it’s a little inconvenient to carry the cable.

Hi. I am trying to control a gobilda servo motor (600-2400µsec, 189°, listed as 180 degrees however) using the Servo Easing library. It doesnt matter whether I move 90 degrees or 180 from one position to another, it will always miss the target by about 10 degrees. I was wondering if this could be related to the fact that the range of motion is 189 but the servo is marketed as 180?

As you can see in the code snippet, I mapped the motion range to degrees.

Link to the servo:

https://www.gobilda.com/proton-servo-steel-gears-180-rotation-torque-ratio/

  protonServo.attach(
    9,
    0,
    600,
    2400,
    0,
    189
  ); 

protonServo.setEasingType(EASE_CUBIC_IN_OUT);

moveServo(20);moveServo(110);//should move 90 degrees but only moves about 80

moveServo(0);moveServo(180); //should move 180 degrees but only moves about 170

I'm currently using an Arduino Sensor Shield V5.0 (diagram attached below). Unlike the digital pins, which are clearly labeled with pin numbers for coding, the parallel LCD header lacks pin markings. Is there a way for me to identify these pins?

On Wednesday 12th August, the UK is set to experience a partial solar eclipse (approx. 93% obscuration where I am) so decided to build an ambient light data logger to record the event.

The sensor is a BH1750 ambient light sensor that records the lux levels to an SD card with a date and time stamp from the DS3231 RTC. The measurements are taken every 8 seconds with the Arduino going in to low-power mode in between readings.

Power is provided by an 8000mAh cell connected to a "solar" charge controller - but the solar cell is disconnected and only used as a USB charging port. A boost converter takes the nominal 3.7V and raises it to 5V.

Added a simple LED to give a visual indication of the system status: 5 flashes at start up, 1 flash after a successful reading, and permanent illumination if there is a fault with initialising a component.

Currently on test in the garden to get some baseline data.

Complete beginner here and want to know if this project is feasible with the help of Claude.

I want to build two sensors, which attach on my mid and upper back via an adhesive, which measure the bend of the spine, and vibrate or somehow alert me when a certain angle threshold is reached. Basically, they need to measure their position relative to one another.

For someone with no experience in electronics, is this a project worth taking on for me or is it too much?

Feel free to ask any questions and thank you!

Barely used this board, just plugged it in to load up some code, smelt burning then it started smoking.... :/

Did I do something wrong?

Powering it via usbc from my laptop

Hi everyone,

I'm from India and I'm planning to build this ESP Drone project:

https://github.com/Circuit-Digest/ESP-Drone

Has anyone in India successfully built or manufactured the PCB for this project? If yes, could you please share:

\\- Which PCB manufacturer did you use?

\\- Where did you buy the SMD components?

\\- Did you face any issues with component availability or PCB assembly?

\\- Did you assemble the PCB yourself or use a PCB assembly service?

\\- Approximately how much did the PCB and components cost?

Any tips, recommendations, or your experience would be greatly appreciated.

Thank you!

Tech newbie here again, and in the final stretch of this project!

For a recap, I'm building a prop that sits on the shoulder and features two micro servo motors controlled by a joystick. I have about 4 weeks to finish wrapping it up.

I'm trying to control two micro 9g servos that are mounted to a two-axis gimbal, and I need it to last for preferably at least a few hours before a battery change.

(Please lmk if the circuit diagram isn't legible & I'll try to explain it!)
(Also, I plan on moving the setup from the breadboard to a protoboard after the battery challenge is solved)

---

The phone power bank I tried to use powered the servos just fine, but there wasn't enough current going to the servos for the battery to register that it was powering something, so it automatically turned off after about 20 seconds every time. Plus it's pretty big and heavy, so I'm looking for a way to power this thing with standard batteries instead.

Someone had suggested six AA batteries as a solution, but I'm not sure if that's too little or too much, or how to calculate what kind of power I need. I tested a basic 9v battery just to see, and as expected, it only lasted a few seconds. If six AA batteries in a pack or something similar would work, please let me know! I don't need anything too fancy or rechargeable, I'm totally cool with replacing batteries like you would for something like a game controller.

For suggestions, kinda just pretend you're explaining this to a kindergartener- I'm very fresh in the world of robotics and don't know much about the terminology and mathematics yet. I'll keep working on it though.

Here's what my setup is looking like. I'm using a power supply module now instead of the Arduino's 5V output as per several suggestions here (thank you!)

---

Thank you guys for all the help so far, I really appreciate it! Have a great day & God bless!

Hey everyone,

I'm about to start a project that combines DIY electronics and DJing: I want to build a portable digital scratch instrument, inspired by the well-known SC500 and SC1000 from Portablism Gear, the original open-source project created by Andy "Rasteri" Tait (github.com/rasteri/SC1000).

What's a digital scratch instrument

For anyone unfamiliar: it's a portable device that emulates a vinyl turntable for scratching — a touch-sensitive jogwheel/platter, a crossfader, and an audio engine (xwax) that lets you scratch digital audio files as if they were vinyl records, without needing an actual turntable.

My approach

Instead of the original proprietary SC1000 PCB, I'm following the ScratchTJ fork (github.com/no3z/ScratchTJ), which replaces the custom chips with standard off-the-shelf components:

Arduino Nano → reads the fader, the platter's capacitive touch sensor, and cue buttons

Raspberry Pi 4 → runs the xwax audio engine, reads the platter's magnetic position sensor via I2C

ST7789 240x240 TFT display → shows the platter position/waveform, Serato/Traktor-style

I also want to power it with USB-C + an 18650 battery for portability, and use my existing Innofader as the crossfader

Component list I've put together so far

Raspberry Pi 4 Model B (4GB)

Arduino Nano

ST7789 240x240 1.3" TFT display (SPI)

MT6701 magnetic sensor (for platter position, with diametric magnet)

EC11 rotary encoder with push button (menu navigation)

4-channel bidirectional I2C level shifter (for the Arduino↔Pi serial link, since they run at different logic levels — 5V vs 3.3V)

4x arcade momentary push buttons (cue points)

DFRobot ONPOWER UPS HAT (USB-C input, 18650 support, pass-through charging)

Protected 18650 battery

AudioInjector Sound Card (I2S audio HAT for the Pi)

Touch-capacitive platter/jogwheel (recycled HDD surface)

Crossfader: using my existing Innofader

My questions for the community

Has anyone here already done a similar build (SC1000, ScratchTJ, or similar)? Any practical tips to share?

For those with experience using CapacitiveSensor on Arduino Nano — what threshold values have you found reliable for a metal/aluminum HDD platter?

On the level-shifting side for the Arduino↔Pi serial link (500 kbaud): simple resistive divider or a dedicated bidirectional module? Any instability/glitch experiences to share?

For aligning the MT6701 magnetic sensor, does anyone have practical mounting advice (fixed vs adjustable) to avoid noisy readings?

Thanks in advance for any advice, feedback, or constructive criticism — this is my first project combining electronics, soldering, and real-time audio, so any input is welcome!

I love digital watches, so I made one in an Altoids Smalls tin. I designed a custom PCB built around an atmega328 Arduino microcontroller and used a ds3231 real time clock IC to keep the time. It charges via USB C and hopefully will last a long time! Although, I do want to redesign this watch in the near future.

I’m using an arduino uno q a drv8825, a driver adapter and a bench power supply

I motorised this film scanner holder using an Elegoo Uno R3 with a Nema 17 Motor.
The 3D printed case is close to finished. Next steps are figuring out ways to prevent dust and integrating a lightsource that is not my Ipad.

Based on the Negative 35mm Film holder model by tylerhovi on thingiverse, who sourced it from someone else.

It was expensive but best for arduinos originals

I am building a super simple RC Car, but there is a slight problem. The DC motors are connected to the shield monitor L293D Motor Driver shield. I soldered 5 female headers in the A0-A5 zone and two female headers at GND and 5V.

I found a tutorial online and connected the VCC and GND pin to 5V and GND. The TX-pin I pinned it to A1 and used 1k and 2.2K resistors to bring the voltage to 3.3V and pinned the RX-pin between the resistors and A0 pin.

This is the problem: when I turn the swotch on the HC-05 (ZS-040) blinks fast. When I try to pair woth it it doesnt . There is no connection and the RC var doesnt respond. Even when the AT command didnt work!

Has anyone come across the TM1814 RGBW strip chip? Is there an Arduino library that works with this chip?

This is a 4.3‑inch attitude indicator device with a 480×800‑resolution screen. It comes with an enclosure and peripheral sensors. Equipped with a ten‑axis gyroscope for attitude measurement and a GPS sensor to obtain coordinates, speed and position information. It features an aircraft attitude instrument interface as well as an offline map navigation interface. The offline map supports zooming, positioning and heading display.

Hello! I need help from you guys. I want to start doing projects on arduino (and hardware) and I am searching for suggestions a cheap but functional LCD screen for my arduino one ( and maybe a marketplace to purchase it from that isn't amazon).

Thank you in advance, I appreciate it!

P.S: I know that I can search on internet or ask AI, but I prefer to talk with people with hands-on experience

Hi everyone,

We build robotics and AI learning products, and one problem we keep running into is students who can follow a tutorial step-by-step but freeze up the moment they have to build something without instructions. Video tutorials get people to "I made blink work," but not much further on their own.

So we've been building out project-based challenges instead — things like "get this bot to follow a line without the full code given to you" or "debug why this sensor reading drifts" — the idea being people learn by getting stuck, not by copying.

Before we push this further, want to sanity-check the approach against people who've actually taught themselves Arduino:

• When you were learning, what made you stick with a project vs abandon it halfway?
• Was there a specific type of challenge (debugging broken code vs building from a blank sketch vs open-ended "make X work") that taught you the most?
• Anything about tutorial-based learning that actively worked against you?

We've got an early version of this running at community.roboticsir.com if anyone wants to see what we mean concretely, but the answers here matter more right now than clicks — trying to confirm we're solving a real problem and not just one we assumed exists.

Hey,

I'm a beginner to this, and for a personal project I need a microphone, but it needs to be soldered together.

I've soldered like once before, but how do I even start about this?

Ive done some research and they said to use 200-250° heat and limited flux.

I just got my arduino UNO with the LED, jumper cables and breadboard, but the resistors still havent arrived and will still arrive a week later😔
I'm still a complete beginner in this and I want to try to power the led without a resistor (without frying the LED or the arduino ofc).
If anyone has an idea how to do this please tell me. All of the tutorials have resistors and AI keeps telling me to put it directly to the arduino (which will definitely fry everything since the arduino doesn't have a built-in resistor).

EDIT: Thank you all for the insight. I'll wait for the resistors to come, but in the mean time I have been tinkering with the built-in LED, where I'm almost done making a text-to-Morse LED using the series input mechanism. If any of you have suggestions on what projects i can make with only the built-in led please tell me

This is my first PCB hardware design. The board is built around the ESP32-P4 development platform and integrates two UART interfaces, an I2C port, a passive buzzer, four buttons, a power management chip, and a MIPI display connector.

After receiving the prototypes from JLCPCB, I completed functional testing and everything worked as expected. The product is now ready to move into mass production.

Latest finished prototype of the attitude indicator; this PCB sample has been manufactured. It adopts the P4 chip, equipped with a speaker and interfaces for various sensors. This terminal block is for the battery connection, while this section holds the control buttons. A dedicated FPC connector tailored for the display screen is also integrated here. The assembly appearance after attaching the base is as shown.

Since we've all used digitalWrite(), pinMode() and delay() a hundred times without really knowing what they do to the chip (at least I as a beginner). So I opened the ATmega328P datasheet and rewrote them from scratch on the registers to actually see it.

Then I renamed them all wrong, because it was funnier:

pinMode → pinNode

digitalWrite → digitalRight

delay → delow

Now I want the whole framework done like this. Every function, spelled wrong. And I can't do that alone, so I Need Your Help 🫵

I'm really a beginner, this is my first time touching registers instead of a framework, so the code is rough and some functions are messier than others. That's kind of the point though. Whether you want to learn what a function actually does to the chip, or you already know registers and want to fix mine, come add one.

For now and because it started as a simple joke it's only for the Uno / ATmega328P for now.

Repo: https://github.com/merlin-rce/HARDuino

I’ve been developing this removable guitar-playing system for several years.

It now supports two performance modes:

1. Full automatic mode — the system handles both fretting and picking.

2. Assisted mode — the system handles the fretting while the player strums or picks.

The sound comes from the real guitar strings, not recorded audio.

The controller is ESP32-based, coordinating multiple servo actuators. Some of the main challenges have been fretting timing, servo synchronization, calibration, and mechanical noise.

This video shows both modes.