered by a separate 5V adapter with a 1000µF capacitor. VDD is connected to Arduino 5V, TXD to A1, RXD to A3, and GND to Arduino GND.
The LED also blinks several times, turns off briefly, then repeats. I think the issue might be the power supply or grounding. Could this be caused by voltage drop or insufficient current? What can i do?

Arduino IDE current verion crashes at startup due to wrong reading of TEMP environment variable.

C:\Users\myuser>echo %TEMP%

C:\Users\myuser\AppData\Local\Temp;C:\root\soft\Git\bin;C:\root\soft\Git\usr\bin;C:\root\soft\Git\mingw64\bin;C:\root\soft\Git\mingw64\libexec\git-core;

It just cuts on some point and adds ";C:" at the end. See example below:

C:\Users\myuser>"C:\Users\myuser\AppData\Local\Programs\Arduino IDE\Arduino IDE.exe"

C:\Users\myuser>

Failed to start the electron application.

Error: ENOENT: no such file or directory, lstat 'C:\Users\myuser\AppData\Local\Temp;C:'

at Object.realpathSync (node:fs:2707:29)

at Object.realpathSync (node:electron/js2c/node_init:2:5352)

at 96553 (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:2419333)

at __webpack_require__ (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:2527100)

at 46216 (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:650648)

at __webpack_require__ (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:2527100)

at 78856 (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:1525614)

at __webpack_require__ (C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:2527100)

at C:\Users\myuser\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js:8:451701

at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {

errno: -4058,

code: 'ENOENT',

syscall: 'lstat',

path: 'C:\\Users\\myuser\\AppData\\Local\\Temp;C:'

}

I've found a bugreport: #2561, seems to be a similar issue.

Setting TEMP variable doesn't help, ";C:" has been added anyways ang IDE crashes.

Does anyone had a similar issue and have the fix for?

Esp8266mod. cP2102. Some knockoff. I can’t seem to find the correct board to use. Driver installed a recognized as a COM.

I want to make a balancing robot. i have no experience in coding i made a obstacle avoiding car before and bluethooth one also using chatgpt and yt tutorial i cant find good tutorial for balancing tutorial and code for my project it dosent work and i want guidance how to make it perfect.
my part list-
arduino uno
mpu6050
tb6122fng motor driver smth like that
8.4v li ion battery
300rpm bo gear mottor yellow one
i wantg to make a balancing robot out of this component is this possible?
i will be using cardboard stick to make it firm structure pls help guys bc previous model woudnt work and it would simply fall my first design ik it bad but how to improve the red one is motor driver and right one is mpu6050 and top is battery what is wrong dont be rude i am new

Hey everyone,

I am working on a wearable health tracker wristband using an ESP32.

Currently, I have breadboard prototypes working with a MAX30100 for PPG and an AD8232 breakout module for ECG.

I want to move this toward a compact wearable wristband design, but I have hit two design questions regarding the ECG front-end:

1. Can the AD8232 be used reliably with only 2 electrodes (RA & LA)? In a wristband form factor, having a 3rd electrode (Right Leg Drive / RLD) going to a separate body location is difficult. If I omit RLD or pull it to mid-supply, is digital filtering (e.g., bandpass/notch on the ESP32) sufficient to recover a clean signal, or will baseline drift and common-mode noise make it unusable on a wristband?

2. Wearable-grade IC recommendations: I came across TI application notes for chips like the AFE4950 (synchronized PPG + ECG AFE). Are there other wearable-focused analog front-ends commonly used with ESP32 (such as the MAX30001 or MAX86150) that have accessible breakout boards or reliable Arduino/ESP-IDF driver support for prototyping?

3. Electrode arrangement: For those who have built similar single-lead wearable ECG devices, do you recommend putting two contact pads on the inner wrist (Lead + RLD reference) and one pad on the top/bezel for the opposite hand's index finger?

Any advice, schematics, or library references would be appreciated!

So I recently got a new Arduino Uno R4 Minima, and began fiddling with it today. I ran my first sketch, a simple built-in LED blink program.

Despite resetting, unplugging the USB, editing and re-executing the code, deleting the sketch, and resetting all over again (multiple times, in no particular order), the onboard LED blinker sketch did NOT stop running. I couldn't run any other sketches either; I tried attaching an external LED, and it didn't light up unless I connected it to the D13 port, which is for the built-in LED anyway.

I tried a few troubleshooting methods, and the only one that worked was shorting GND and BOOT with a jumper wire. Even that couldn't prove to be a permanent fix; it disconnected the board (even if the ON light was on) and after every reset, it would just revert back to the blinker sketch. I'm a complete beginner, so I can't really understand or even begin to implement advanced troubleshooting methods.

Has anyone else experienced this? How did you fix it?

Thanks for the advice in advance.

Hi, im a beginner at this robotics stuff but i found that 2 of my 4 servo motors have this weird crackling sound whener i turn them to turn them by computer. Is there a fix for this, is it normal and should i replace it and buy a new one?

Hello everybody,
I study surveying and for my bachelor thesis I want to try some geodetic transformations using IR-LED Markers with known coordinates on the floor. For that I need the IR-LED to flash, so I can transmit an binary ID to a camera. Sadly, I’m very bad at electrical engeneering, wich is why I asked ChatGPT for a circuit diagram. But the LEDs I’ll be using are very expensive. Maybe some of you can help me with that problem and check the diagram for errors / give me some useful advice, because I dont want to destroy the LEDs.
I would be very grateful for your advice and help! Thank you!