Compact 2-layer ESP32-S3-MINI-1 piezo TX/RX board for a shared 3 MHz transducer node. Includes USB 5 V input, TP4056 single-cell LiPo charging, TLV75533 3.3 V regulation, ferrite-bead isolated 3V3_ANALOG rail, ~12 V pulsed TX boost rail, low-gate-charge NMOS transmit driver, clamp-protected RX input, 2-stage OPA836 analog receive chain, envelope detector, ADC interface, TMP117 I2C temperature sensor, and status LEDs. Layout intent: piezo centered, RX chain within 10 mm of PIEZO_NODE, boost section remote from RX, digital and analog partitioning, and AGND/DGND star connection near RX front end.

ESP32-S3 touch display development board standardized on a portrait ILI9341 TFT by default, preserving USB-C power, CP2102N USB-UART, I2C touch, PCM5102A audio, microSD, and expansion while assigning KEY1-KEY5 to BOOT, RESET, USER1, USER2, and USER3. The next design pass is driven by a portrait-oriented board resize and user-facing edge placement of the display area, touch interface, controls, and primary connector access.

Multi-layer circular BLDC motor controller for a 24 V, up to 750 W system using an ESP32-WROOM with DRV8323RS gate driver, six external MOSFETs, 2 mOhm shunt current sensing, bottom-mounted AS5600 encoder, USB-C programming/user interface, 3.3 V logic powered from the DRV8323RS buck regulator, and heavy motor phase pads sized for approximately 30 A current paths. Target layout is a circular board around 50 mm diameter, expandable if required for thermal management, power routing, and signal integrity.

This project is a BLE door and window sensor design that uses a U-blox BMD-330-A-R for BLE communication, a reed switch as a sensor, a multi-color LED for status display, and is powered by VBAT. There's also a programming interface and reset switch included. #WiFi #BLE #MCU #ReferenceDesign #project #referenceDesign #simple-embedded #ublox #template #reference-design

This project is a BLE door and window sensor design that uses a U-blox BMD-330-A-R for BLE communication, a reed switch as a sensor, a multi-color LED for status display, and is powered by VBAT. There's also a programming interface and reset switch included. #WiFi #BLE #MCU #ReferenceDesign #project #referenceDesign #simple-embedded #ublox #template #reference-design

Carte STM32F103 2 couches avec alimentation 3,3 V régulée, quartz 16 MHz, USB 2.0 Full-Speed, interface SWD et support de fabrication.

Experimental 21V/5S Li-ion DeWalt battery charger with 21V DC input, relay-switched charge path, tap monitoring, ESP32-WROOM external controller interface, test header, and 2-layer prototype PCB intent.

Raspberry Pi 5 HAT for the Tense Sapphire P.K.E. Meter with two GPIO-driven LEDs, one buzzer, and two GPIO buttons on the 40-pin HAT interface.

Handheld Xbox 360 system with integrated controller electronics, battery-managed USB-C PD power, and a separate dock that automatically switches display, Kinect, and DVD drive paths through a mezzanine docking interface.

Glove interface board using Seeed Studio XIAO ESP32S3. Manufacturing path updated for partial assembly: preserve existing glove interface circuitry (FSR inputs on J3-J7, I2C on J8, SPI on J9, pull resistors R1-R7, decoupling C1) and source U1 separately because JLCPCB stock for MPN 113991114 is unavailable. Assemble all other parts normally, leave U1 for customer-supplied/manual installation, and do not substitute U1 unless a verified XIAO-format pin-compatible replacement is explicitly approved.

FlowState Headband EVT1 — 4-Channel EEG Calibration Device Closed-loop EEG neurofeedback headband for theta/beta baseline calibration. 4-layer mixed-signal PCB, 40x30mm. Core ICs: - ADS1299-4PAG (TI) — 4-channel 24-bit EEG analog front end, SPI interface, 250 SPS - nRF5340 (Nordic) — Dual-core BLE 5.3 SoC, 128 MHz app core + 64 MHz network core Key requirements: - Separate analog and digital power domains (dual LDO: LP5907 for AVDD, AP2112 for DVDD) - Split analog/digital ground planes with single-point connection - 6 electrode inputs (4 active + 1 reference + 1 DRL) with individual TVS ESD protection on each - LIS2DH12 accelerometer (I2C) for motion artifact detection - MCP73831 USB-C battery charging (300-500 mAh LiPo) - 2.4 GHz chip antenna or PCB trace antenna at board edge with 10mm keepout - Conformal coating for sweat/moisture protection Reference designs: - Analog front-end: TI ADS1299 EVM (SBAS499) - Digital/BLE: Nordic nRF5340 DK reference schematic Critical constraint: Microvolt-level EEG signals — analog input routing and power supply filtering are the highest-priority layout concerns.

Wearable closed-loop ultrasonic monitoring and transcutaneous neuromodulation system based on ESP32-C3, powered from a 7.4 V 1000 mAh LiPo battery with TP4056 charging, MT3608 boost conversion, AMS1117-3.3 regulation, JSN-SR04T ultrasonic sensing, LED and buzzer alerts through a BC547 driver, and a reserved neuromodulation interface for future integration.

Datasheet-driven MFRC522 RFID reader PCB intended to replicate RC522 module behavior at 13.56 MHz with a 3.3 V nominal supply, 2.5 V to 3.3 V operating range, and RC522-style 8-pin host header compatibility. The MFRC522 datasheet is the authoritative source for pin usage, power rail relationships, oscillator requirements, reset/IRQ handling, and antenna interface topology. AVDD, DVDD, and TVDD must be tied to the same 3.3 V rail; PVDD must be equal to or lower than DVDD; unused MFIN must be tied to SVDD or PVSS; SVDD must be tied to a valid supply if not used independently. The design must use a 27.12 MHz crystal meeting CL 10 pF and ESR <= 100 ohms, local 100 nF decoupling on each MFRC522 supply grouping plus bulk capacitance, and an RF front-end based on the MFRC522 application diagram and reference reader matching/tuning network. PCB priorities are short crystal and RF connections, compact placement of decoupling capacitors at supply pins, solid ground reference, and protected antenna region with minimal digital routing through the RF area.

Driver drowsiness detection ECG front end based on the AD8232 with ECG electrode interface, analog signal conditioning, a dedicated 50 Hz twin-T notch filter for power-line interference rejection, regulated low-noise analog power, and a downstream conditioned ECG output prepared for processing and fatigue/drowsiness analysis.

MagicGlow smart key tray annular PCB with dual WS2812B rings, ESP32-C6 control, HX711 load-cell interface, USB-C power/UART access, buzzer, and button.

Self-Powered RF Transceiver Module for EM Sensing with RF Prescaler, Divider Chain, and ESP32-S3 Interface

Single-project implementation of the Blue Ant AMP Architecture Rev2 using one shared schematic with six logical board partitions: PCB-01 phono stage, PCB-02 input selector and relay attenuator interface, PCB-03 balanced driver and RCA-to-balanced conversion interface, PCB-04 dual logical power amplifier channels, PCB-05 multi-rail power supply, and PCB-06 isolated control and display. Explicit inter-partition connector interfaces and named nets preserve balanced signal handling after RCA conversion, distinct rail domains (+63V, -63V, +15V, -15V, +5V, +3.3V), and documented hard constraints including low-noise analog isolation and high-voltage domain separation.

XIAO-Compatible 915MHz RF Shield with Wio-LR1121 Module and u.FL Interface

INTENT: medium complexity / high density USECASE: potential torture test for trace suggestions while routing vs/ routing the entire board; can incremental trace suggestions still be useful (how much context do they need to consider to be good), or does this only make sense as a whole-board problem given the density challenges? ––––––––––––––––––––––––– OBD2 to UART interface dev board. Alternative to deprecated ELM237 Chipset. Documentation: - Power tree: https://drive.google.com/file/d/1oG5_56AuaiLtG3buUaOyhg63TMySnYF3/view?usp=sharing

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SmartDeskPet v1.0 Shield Stage 1 status: - Goal: 5V input -> dual AMS1117-3.3 rails (+3V3_MCU and +3V3_WIFI) with common GND. - Note: Keep power nets explicitly named (avoid unnamed nets) to keep ERC happy. Stage 1 completion checklist: - Mark J1 Pin_1 (+5V) as a Power Output pin to satisfy ERC power-driver checks. - Verify all GND symbols/returns are on the same GND net. - Keep +5V_SERVO isolated from the main +5V net (only share GND). Stage 2 preparation notes (MPN/LCSC + layout constraints): - MPN/LCSC targets to define before Stage 2 exit: - AMS1117-3.3 (SOT-223): set exact MPN and (optionally) LCSC PN for both U1 and U2. - 100nF capacitor (0603): set MPN/LCSC for all 0603 100nF decouplers. - 4.7k resistor (0603): set MPN/LCSC for I2C pull-ups R1 and R2. - 1000uF bulk capacitor (radial): set MPN/LCSC for C7 (CP_Radial_D10.0mm_P5.00mm). - DC005 power jack/regulator input: select exact DC005 footprint + MPN/LCSC (if used). - 2.54mm headers/sockets: set MPN/LCSC for H1, H2, J1, J3, J4, J5, P3, P4, P5, and J2. - ESP-01S antenna keepout: - Reserve a copper keepout under and in front of the ESP-01S onboard antenna. - No copper pours/traces/components in the antenna region (top and bottom) per module guidelines. - H1/H2 header spacing: - Maintain 1000 mil spacing between H1 and H2 header centerlines (shield mechanical requirement). - Silkscreen placeholders: - Add silkscreen labels for: 5V IN, GND, +3V3_MCU, +3V3_WIFI, SERVO1, SERVO2, I2C SDA/SCL, DHT11, ASRPRO UART2, ESP-01S UART3. - Add placeholder text for: MPN, LCSC, board revision, and date code. Stage 3 layout constraints (placement and routing guidance): - Connector placement strategy: - Place H1 and H2 first to lock the shield mechanical interface; enforce 1000 mil spacing. - Place J1 and any DC005 input at the board edge for easy access. - Designated power area planning: - Group U1, U2, and C7 near the 5V entry point; keep high-current 5V and regulator loops short. - Use wide copper for +5V and any servo supply; stitch GND around power section. - Antenna keepout boundaries: - Place J2 (ESP-01S socket) at a board edge with the antenna facing outward. - Enforce a top-and-bottom copper keepout in the antenna region; keep noisy power traces away.

Architectural Lavender Translation Collar – ESP32‑S3 Wi‑Fi + LoRa, USB‑C, Li‑ion, low‑power design Overview Experience a cutting-edge IoT solution with this low‑power board built around the ESP32‑S3‑MINI‑1‑N8. Designed for seamless Wi‑Fi (2.4 GHz), BLE, and LoRa (868 MHz) connectivity, this board integrates ENS161 and ENS210 sensors over I2C alongside an RFM95W‑868 LoRa radio on SPI. It is powered via a 3.7 V Li‑ion cell with USB‑C charging up to 500 mA, complete with full battery protection, a robust 3.3 V rail tailored for Wi‑Fi burst currents, and per‑peripheral power gating to enhance energy efficiency. Core Features • MCU: ESP32‑S3‑MINI‑1‑N8 equipped with an onboard PCB antenna for 2.4 GHz Wi‑Fi/BLE, ensuring optimal wireless performance. • Sensors: Integrated ENS161 and ENS210 sensors utilize a shared I2C bus with controllable 4.7 kΩ pull‑ups for streamlined communication. • LoRa Radio: The RFM95W‑868 module, connected via SPI, enables long‑range communication at 868 MHz. Power & USB‑C Connectivity • Battery: A reliable 3.7 V 1200 mAh Li‑ion battery connected via a right‑angle JST‑PH 2‑pin connector features built‑in battery protection. • Charging: The USB‑C receptacle, with CC resistors and TVS protection on D+/D− along with series resistors, supports fast, safe charging with a current limit of 500 mA. • Regulation: A dedicated 3.3 V regulator capable of handling Wi‑Fi burst currents coupled with bulk and high‑frequency decoupling ensures stable operation, supported by status LEDs indicating power and charge states. Low‑Power Control • Peripheral Management: Load switches allow selective power‑gating of the ENS161, ENS210, and RFM95W modules, controlled directly by ESP32‑S3 GPIOs. • Energy Efficiency: Controllable I2C pull‑ups minimize idle current, vital for prolonged battery life in IoT applications. RF and Antenna Integration • 2.4 GHz: Utilizes the integrated PCB antenna on the ESP32‑S3 with proper ground/metal keep‑out zones for optimal signal integrity. • 868 MHz: Features a controlled‑impedance feed from the RFM95W to a PI matching network (C‑L‑C pads) with flexible antenna options—selectable via SMA connector, chip antenna, or PCB trace—and includes RF ESD protection. Connectivity & Debug Features • USB‑C Interface: Provides secure data connectivity with integrated safeguards and proper terminations. • Debugging: A comprehensive programming/debug header exposes EN, BOOT, and UART lines, with test points on key rails and buses (3V3, VBAT, SCK, MOSI, MISO, SDA, SCL, RESET/EN, GND) to simplify development and troubleshooting. Design Verification • Rigorous ERC/DRC and decoupling checks ensure adherence to component ratings and optimal signal routing. • Maintain RF keep‑outs and impedance‑controlled traces for both 2.4 GHz and 868 MHz paths, securing reliable performance even during high‑intensity operations. #IoT #ESP32S3 #LoRa #LowPowerDesign #USB-C #WirelessConnectivity #BatteryPowered #RFDesign

Surprised Bronze Universal Remote with ESP32-C3 Co-Processor, 8080 8-bit LCD Interface, and Remapped UART Interconnects

SDI-12 Open-Collector Interface on Swan GPIO D5

8-Channel Wearable BLE5 Brain–Computer Interface with 24-bit Biopotential AFE and Cross-Platform SDKs