Cost-Effective USB-C 2S Li-Ion Charger with Integrated 1W LED Flashlight - Fully Discrete, Generic Components, Minimalist Design

Handheld computing carrier board for a salvaged CPU module using a 100-pin mezzanine socket, with preserved 2S battery charging, balancing, and service-friendly edge I/O.

Welcome to your new project. Imagine what you can build here.

Heating element temperature controller with 2S battery support and power meter.

Heating element temperature controller with 2S battery support and power meter.

Beginner-prototype solar bee monitor central controller using a plug-in 38-pin ESP32 NodeMCU-32, breakout sensor interfaces, switched camera and gate power, RS-485, monitored rails, and isolated safety-critical 2S charging/protection interfaces pending fully verified implementations.

Industrial Raspberry Pi CM4/CM5-compatible RTK base-station carrier with PoE+, external DC input, BQ25750 2S Li-ion UPS, USB hub, Mosaic-X5 mPCIe GNSS, Quectel EM05 LTE, Ethernet, watchdog, protection, and JLCPCB-focused manufacturing constraints.

Regenerative braking power generation and charging circuit using two DC motor generators, rectification, TVS protection, supercapacitor buffering, a 2S Li-ion buck-boost charger, BMS protection, and regulated 5 V/3.3 V load rails.

Raspberry Pi 4 based AI robot car with camera, four encoder motors, dual TB6612FNG drivers, ToF/ultrasonic/IMU sensors, PCA9685 servo control, and 2S LiPo power through emergency and main switches.

Compact rugged handheld outdoor field-data display/logger with ESP32-C3 WiFi/BLE, transparent PMOLED, BMP280, dual encoders, and protected 2S LiPo power.

Compact ESP32-S3 AI robot controller with DevKitC-1 module, 2S Li-ion power input, 5V buck regulator, optional clean 3.3V rail, TB6612FNG dual motor driver, OV2640 camera FPC, I2S audio, OLED, ultrasonic and TCRT5000 sensor headers, and a compact 2-layer PCB prepared for Gerber export.

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.

Airsoft HPA FCU - 2S VBAT_SOL direct, nRF52 BLE, MOSFET solenoid driver

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

Power supply for 3.3V from a 2S LiPO using an XT30 connector

Bipolar (BJT) Transistor NPN 230V 15A 30MHz 150W Through Hole TO-3P(L) #CommonPartsLibrary #TransistorBJT #2SC5200

30V 1W 30@20mA,2V 3A SOT-89 Bipolar Transistors - BJT ROHS #CommonPartsLibrary #TransistorBJT #NPN

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.