Solar-powered ESP32-C3 predator deterrent with PIR trigger, 5 V LED boost driver, audio amplifier, battery charging, and 60 mm x 45 mm 2-layer hand-solderable layout.

This project is a reference design based on the BQ24295, a single cell Li-Ion battery charger. It manages the power between an external power source (VIN), a Li-Ion battery (BAT), and a system power rail (SYS). Key features include power-path management, battery thermistor monitoring, and charge status indication. #project #BQ24295 #ReferenceDesign #charger #BatteryManagement #referenceDesign #bms #texas-instruments #template #reference-design #polygon

This circuit is an ultrasonic distance meter based on an ATTiny2313 microcontroller. It uses an HC-SR04 ultrasonic sensor to measure distance and displays the results on an OLED display. The power supply is constructed using a Boost converter (TPS613222A) and a 2-cell AA battery. Additionally, it also includes ISP for programming, RESET and START switches, and LED indicators. #project #Template #projectTemplate #ultrasonic #OLED #arduino #attiny2313 #TPS613222A #ISP #referenceDesign #simple-embedded #microchip #template #reference-design .

Power management board for a low-power embedded system with solar panel, 1S LiPo battery, and USB 2.0 inputs; charges the battery from available external power, powers the system from battery when external sources are absent, prioritizes USB over solar, and generates selectable boosted 12V or 5V output plus a regulated 3.3V rail.

Power management board for a low-power embedded system with solar panel, 1S LiPo battery, and USB 2.0 inputs; charges the battery from available external power, powers the system from battery when external sources are absent, prioritizes USB over solar, and generates selectable boosted 12V or 5V output plus a regulated 3.3V rail.

Compact 60 mm x 40 mm child safety wearable PCB with ESP32-S3, SIM800L GSM, NEO-6M GPS, MPU-6050, MAX30102, USB-C charging/programming, LiPo battery input, and test-pointed I2C/UART power rails. Target layout is 2-layer with all components on top, bottom ground plane, short direct I2C/UART routing, and GSM placement isolated from GPS and sensor sections.

Beginner-friendly breadboard schematic for an Arduino Uno driving exactly three servo headers from a separate 4xAA battery pack with shared ground and clear wiring labels.

This is the circuit for Microdriver that is used for 3.7V Li-ion battery with Maintain and Non-maintain mode.

Low-power ESP32 audio/radio device with SA828 walkie-talkie module, MAX9814 microphone, PAM8403-driven GD14 bone-conduction output, and single-cell Li-ion charging, power-path, 3.3 V regulation, and battery monitoring.

This is a LoRa-based door and window sensor incorporating a microcontroller unit (MCU). It features a reed sensor, LED indicators, a AAA non-rechargeable battery, and a booster IC for constant voltage. The MCU is linked to peripherals through nets, ensuring optimal performance #LoRa #MCU #ReferenceDesign #project #referenceDesign #simple-embedded #seeed #seeed-studio #template #reference-design

Automotive smart fuel pump controller with >12 V battery qualification, protected battery input, analog FSCM command following, 25 A current sensing, thermal/fault indication, blue/red LED signaling, and 5-second buzzer alert. Control and fault nets are explicitly terminated to avoid floating or undriven states; any intentionally provisional control nodes are weakly biased to safe defaults during refinement.

Raspberry Pi-based drone control PCB focused on mission endurance for an assumed 10 km travel mission. Camera-specific circuitry and storage subsystems are removed. The Raspberry Pi remains the central processing unit and interfaces to power management, RF telemetry/control, GNSS, IMU, ESC/PWM outputs, battery monitoring, and debug interfaces. Assumption: the 10 km requirement is treated as mission travel/range rather than 10 km altitude, subject to later airframe and regulatory review.

4-layer marine GPS timing and communication device using nRF52840, u-blox ZED-F9P GNSS with external active antenna via u.FL, 915 MHz LoRa radio, Li-ion battery with USB-C charging, separate clean GNSS LDO and digital 3.3V rail, SPI memory LCD, RGB LEDs, buzzer, and 6-axis IMU. PCB target is a 70 mm circular layout with strict RF zoning, dedicated ground plane, 50 ohm RF traces, physical separation between GNSS and LoRa, and low-noise placement suitable for harsh marine environments.

This is a smart watch project based on E73-2G4M04S1A module with SoC nRF52810 on board. OLED display and coin battery #wearable #nRF52810 #E73 #Ebyte #BLE #referenceDesign

XIAO nRF52840 Breakout with Centered Accelerometer, Precision Mounting Holes, and Additional Battery Connector

Passive BLE tracker locator with ESP32-S3, 2.4-inch TFT UI, USB-C charging, LiPo battery power, GNSS logging, 2.4 GHz BLE/Wi-Fi energy detection, passive BLE advertisement identification in firmware, and optional ADL5904 cellular-band sensing.

Bluetooth RC car controller using ESP32-WROOM-32E, TB6612FNG dual H-bridge, XL4015 5V buck module, DC barrel battery input, dual 2-pin motor screw terminals, 1000uF VM bulk capacitor, 100nF decoupling, 10k EN pull-up, 30 mil power traces, 10 mil signal traces, and ESP32 antenna edge keep-out.

Portable Raspberry Pi Pico and NEO-6M GPS tracker powered by a single-cell Li-ion battery, with USB-C charging input, CC resistors, and USB-line ESD protection. Designed to support about 65 mA active current and roughly 30 hours from a 2000 mAh cell, following the performance targets from the evaluation paper.

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.

Two-channel symmetric line follower robot, dual CNY70 sensor front-end with mirrored 2N2222A motor drive stages and central 8V battery input

Bilateral smart running insole data logger using two nearly identical ESP32-S3 pressure-sensing PCBs. Left variant is an ESP-NOW slave without microSD; right variant is the master with microSD logging. Both preserve the 16-zone FSR mux front end, LiPo charging, AP2112K regulation, USB-C charging input, JST battery connector, and the 280mm x 90mm 2-layer low-profile insole form factor.

Compact 2S Li-ion charger for Sony NP-FZ100 battery using DC input, 8.4 V CC/CV charging, automatic termination, reverse polarity, overvoltage, overcurrent, and thermal protection, with defined B+ and B- battery outputs and PCB-buildable component choices.

Cow health-monitoring wearable PCB for a cow-mounted device. Rear strap electronics target 20-25 g and front sensing assembly target about 15 g. Uses an ESP32-based sensor controller, 200 mAh LiPo battery, battery charging circuitry, and interfaces for ammonia, methane, IR temperature, and saliva sensing. Design must tolerate moisture, mucus, debris, vibration, fur contact, and tongue/lick exposure while remaining compact and lightweight for wearable use.

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.

Wearable health device prototype schematic with ECG sensing via AD8232, motion sensing via BNO085 or BMI270 IMU breakout, on-board processing using TI TM4C123G LaunchPad or MSPM0G3507 LaunchPad, optional ESP8266 Wi-Fi, LiPo battery charging with MCP73831, regulated 3.3 V power from TPS63031 buck-boost or AP2112 LDO prototype option, and user interfaces including electrode connector, JST battery connector, programming header, and optional on/off switch.

Production-defensible Rev B ear tag tracker using nRF9151 with separate LTE and GNSS antennas, solar-assisted LiPo charging, battery protection, SPI NOR flash, NFC, eSIM, I2C sensors, Tag-Connect SWD, grouped EVT test points, and RF/power zoning on a 40 mm x 24 mm 4-layer PCB.

Misty Pink Replicator schematic finalized for layout handoff with ESP32-S3, USB-C battery charging, T5838 always-on wake microphone, CI1302 backup ASR analog microphone front end, HTEW0154T8 SPI e-ink display, standardized power/test nets, and final ERC-clean baseline.

Gay Teal P.K.E. Meter with MP2650 USB-C battery charger section finalized, including 1.5uH power inductor and current-sense monitoring filter placeholders for later integration.

Gay Teal P.K.E. Meter with MP2650 USB-C battery charger section finalized, including 1.5uH power inductor and current-sense monitoring filter placeholders for later integration.

ESP32 DevKitC-32 Carrier PCB (No Grove, No Battery LED Bargraph, No Button)

Tiny MSR Card Reader - Always-On Battery Low Power, Encrypted Storage + Encrypted SMS

PS5-Diagnose-Power-Supply-Stick - Battery boost 12V + ESP32 control

6x Warm-White 5mm LED Ring (2 constant, 4 flicker) on 4.5 V battery w/ high-side SPST and bussed 6x330 ohm resistor network

The "Green Dot 2040E5" Board is a Node that interfaces RS485 Sensor probes and can log information to the cloud using LoRa Connectivity. It uses the XIAO RP2040 and the LoRa-E5 (STM32WLE5JC) modules from Seeed Studio to do its magic. It also has amazing power management capabilities (Solar charging, Battery protection, etc) that make it very useful for IoT applications #internetOfThings #smartHomeDevices #SeeedStudio #XIAO #LoRa #RP2040 #IoT

3.3V ESP32-S3 Dual 6V Rail MOSFET Board with MCP23017 I2C Expanders, Option C Gate Network, SW2 DPST Rail-Interlock, 2S LiFePO4 Charger/BMS (BQ24618 + BQ29209) with Series Battery Wiring and Charge Integration, and 2×10 RA Headers (#MCP23017_3V3 #OptionC #GateNetwork #RailInterlock #Dual6V #BQ24618 #BQ29209 #2S #LiFePO4 #SeriesBattery #ChargeIntegration #RAHeaders)

Two-Bank 6 V Igniter Firing System with Onboard 2S LiFePO4 Pack, S-8252A Protection, BQ24618 LiFePO4 Charger (3 A, 3.6 V Fast, <50 mA Termination, 3.8 V HPPC, 3.5 V Float), 32 SOT-223 MOSFET Outputs via MCP23017, with Reserved PCB Areas for Dual 26650 Holders, 34-pin IDC, and Barrel Jack Input #LiFePO4 #Battery #BMS

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

9V Battery 1 Hz LED Blinker Using DIP-8 NE555 (THT) with SPST Switch and Reverse-Polarity Protection

Compact MPPT Solar-Powered Dusk-to-Dawn 0.5 W LED Light with NCP3065 SEPIC Buck-Boost Driver, BQ24650 MPPT Charger, MIC845 Comparator, Vertical JST-PH 2-Pin Battery Connector, Off-Board Solar Input Pads/Optional Connector, Centered Backside LED, 1.4 mm Perimeter Clearance #SEPIC #NCP3065

Smart Wellhead Controller V1.1: ESP32 + LoRa Industrial IoT Node with Solar Power, Deep-Sleep Leak Sensing, and OLED HMI. Now upgraded with a solar charging and battery management stage featuring a TP4056/CN3791 charger IC, power-path switching, Li-ion battery protection, and integrated 3.3 V rail supply. #PowerBlock #SolarCharging #BMS

Low-Power USB-C (5 V) Environmental Sensor Node with 18650 Li-Ion Power-Path, Robust Protection (Reverse Polarity, OVP, UVLO, OCP to 3 A), Dual-Radio ESP32-S3 MCU, I²C VOC/Temp/Humidity/Pressure/Lux Sensors, and 2-/4-Pin JST-XH Expansion Pads for Battery and Sensors #USB-C #LiIon #ESP32 #I2C #PowerProtection #EnvironmentalSensor

PaymentSoundBOX – ESP32 MQTT-Enabled Battery Audio Notifier with Isolated Power, I2S Audio Chain & Integrated UI

Project Description: The Sweet Tomato Heat-Ray project focuses on the development of an advanced PCB design for the PawPulse Smart Collar – a dual-SoC device that integrates both BLE and cellular connectivity. The design features a compact 49mm x 35mm, 6-layer FR-4 board with optimized RF performance, robust power supply management, and critical layout considerations including precise keepout zones for antennas and optical paths. All mechanical and assembly aspects, including rounded corners and optimized signal routing using 0201, 0402, and 0603 components, have been meticulously documented. Note: Please be aware that the battery and its supporting components are not yet included. It is essential to add these components in future revisions to ensure full functionality and compliance with power requirements. #SmartCollar #PCBDesign #BatteryIntegration #ElectronicsDevelopment #RFDesign #InnovativeTech

Ultra-Compact ESP32 Robotic Control Module with 3S Battery, USB-C PD, 4WD Motor & Servo Support, and Integrated GPS/IMU

ESP32-C3 Smart 3S Li-ion/LiPo Battery Management System with Per-Cell Monitoring and Protection

Seeed Studio XIAO nRF54L15 Board (Pin Header Removed, JST-PH Battery, Pushbutton Added)

Ultra-Compact 4-Layer ESP32-C6 + Quectel EG912U LTE Dev Board w/ Onboard eSIM, π-Match RF Tuning, Optional u.FL, USB-C Data (ESP32-C6 Only), USB-C Battery Charging, Controlled Impedance Routing #EG912U #USBDataOnly #USBCharging #4Layer #eSIM

Optimized EMI Synchronous Buck Converter for CC/CV 4S4P Li-ion Battery Charging & Load Testing (150W, 18–60V to 16.8V/11.5A)

High-Current 28V 7S Li-Ion Battery Management System with Integrated CAN J1939 and Advanced Power Management