Arduino-compatible pH probe interface using a high-impedance analog buffer and ADS1115 16-bit I2C ADC for improved pH measurement sensitivity.

Compact ESP32-S3 Smart Glasses Starter PCB with OV2640 Camera, I2C Mux, I2S Audio, LiPo Charging, and USB-C Debug Interface

The LoST 3296 board features an Low Power STM32, an RFM95 Module for LoRA connectivity and a connector to interface different sensors. You can hook up a UART module, I2C module and a module using the RS485. The board is powered by the USB-C port

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

series is an industrial-grade general-purpose microcontroller designed based on QingKe RISC-V2A core, which supports 48MHz system main frequency in the product function. The series features wide voltage, single-wire serial debug interface, low-power consumption and ultra-small package. It provides commonly used peripheral functions, built-in 1 group of DMA controller, 1 group of 10-bit analog-to-digital conversion ADC, 1 group of op-amp comparator, multiple timers, standard communication interfaces such as USART, I2C, SPI, etc. The rated operating voltage of the product is 3.3V or 5V, and the operating temperature range is -40℃～85℃ industrial- grade.

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

The RP2350, developed by Raspberry Pi Ltd, is a high-performance microcontroller designed to cater to a broad range of applications requiring efficient power management, advanced security features, and versatile IO options. This microcontroller stands out with its dual-core architecture, featuring either Cortex-M33 or Hazard3 processors operating at up to 150 MHz, ensuring robust performance for complex applications. It boasts a substantial 520 KB of on-chip SRAM distributed across 10 independent banks, enhancing parallel data processing capabilities. Additionally, the RP2350 supports up to 16 MB of external QSPI flash/PSRAM for extensive program and data storage, further expandable via an optional second chip-select. A notable feature of the RP2350 is its integrated on-chip switched-mode power supply, designed to generate core voltage efficiently, complemented by a low-quiescent-current LDO mode for reduced power consumption in sleep states. Security is a paramount feature of the RP2350, offering options for boot signing with key fingerprint in OTP, hardware mitigations against fault injection attacks, and a hardware SHA-256 accelerator for cryptographic operations. The microcontroller is also equipped with a comprehensive set of peripherals, including USB 1.1 controller and PHY, multiple UARTs, SPI, and I2C controllers, 24 PWM channels, and 12 programmable IO (PIO) state machines, providing extensive interface capabilities. The RP2350 is available in QFN-60 and QFN-80 packages, with or without flash-in-package options, catering to various design requirements and application needs.

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

INA3221 current and voltage monitor interface for an HC-SR04 ultrasonic sensor, with 5V sensor power routed through a shunt and I2C output to a host MCU.

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.

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.

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

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

This is a LoRa remote control project built around a Raspberry Pi RP2040 SoC and the RFM95W LoRa module. The design includes user interface features such as multiple buttons and LEDs, power management components, and a temperature sensor. The project utilizes SPI, I2C, and USB interfaces for communication and control. #referenceDesign #simple-embedded #raspberrypi #lora #template #reference-design

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #referenceDesign #batterycharger #template #bms #monitor #STC3115 #stm #reference-design #polygon

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm

This project is a Battery Management System (BMS) built around STMicroelectronics' STC3115AIQT battery monitor IC. It uses I2C for communication, features alarm management, and supports battery charging. The power supply, battery connection points, and debug interface are facilitated through connectors. #project #Template #charger #monitor #reusable #module #batterycharger #template #bms #STC3115 #stm