3D Camera Module is a scalable SPI enabled 4 camera array pinout for 3D photogrammetry reconstruction which uses I2C to connect between each module to expand camera capacity while keeping capture sequences in sync. It uses ATMega32U4 with its built in USB 2.0 for data transfer and camera array adjustments and capture as well as a micro SD card slot for local image storage. An interrupt logic pinout should be used on the SPI master module as capture command. Each module is powered via USB-C (5V) or barrel jack (12V regulated to 5V).

sEMG-DAQ is a wearable 6 channel data acquisition unit for capturing surface electromyographic (sEMG) signals from human arm muscles using SJ2-3593D jack connectors while conditioning, digitizing, processing and transmitting them as sEMG data to an external AI accelerated board through an SM12B-SRSS IDC connector where AI models are run for various applications including robotic control, muscle signals medical assessment and gesture recognition. The board leverages an INA125P instrumentation amplifier together with filter stages utilizing LM324QT op-amps for conditioning and an STM32G4A1VET6 microcontroller for the digitization, processing and data transmission of the signals. Since AI models can only be as good as the data, the design of such a DAQ is necessary to ensure clean, reliable and real-time data for AI applications requiring sEMG data. The board also has USB-FS and JTAG to cater for debugging. The power (5V) is fed through a screw terminal and is regulated by two LDK320AM LDO regulators to offer 5V, 3.3V and 1.8V to meet the requirements of various components on the board.

I'm building an audio amplifier. These are the project requirements: - Type of Amplifier: Class D (for energy efficiency). - Input Source: Line-level input from a standard audio source, e.g., mobile phone or PC. - Output Power: 10W per channel (for a stereo setup). - Number of Channels: 2 (stereo output). - Distortion: Total Harmonic Distortion (THD) of less than 0.1% at full power. - Frequency Response: 20Hz to 20kHz. - Power Supply: Operate from a single 12V DC source. - Protection: Over-current and thermal protection for the amplifier IC. - Connectivity: Standard 3.5mm audio jack for input and screw terminals for speaker outputs. - Volume Control: A physical potentiometer for volume control. - Indicator: An LED indicator that shows power ON status. - Size Constraints: PCB size should not exceed 100mm x 100mm. Consider every requirement individually when answering any question

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

This is a class d amplifier with both Bluetooth and Audio Jack connectivity. The power should be a regulated 24 vdc. This project is centralized around the TPA3116D2 class D audio amplifier.

The semgdaq board is a wearable 6 channel data acquisition unit for capturing surface electromyographic (sEMG) signals from human arm muscles using SJ2-3593D jack connectors while conditioning, digitizing, processing and feature extracting them then transmitting the feature data as vectors to an external AI accelerated board through an SM12B-SRSS IDC connector using 12C and UART communication protocals where AI models are run for various applications including robotic control, muscle signals medical assessment and gesture recognition. The feature vectors are comprised of onset detection, slope sign changes, autoregression coefficients and Short Time Fourier Transform magnitude spectrum data for each segment or window of the signals in real time. This vectors can be used as the basis for further feature extraction on more computationally resourceful hardware where machine learning algorthms can be employed for descision making in the applications mentioned earlier. The board leverages INA125P instrumentation amplifiers together with filter stages utilizing LM324QT op-amps for conditioning and an STM32G4A1VET6 microcontroller for the digitization, processing, feature extraction and data transmission. Since AI models can only be as good as the data, the design of such a DAQ is necessary to ensure clean, reliable and real-time data for AI applications requiring sEMG feature data. The board also has USB-FS and JTAG to cater for debugging and external flash memory to extend its data storage and processing capability. The power (5V) is fed through a screw terminal and is regulated by two LDK320AM LDO regulators to offer 5V, 3.3V and 1.8V to meet the requirements of various components on the board.

Power Barrel Connector Jack 2.10mm ID (0.083"), 5.50mm OD (0.217") Through Hole, Right Angle #Barrel_Jack_MountingPin

make this for me now # Device Summary & Specification Sheet ## 1. Overview A rugged, Arduino-Uno-and-Raspberry-Pi-style single-board micro-PC featuring: - Smartphone-class CPU (Snapdragon 990) - USB-C Power Delivery + 4×AA alkaline backup + ambient-light harvester - On-board Arduino-Uno-compatible ATmega328P - External NVMe SSD via USB3 bridge & optional Thunderbolt 3 eGPU support - 5× USB 3.0 ports, HDMI in/out, Gigabit Ethernet & SFP fiber, Wi-Fi, Bluetooth, LoRa - 0.96″ OLED status display, 3.5 mm audio jack with codec --- ## 2. Key Specifications | Category | Specification | |--------------------|-------------------------------------------------------------------------------| | CPU | Snapdragon 990, octa-core up to 2.84 GHz | | Memory | 6 GB LPDDR4x DRAM | | Storage Interface | PCIe Gen3 ×4 → M.2 NVMe + USB 3.1 Gen1 bridge | | MCU | ATmega328P (Arduino-Uno-compatible) | | Power Input | USB-C PD up to 20 V/5 A; 4×AA alkaline backup; ambient-light photodiode boost | | Power Rails | 12 V, 5 V, 3.3 V, 1.8 V, 1.2 V via buck/buck-boost regulators | | USB Hub | 5× USB 3.0 downstream ports | | Display | 0.96″ 128×64 OLED via I²C/SPI | | Networking | 1 × Gigabit RJ45; 1 × SFP fiber; Wi-Fi 802.11ac + Bluetooth; LoRa SX1276 | | Video I/O | HDMI 2.0 input (RX) & output (TX) | | Audio | 3.5 mm jack + TLV320AIC3101 codec; Bluetooth audio | | Form Factor | Raspberry Pi–style header + Arduino-Uno shield headers; 4× standoff mounts | --- ## 3. Complete Parts List | Part | Function | Qty | |------------------------------------------------------------------------------------------------|-----------------------------------------------|-----| | [Snapdragon 990](https://www.flux.ai/search?type=components&q=Snapdragon%20990) | Main application CPU | 1 | | [LPDDR4x DRAM](https://www.flux.ai/search?type=components&q=LPDDR4x%20DRAM) | System memory | 1 | | [eMMC 64GB](https://www.flux.ai/search?type=components&q=eMMC%2064GB) | On-board storage | 1 | | [M.2 NVMe Connector](https://www.flux.ai/search?type=components&q=M.2%20NVMe%20Connector) | External SSD interface | 1 | | [JMS583](https://www.flux.ai/search?type=components&q=JMS583) | PCIe→USB 3.1 bridge for NVMe | 1 | | [Titan Ridge](https://www.flux.ai/search?type=components&q=Titan%20Ridge) | Thunderbolt 3/eGPU controller | 1 | | [STUSB4500](https://www.flux.ai/search?type=components&q=STUSB4500) | USB-C Power-Delivery controller | 1 | | [LTC4412](https://www.flux.ai/search?type=components&q=LTC4412) | Ideal-diode OR-ing | 1 | | [LTC3108](https://www.flux.ai/search?type=components&q=LTC3108) | Ambient-light (solar) energy harvester | 1 | | [Battery Holder 4×AA](https://www.flux.ai/search?type=components&q=Battery%20Holder%204xAA) | Alkaline backup power | 1 | | [TPS53318](https://www.flux.ai/search?type=components&q=TPS53318) | 6 V→5 V synchronous buck regulator | 1 | | [MCP1700-3302E/TO](https://www.flux.ai/search?type=components&q=MCP1700-3302E/TO) | 6 V→3.3 V LDO | 1 | | [TPS63060](https://www.flux.ai/search?type=components&q=TPS63060) | Buck-boost for 12 V rail (eGPU power) | 1 | | [ATmega328P](https://www.flux.ai/search?type=components&q=ATmega328P) | Arduino-Uno microcontroller | 1 | | [ESP32-WROOM-32](https://www.flux.ai/search?type=components&q=ESP32-WROOM-32) | Wi-Fi + Bluetooth co-processor | 1 | | [SX1276](https://www.flux.ai/search?type=components&q=SX1276) | LoRa transceiver | 1 | | [TUSB8041](https://www.flux.ai/search?type=components&q=TUSB8041) | 5-port USB 3.0 hub IC | 1 | | [Ethernet PHY](https://www.flux.ai/search?type=components&q=Ethernet%20PHY) | Gigabit Ethernet physical transceiver | 1 | | [SFP Cage](https://www.flux.ai/search?type=components&q=SFP%20Cage) | Fiber-optic SFP module connector | 1 | | [TDA19978](https://www.flux.ai/search?type=components&q=TDA19978) | HDMI 2.0 receiver (input) | 1 | | [TFP410](https://www.flux.ai/search?type=components&q=TFP410) | HDMI 2.0 transmitter (output) | 1 | | [TLV320AIC3101](https://www.flux.ai/search?type=components&q=TLV320AIC3101) | Audio codec for 3.5 mm jack & Bluetooth audio | 1 | | [Audio Jack 3.5mm](https://www.flux.ai/search?type=components&q=Audio%20Jack%203.5mm) | Headphone/mic port | 1 | | [SSD1306 OLED](https://www.flux.ai/search?type=components&q=SSD1306%20OLED) | Status display | 1 | --- ## 4. High-Level Design & Implementation Steps 1. **Schematic Creation** - Section off blocks: CPU + memory, power-supply, NVMe/USB bridge, MCU, wireless, USB hub, video, audio, I/O headers. - Place all parts from the list and wire per respective datasheet reference circuits. 2. **Power System** - Implement USB-C PD with STUSB4500 → buck/buck-boost & LDO rails. - Add LTC4412 to OR-ing battery pack into 6 V bus. - Include LTC3108 harvest input to 6 V bus (no recharge to AA). - Add decoupling & bulk caps per regulator datasheets; PTC fuses & ESD diodes on inputs. 3. **SoC & High-Speed Interfaces** - Break out Snapdragon 990 BGA with DDR4 routing (point-to-point). - Route PCIe Gen3 lanes to M.2 slot via JMS583 and to Titan Ridge for TB/eGPU. - Follow high-speed layout guidelines: impedance, length matching, EMI filters. 4. **MCU & Expansion Headers** - Place ATmega328P with UNO-style 2.54 mm headers; add ISP 6-pin, I²C pull-ups, reset circuit. 5. **Connectivity Blocks** - USB hub: TUSB8041 + ESD + chokes → five USB-A 3.0 ports. - Ethernet: RJ45 + magnetics + PHY; SFP cage + PHY/SFP interface. - Wireless: ESP32 module pad + SX1276 + antenna matching; program pads. 6. **Video & Audio** - HDMI RX (TDA19978) & TX (TFP410) blocks with TMDS ESD & termination. - Audio codec + 3.5 mm jack; route differential audio lines; add ESD. 7. **Display & Indicators** - SSD1306 OLED on I²C; add pull-ups & backlight power if needed. - LEDs for power, charge, status. 8. **PCB Layout & Mechanical** - Follow Raspberry Pi 2×20 header footprint & UNO shield hole pattern. - Add reinforcement for rugged use; standoffs at corners. - Define 4-layer stackup: • Top: signal • L2: GND • L3: PWR • Bottom: signal 9. **DRC/ERC Reviews** - Run ERC for decoupling, pull-ups, power nets. - Run DRC for high-speed clearance, differential pairs, via aspect ratios. 10. **Fabrication & Testing** - Export Gerbers, IPC-2581, BOM. - Prototype assembly; verify power sequencing, rails, interfaces. - Functional tests: USB-C PD negotiation, NVMe throughput, eGPU over TB3, wireless comm, audio, OLED. --- This spec sheet and part list should guide your Flux schematic and PCB layout workflow through to fabrication and validation. Let me know if you’d like to deep-dive into any specific block or review datasheet details next!

PCB design for Beavis Audio Research's Noisy Cricket Amp. Designed to be an onboard amp for an instrument with a speaker in the body. JFET buffer replaced with op-amp buffer from Jack Orman because JFETs are currently hard to find. LED is dimmer than the original because my eyes are sensitive. ☀️ http://beavisaudio.com/projects/noisycricket/ https://electrosmash.com/noisy-cricket-analysis

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

sEMG prototype

sEMG prototype

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

Microphone module with volume control and 3.5mm jack return and XLR3 output, in progress

Stereo headphone amp meant to fit in a pedal enclosure for use on a pedalboard. Buffers the signal, then splits it to an output meant to go to a mixer and a headphone out. The headphone amp circuit is applied to the signal before the headphone jack. Originally designed to give the ability to run effects after an amp simulator pedal with no effects loop. Example chain: amp sim > wet effects > headphone amp > mixer. References: https://electrosmash.com/images/tech/klon-centaur/klon-centaur-power-supply.png https://aionfx.com/app/files/docs/refractor_documentation.pdf https://www.muzique.com/lab/buffers.htm

This project aims to build an Audio Amplifier using the TDA2822 IC. The TDA2822 is a commonly used dual-channel audio amplifier that can deliver high power output. The amplifier will be designed to drive two speakers with volume control and the audio input can be directly provided through an audio jack. This project is inspired by my class Analogue and Digital electronics.

sEMG-DAQ is a wearable 6 channel data acquisition unit for capturing surface electromyographic (sEMG) signals from human arm muscles using SJ2-3593D jack connectors while conditioning, digitizing, processing and transmitting them as sEMG data to an external AI accelerated board through an SM12B-SRSS IDC connector where AI models are run for various applications including robotic control, muscle signals medical assessment and gesture recognition. The board leverages an INA125P instrumentation amplifier together with filter stages utilizing LM324QT op-amps for conditioning and an STM32G4A1VET6 microcontroller for the digitization, processing and data transmission of the signals. Since AI models can only be as good as the data, the design of such a DAQ is necessary to ensure clean, reliable and real-time data for AI applications requiring sEMG data. The board also has USB-FS and JTAG to cater for debugging. The power (5V) is fed through a screw terminal and is regulated by two LDK320AM LDO regulators to offer 5V, 3.3V and 1.8V to meet the requirements of various components on the board.

The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

3D Camera Module is a scalable SPI enabled 4 camera array pinout for 3D photogrammetry reconstruction which uses I2C to connect between each module to expand camera capacity while keeping capture sequences in sync. It uses ATMega32U4 with its built in USB 2.0 for data transfer and camera array adjustments and capture as well as a micro SD card slot for local image storage. An interrupt logic pinout should be used on the SPI master module as capture command. Each module is powered via USB-C (5V) or barrel jack (12V regulated to 5V).

3D Camera Module is a scalable SPI enabled 4 camera array pinout for 3D photogrammetry reconstruction which uses I2C to connect between each module to expand camera capacity while keeping capture sequences in sync. It uses ATMega32U4 with its built in USB 2.0 for data transfer and camera array adjustments and capture as well as a micro SD card slot for local image storage. An interrupt logic pinout should be used on the SPI master module as capture command. Each module is powered via USB-C (5V) or barrel jack (12V regulated to 5V).

3.5mm switched mono audio jack

sEMG-DAQ is a wearable 6 channel data acquisition unit for capturing surface electromyographic (sEMG) signals from human arm muscles using SJ2-3593D jack connectors while conditioning, digitizing, processing and transmitting them as sEMG data to an external AI accelerated board through an SM12B-SRSS IDC connector where AI models are run for various applications including robotic control, muscle signals medical assessment and gesture recognition. The board leverages an INA125P instrumentation amplifier together with filter stages utilizing LM324QT op-amps for conditioning and an STM32G4A1VET6 microcontroller for the digitization, processing and data transmission of the signals. Since AI models can only be as good as the data, the design of such a DAQ is necessary to ensure clean, reliable and real-time data for AI applications requiring sEMG data. The board also has USB-FS and JTAG to cater for debugging. The power (5V) is fed through a screw terminal and is regulated by two LDK320AM LDO regulators to offer 5V, 3.3V and 1.8V to meet the requirements of various components on the board.

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

Stereo 3‑Band Active Audio Equalizer and Mono Preamplifier using TL072 and LM386 with Right‑Angle PCB‑Edge CUI SJ1‑3535NG TRS Jacks for Jack Sensing and Routing

TECHNICAL ASSIGNMENT AND DESIGN GUIDE Active Three-Way Crossover on NE5532 Powered by AM4T-4815DZ and Amplifiers TPA3255 (Updated Version) 1. GENERAL PURPOSE OF THE DEVICE The goal of the development is to create an active three-way audio crossover for one channel of a loudspeaker system, working with the following drivers: LF: VISATON W250 MF: VISATON MR130 HF: Morel MDT-12 Each frequency range is amplified by a separate power amplifier: LF: TPA3255 in PBTL mode (mono) MF + HF: second TPA3255 in stereo mode (one channel for MF, the other for HF) The crossover accepts a single linear audio signal (mono) and divides it into three frequency bands: Range Frequency Range LF 0 – 650 Hz MF 650 – 2500 Hz HF 2500 Hz and above Filter type: Linkwitz–Riley 4th order (24 dB/oct) at each crossover point (650 Hz and 2500 Hz). The crossover must provide: minimal self-noise; no audible distortion in the audible range; stable operation with NE5532 at ±15 V power supply; easy adjustment of the level for each band, as well as the overall level (via the input buffer). 2. FILTER TYPES AND BASIC OPERATING PRINCIPLES Each filter is implemented as two cascaded Sallen–Key 2nd order (Butterworth) stages, resulting in a final 4th order LR4 filter. Topology: non-inverting Sallen–Key, optimal for NE5532. For all stages: Cascade gain: K ≈ 1.586 This provides a Q factor of 0.707 (Butterworth), which in combination gives a Linkwitz–Riley 4th order. 3. COMPONENT VALUES FOR FILTERS 3.1 Universal Parameters RC chain capacitors: 10 nF, film capacitors, tolerance ≤ 5% Resistors: metal-film, tolerance ≤ 1% The gain of each stage is set by feedback resistors: Rf = 5.9 kΩ Rg = 10 kΩ K ≈ 1 + (Rf / Rg) ≈ 1.59 The circuit should allow for the installation of a small capacitor (10–47 pF) in parallel with Rf (footprint provided) for possible stability correction (not mandatory to install in the first revision). 3.2 650 Hz Filters (Low-frequency boundary for MF) These are used for the division between W250 and MR130. LP650 — Low-frequency Filter 2nd Order R1 = 24.9 kΩ R2 = 24.9 kΩ C1 = 10 nF C2 = 10 nF Two stages: LP650 #1 and LP650 #2. HP650 — MF High-frequency Filter 2nd Order Same values: R1 = 24.9 kΩ R2 = 24.9 kΩ C1 = 10 nF C2 = 10 nF Two stages: HP650 #1 and HP650 #2. 3.3 2500 Hz Filters (Upper boundary for MF) These are used for the division between MR130 → MDT-12. LP2500 — High-pass MF Filter R1 = 6.34 kΩ R2 = 6.34 kΩ C1 = 10 nF C2 = 10 nF Two stages: LP2500 #1 and LP2500 #2. HP2500 — High-frequency Filter Same values: R1 = 6.34 kΩ R2 = 6.34 kΩ C1 = 10 nF C2 = 10 nF Two stages: HP2500 #1 and HP2500 #2. 4. OPERATIONAL AMPLIFIERS The NE5532 (dual op-amp, DIP-8 or SOIC-8) is used. A minimum of 4 packages (8 channels) for filters: NE5532 Function U1A, U1B LP650 #1, LP650 #2 (LF) U2A, U2B HP650 #1, HP650 #2 (Lower MF cut-off) U3A, U3B LP2500 #1, LP2500 #2 (Upper MF cut-off) U4A, U4B HP2500 #1, HP2500 #2 (HF) Additionally: U5 — input buffer / preamplifier (both channels) If necessary, an additional NE5532 (U6) for the balanced input (see section 6.2). All NE5532 should have local decoupling for power supply (see section 5.1). 5. CROSSOVER POWER SUPPLY AM4T-4815DZ DC/DC module is used: Input: 36–72 V, connected to the 48 V power supply for TPA3255 amplifiers. Output: +15 V / –15 V, up to 0.133 A per side. Maximum output capacitance: ≤ 47 µF per side (according to the datasheet). 5.1 Power Filtering Input (48 V): RC variant (simpler, acceptable for the first revision): R = 1–2 Ω / 1–2 W C = 47–100 µF (for 63 V or higher) LC variant (preferred for improved noise immunity): L = 10–22 µH C = 47–100 µF The developer may implement LC if confident in choosing the inductance and its parameters. Output +15 V and –15 V (general filtering): Electrolytic capacitor 10–22 µF per side 100 nF (X7R) per side to GND Local decoupling for NE5532 (REQUIRED): For each NE5532 package: 100 nF between +15 V and GND 100 nF between –15 V and GND Place as close as possible to the op-amp power pins (short traces). Additional local filtering for power lines: For each NE5532, decouple from the ±15 V main rails: Either 4.7–10 Ω resistor in series with +15 V and –15 V, Or ferrite bead in each rail. After this component, place local capacitors (100 nF + 1–4.7 µF) to ground. 6. INPUT TRACT: INPUTS, BUFFER, ADJUSTMENT 6.1 Unbalanced Input (RCA / Jack / Linear) The main mode is the unbalanced linear input, for example, RCA. Input tract structure: RF-filter and protection: Signal → series resistor Rin_series = 100–220 Ω After resistor — capacitor Cin_RF = 470–1000 pF to GND This forms a low-level RF filter and reduces high-frequency noise. DC-block (low-pass HP-filter): Capacitor Cin_DC = 2.2–4.7 µF film in series Resistor to ground Rin_to_GND = 47–100 kΩ Cut-off frequency — negligible in the audio range but removes DC. Input buffer / preamplifier (NE5532, U5): Non-inverting configuration. Input — after DC-block. Gain: adjustable, e.g., Rg_fixed = 10 kΩ (to GND through trimmer) Rf = 10–20 kΩ + footprint for trimmer (e.g., 20 kΩ) The gain should be in the range of 0 dB to +10…+12 dB. Possible configuration: Rg = 10 kΩ fixed Rf = 10 kΩ + 10 kΩ trimmer in series. This allows adjusting the overall level of the crossover according to the source and amplifier levels. Buffer output: A low-impedance output (after NE5532) This signal is simultaneously fed to the inputs of all filters: LP650 (LF) HP650 → LP2500 (MF) HP2500 (HF) 6.2 Balanced Input (XLR / TRS) — Optional, but laid out on the board The board should allow for a balanced input, even if it’s not used in the first revision. Implementation requirements: XLR/TRS connector (L, R, GND) or separate 3-pin header. Simple differential receiver on NE5532 (extra U6 package or use one channel of U5 if sufficient). Circuit: classic instrumentation amplifier or differential amplifier: Inputs: IN+ and IN– Output — single-ended signal of the same level (or slightly amplified), fed to DC-block and buffer (or directly to the buffer if integrated). Switching between balanced/unbalanced mode: Implement using jumpers / bridges or adapters: Either switch before the buffer, Or use two separate pads, one of which is unused. All balanced input grounds must be connected to the same AGND point as the unbalanced input to avoid ground loops. 7. LEVEL ADJUSTMENT OF BANDS (BEST METHOD) The level adjustment of each band (LOW, MID, HIGH) is required to match the sensitivity of the speakers and amplifiers. Recommended method: After each full filter (after LP650×2, MID-chain HP650×2 → LP2500×2, HP2500×2), install: A passive attenuator: Series: Rseries (0–10 kΩ, adjustable) Shunt: Rshunt to GND (10–22 kΩ, fixed or adjustable) For simplicity and reliability: Implementation on the board: For each band (LOW, MID, HIGH) provide: Pad for multi-turn trimmer 10–20 kΩ as a divider (between signal and ground) in the "level adjustment" configuration. If adjustment is not needed — install a fixed divider (two resistors) or simply use a jumper. It is preferable to use: For setup: multi-turn trimmers 10–20 kΩ, available on the top side of the board. Nominals for the initial configuration can be selected through measurements, but the PCB should have flexibility. This provides: Accurate balancing of band volumes without interfering with the filters; Flexibility for fine-tuning to the specific characteristics of the speakers. 8. INPUTS AND OUTPUTS OF THE CROSSOVER (FINAL) 8.1 Inputs 1× Unbalanced linear input (RCA or 3-pin header) 1× Balanced input (XLR/TRS or 3-pin header) — optional, but space must be provided on the board. Input impedance (unbalanced after RF-filter): 22–50 kΩ. The input tract must be implemented using shielded cables. 8.2 Outputs Outputs to amplifiers: Output Signal LOW OUT After LP650×2 (LF) MID OUT After HP650×2 → LP2500×2 (MF) HIGH OUT After HP2500×2 (HF) Each output: Series resistor 100–220 Ω (prevents possible oscillations and simplifies cable management). A nearby own AGND pad (ground output), so the signal pair SIG+GND runs together. Outputs should be compactly placed on 2-pin connectors (SIG+GND) or 3-pin (SIG+GND+reserve). 9. PCB DESIGN REQUIREMENTS 9.1 Board Number of layers: 2 layers Bottom layer: solid analog ground (AGND). 9.2 Component Placement Key principles: RC chains of each filter (R1, R2, C1, C2, Rf, Rg) should form a compact "island" around the corresponding op-amp. If elements are placed too far apart, the filter will not work correctly (calculated frequency and Q will shift). Feedback tracks (Rf and Rg) should be as short and direct as possible. The AM4T-4815DZ module should be placed: Far from the input buffer, Far from the first filter stages, If necessary, make a "cutout" in the ground under it to limit noise propagation. Place the input connector, RF-filter, and buffer on one side of the board, and the output connectors on the opposite side. 9.3 Ground The entire audio circuit uses one analog ground: AGND. Connect AGND to the power ground (48 V and amplifiers) at one point ("star"). The star should be implemented as: One point/pad where: The ground of the input, The ground of the filters, The ground of the outputs, The ground of the DC/DC. Avoid long narrow "ground" jumpers — use wide polygons with a single connection point. 9.4 Placement of Output Connectors Group LOW/MID/HIGH compactly. Each should have its own GND pad nearby. Route the SIG+GND pairs as signal pairs, avoiding large loops. 10. ADDITIONAL ELEMENTS: PROTECTION, TEST POINTS 10.1 Test Points (TP) Be sure to provide test points (pads): TP_IN — crossover input (after buffer) TP_LOW — LF filter output TP_MID — MF filter output TP_HIGH — HF filter output TP_+15, TP_–15, TP_GND — power control This greatly simplifies debugging with an oscilloscope. 10.2 Power Protection On the 48 V input — it is advisable to provide: Diode/scheme for reverse polarity protection (if possible), TVS diode or varistor for voltage spikes (optional). 10.3 Possible Stability Correction Pads for small capacitors (10–47 pF) in parallel with Rf in buffers and, if necessary, in some stages — in case of stability issues (this can be not installed in the first revision, but footprints should be provided). 11. BILL OF MATERIALS (BOM) Operational Amplifiers: NE5532 — 4 pcs (filters) NE5532 — 1–2 pcs (input buffer and balanced input) Total: 5–6 NE5532 packages. Resistors (1%, metal-film): 24.9 kΩ — 8 pcs 6.34 kΩ — 8 pcs 10 kΩ — ≥ 12 pcs (feedback, buffers, etc.) 5.9 kΩ — 8 pcs 22 kΩ — 1–2 pcs (input, auxiliary chains) 47–100 kΩ — several pcs (DC-block, input) 100 kΩ — 1 pc (if needed) 100–220 Ω — 4–6 pcs (outputs, RF, protection) 4.7–10 Ω — 2 pcs for each op-amp or group of op-amps (power filtering) — quantity to be clarified during routing. Trimmer Resistors: 10–20 kΩ multi-turn — one for each band (LOW, MID, HIGH) 10–20 kΩ — 1–2 pcs for the input buffer (overall gain adjustment). Capacitors: 10 nF film — 16 pcs (RC filters) 2.2–4.7 µF film — 1–2 pcs (input DC-block) 10–22 µF electrolytic — 2–4 pcs (DC/DC outputs) 1–4.7 µF (X7R / tantalum) — 1 pc for local power filtering (optional). 100 nF ceramic X7R — 10–20 pcs (local decoupling for each op-amp) 470–1000 pF — 1–2 pcs (RF filter on the input) 10–47 pF — optional for stability correction (Rf). Power Supply: AM4T-4815DZ — 1 pc Inductor 10–22 µH (if LC filter) — 1 pc R 1–2 Ω / 1–2 W — 1 pc (if RC filter). Connectors: Input (RCA + 3-pin for internal input) Balanced (XLR/TRS or 3-pin header) Outputs LOW/MID/HIGH — 2-pin/3-pin connectors. 12. TESTING RECOMMENDATIONS 12.1 First Power-up Apply ±15 V without installed op-amps. Check with a multimeter: +15 V –15 V No short circuits in the power supply. Install the op-amps (NE5532). Apply a sine wave of 100–200 mV RMS (signal generator). Check with an oscilloscope at TP: LP650 — should pass LF and roll off everything above 650 Hz. HP650 — should roll off LF, pass everything above 650 Hz. LP2500 — should roll off above 2500 Hz. **HP250 0** — should pass everything above 2500 Hz. 12.2 Phase Check The Linkwitz–Riley 4th order should give a flat frequency response when summed at the crossover points. This can be verified with REW/Arta. 12.3 Noise Check If there is noticeable "shshsh" or whistling: Check: Grounding layout (star) Placement and filtering of AM4T-4815DZ Presence and proper installation of all 100 nF and local filters. 13. FINAL RECOMMENDATIONS FOR BEGINNERS Do not rush, build the circuit step by step: input → buffer → one filter → test, then continue. Check component values at least twice before soldering. Filters should be routed as compact "islands" around the op-amp, do not stretch R and C across the board. Always remember the rule: "The feedback trace should be as short as physically possible." Before ordering the PCB, make a "paper prototype": print at 1:1, cut it out, place real components to check everything fits.

WiFi/BLE Smart Humidity Sensor with ESP32 and SHT31-DIS-B, Powered by 5V Barrel Jack

preamplificador de audio para microfono jack 5.0 , con entrada de voltage simple 9 voltios

Project Title: Plant Monitoring and Irrigation System Overview: This system is based on the ESP32-S3 and is designed to manage irrigation for a multi-floor building. Key Features: Multi-Floor Operation: The system controls three separate floors. Each floor's irrigation can be managed independently. Irrigation and Pump Control: Each floor uses a solenoid valve to regulate water flow. The solenoid valves are operated via MOSFETs. A relay engages an AC water pump when a MOSFET triggers a solenoid valve. Hardware Interconnects: Screw Terminal connectors are added for connecting the solenoid valves and the motor pump. A DC Jack is included to supply power to the system. User Interface & Connectivity: Two JST connectors are provided for integrating an OLED display, a rotary encoder, and a pushbutton. Future enhancements may include the addition of soil moisture sensors. Remote Control: The system is designed for future integration with Blynk IoT. Blynk IoT will offer both manual control and timer-based irrigation modes for each floor.

This project involves designing a complete schematic for a robotic arm controller based on the ESP32-C3 microcontroller, specifically using the ESP32-C3-MINI-1-N4 module. The design features a dual power input system and comprehensive power management, motor control, I/O interfaces, and status indicators—all implemented on a 2-layer PCB. Key Specifications: Microcontroller: • ESP32-C3-MINI-1-N4 module operating at 3.3V. • Integrated USB programming connections with reset and boot mode buttons. Power System: • Dual power inputs with automatic source selection: USB-C port (5V input) and barrel jack (6-12V input). • Power management using LM74610 smart diode controllers for power source OR-ing. • AMS1117-3.3 voltage regulator to deliver a stable 3.3V supply to the microcontroller. • Filter capacitors (10μF electrolytic and 100nF ceramic) at the input and output of the regulators. • Protection features including USBLC6-2SC6 for USB ESD protection and TVS diodes for barrel jack overvoltage protection. Motor Control: • Incorporates an Omron G5LE relay with a PC817 optocoupler and BC547 transistor driver. • Provides dedicated header pins for servo motors with PWM outputs. • Flyback diode protection implemented for relay safety. I/O Connections: • Header pins exposing ESP32-C3 GPIOs: Digital I/O (IO0-IO10, IO18, IO19) and serial communication lines (TXD0, RXD0), plus an enable pin. • Each I/O pin includes appropriate 10kΩ pull-up/pull-down resistors to ensure reliable performance. Status Indicators: • A power status LED with a current-limiting resistor. • A user-controllable LED connected to one of the GPIO pins. PCB Layout Requirements: • 2-layer PCB design with separate ground planes for digital and power sections. • Placement of decoupling capacitors close to power pins to reduce noise. • Adequate trace width for power lines to ensure efficient current flow. • Inclusion of mounting holes at the board corners for secure installation. • All components are properly labeled with correct values for resistors, capacitors, and other passive elements, following standard design practices for noise reduction, stability, and reliability. #RoboticArmController #ESP32C3 #SchematicDesign #PCBDesign #ElectronicsDesign #PowerManagement #MotorControl #EmbeddedSystems #IoT

Interface for Wemos D1 mini to sct-013 current sensor via a 3.5mm jack

Boost circuit based on the Son of Screamer by Jack Orman. Less distortion, more volume, gain minimized. Power supply not included; meant to be combined with Beloved to make OD/boost circuit.

The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

3D Camera Module is a scalable SPI enabled 4 camera array pinout for 3D photogrammetry reconstruction which uses I2C to connect between each module to expand camera capacity while keeping capture sequences in sync. It uses ATMega32U4 with its built in USB 2.0 for data transfer and camera array adjustments and capture as well as a micro SD card slot for local image storage. An interrupt logic pinout should be used on the SPI master module as capture command. Each module is powered via USB-C (5V) or barrel jack (12V regulated to 5V).

Stereo audio jack

Power Barrel Connector Jack 2.10mm ID (0.083"), 5.50mm OD (0.217") Through Hole #commonpartslibrary #connector #barrel #jack #Power-Connector #PJ-044

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply (including LED), a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. #template

Guitar pedal starter template based on project by Mark Wu. Includes schematic and PCB layout for basic DIY pedal hardware. This includes two 1/4" jacks (one for input and one for output), a 9V power supply, a 3PDT true bypass wiring setup, and an example potentiometer that can be copy/pasted throughout the circuit. size is a good default size for a 125B enclosure. The headers are meant to be unpopulated so that wires can be soldered to the pads. PCB design rules imported from the JLCPCB 2-layer stackup template. Meant to be used with the 3PDT Breakout Board on my profile. #template