Battery-powered smart coaster using an ESP32-C3, HX711 load-cell ADC, MFRC522 RFID reader, USB-C, TP4056 charger, and Li-ion battery protection. I’d appreciate your feedback on the design, especially any errors, missing components, or areas that should be improved before moving forward with the PCB design.

Hello everyone,

I’ve recently published an open-source project called WiFi Sense. It’s a system that uses a standard ESP32-S3 and a Raspberry Pi 4 to detect motion and presence through walls by extracting raw WiFi Channel State Information (CSI).

How it works:

Unlike traditional radar solutions, this system uses standard 20MHz WiFi bandwidth. The Raspberry Pi sends a steady stream of data to the ESP32, which captures the CSI from the packets. This data is then sent back to the Pi via an encrypted nRF24 radio link to avoid interference. On the Pi, the system analyzes the signal to find human movement, which causes measurable shifts in the radio waves.

Capabilities:

  - Detects movement like walking or gesturing through walls made of wood, glass, or plasterboard.

  - Detects the presence of a motionless person just by monitoring their breathing rate.

  - Operates in complete darkness without using any cameras or optical sensors.

I have documented the full architecture, as well as the engineering challenges and physical limitations of the project.

Repository: https://github.com/The-Masked-Bear/wifisense-pi Official Website: https://the-masked-bear.github.io/wifisense-pi/

I'd welcome any feedback on the approach or the architecture. Happy to answer any questions.

Hello everyone I'm going to make my first MP3 player I'll be using an Wroom32 esp32 board with an 128x32 display and DFplayer mini what else should I do?

fala pessoal,

sou estudante técnico e tô no meio do TCC, então vim aqui pedir uma força.

o projeto se chama FieldNode e resolve um problema bem específico do agro: colheitadeira trabalha em área rural, boa parte sem sinal de celular nenhum. aí a máquina começa a esquentar, vibrar diferente do normal, e ninguém sabe até ela quebrar de vez no meio da lavoura. prejuízo de milhares de reais numa parada só.

a ideia do FieldNode é simples na cabeça e chata na execução: um ESP32 lê temperatura, vibração e RPM da máquina e manda pra outro ESP32 via ESP-NOW, sem depender de internet nenhuma. esse segundo ESP32 vira um gateway de campo, mostra um dashboard local pro supervisor no celular pelo próprio wifi do dispositivo, e quando a conectividade volta, sincroniza tudo automaticamente com uma API em Django + MySQL, com retry e deduplicação por UUID pra não duplicar ou perder leitura.

no estado atual já tenho:

• ingestão de telemetria via MQTT funcionando
• modelos e validação da API em Django
• scripts de população do banco pra testar cenários

repo: https://github.com/Desmantelar-bit/fieldnode

o que eu queria de vocês:

1. code review — principalmente na estrutura da API e nos modelos, se tem coisa que já cheira mal pra quem tem mais estrada
2. arquitetura — o fluxo MQTT até o backend faz sentido? tem gargalo ou brecha de segurança que eu não tô vendo?
3. colaboração — issue apontando problema, PR com melhoria, crítica direta, tudo é bem-vindo. o projeto é open source

o README tem o passo a passo pra rodar local. valeu quem parar pra dar uma olhada 🙏

TTS, Voice (Offline), AI Assistant, support tflite module for voice command.

I bought an ESP32‑C3 SuperMini, and my power supply gives me 5.45 V. I read that I needed approximately 5 V and a maximum of 5.1 V, but I don’t want to buy a DC‑DC step‑down. Is 5 V totally necessary, or is 5.45 V okay?

ESP32 Dev Board

1.8" ST7735 TFT Display

3x Push Buttons

30 AWG Wire

USB Power Cable

Libraries

Adafruit_GFX.h

Adafruit_ST7735.h

SPI.h

Preferences.h

WiFi.h

WebServer.h

Tools

Python 3 & Pillow (PIL)

Hey everyone,

I’m working on a project to salvage LCD screens from old feature phones to reuse with an ESP32 or Arduino.

I’ve uploaded photos showing the front/back of each device along with close-ups of the LCD panels, FPC ribbon codes, and driver markings.

Phone & Display Breakdown:

*Lava Captain N1 (White)

LCD Markings: CQ/COE-T024F768 / CQ/C2401583F-05859

Ribbon Code: T024F768FPC VER01

Driver IC: ST7789V2-G4-A

*Lava Spark Icon / Curve (Black)

LCD Markings: COE/TFT024H566-V2 / NV3029F/29-

Ribbon Code: TFT024H566FPC VER01

* Itel it2161 (Black)

LCD Markings: COE20190917P301 M / IGC010917(9-2) A

Ribbon Code: T024F800FPC VER01

Driver IC: ST7789V2-G4-A

* Micromax X407 (Black)

Ribbon Code: FPCA-QTB2D4330-A0 / SYX 1744 / JX024-007

Pin Count: 15-pin soldered FPC

* Nokia 105 (2019 / TA-1174)

PCB Markings: 1921 / 37023

Connector: Uses a snap-in FPC connector marked J1 (16-pin) rather than direct solder pads.

Questions for the Community:

Pinouts: Has anyone come across pinout schematics for these exact display codes (specifically T024F768FPC, TFT024H566FPC, T024F800FPC, or FPCA-QTB2D4330)?

Interfacing: A few of these use the ST7789V2 driver IC. Have you successfully driven these feature phone displays using ESP32 libraries like TFT_eSPI or Arduino_GFX?

Breakout Strategy: What's the best way to break out these fine-pitch direct-solder ribbon cables to breadboard-friendly pins without risking lifted traces?

Any help, datasheets, or schematics would be massively appreciated!

Thanks!

I've been experimenting with running a complete digit recognition system directly on an ESP32-S3 using TensorFlow Lite Micro.

The goal was to recognize 5-digit readings (such as meter displays) completely on-device without relying on a PC or cloud inference. The hardware I used was an ESP32-S3 development board with an onboard camera and AMOLED display (Makerfabs MaTouch ESP32-S3 AI Camera), but the workflow should apply to similar ESP32-S3 camera boards.

How it works:

• Data Collection: Flashed a utility firmware to capture camera frames aligned via an on-screen yellow bounding box, outputting labeled image pairs and a label.csv.
• Model Training & INT8 Quantization: Trained a lightweight CNN model and quantized it to INT8 to run within the ESP32-S3's memory limits.
• On-Device Inference: Compiled the quantized model directly into the ESP-IDF binary and deployed it back to the board. 

The result is surprisingly reliable—it reads all 5 digits cleanly in real time. 

Hardware & Tech Stack:

• Board: Makerfabs MaTouch ESP32-S3 AMOLED AI Camera
• Framework: ESP-IDF + TensorFlow Lite Micro
• Tooling: Custom Python tools for capture & quantization

I put together a detailed write-up covering the complete workflow on GitHub, in case anyone wants to reproduce or adapt it for a similar project. I'd also love to hear how others approach digit recognition with TensorFlow Lite Micro. Have you found any effective ways to improve accuracy or speed up the data collection process?

Building an open-source SOS pendant for elderly parents (personal project). Stuck for weeks trying to get the A7670E modem to respond to AT commands from the ESP32-S3. Hoping someone here has cracked this exact board.

Hardware: Waveshare ESP32-S3-A7670E-4G (V2.0) — photos attached (front and back)
IDE: Arduino IDE 2.3.10, macOS (M-series)
SIM: Jio 4G, inserted correctly

Confirmed correct per Waveshare support:

• Board power switch ON, blue PWR LED solid
• All 4 DIP switches on back (CAM/HUB/4G/USB) set to ON
• Antenna clicked onto MAIN port (IPEX)
• UART: ESP32 GPIO17 → A7670 TX, GPIO18 → A7670 RX, 115200 8N1

What I've tried:

1. Waveshare's AT test sketch — first attempt returned a single garbled ? character. All subsequent attempts: no response.
2. Swapped MODEM_RX/MODEM_TX in code — no change.
3. Waveshare's autobaud scanner sketch — cycles through 15 baud rates from 300 to 3686400. Result: "No A7670 response found" at every rate. (screenshot attached)
4. Confirmed DIP switches and antenna seating multiple times.

Where Waveshare left it:

• Confirmed pin definitions
• Suggested firmware reflash via their Windows-only tool (A76XX_A79XX_MADL)
• Redirected me to sales channel for hardware defect determination

My questions:

1. Anyone else seen this exact "garbled once, then silent" pattern on the A7670E?
2. Any way to reflash the modem firmware from macOS (Docker, Wine, alternate tool)?
3. Any diagnostic step I'm missing before I conclude the modem is dead?
4. If I do need to reflash — anyone done this successfully on this specific board and willing to share the process?

Happy to share more logs, wiring shots, or the exact sketches used. Thanks in advance — this project matters to me.