This module involves the design of a keypad lock system. It utilizes an ATMEGA328P microcontroller, buzzers, LEDs for indicator functions and a 4x3 matrix keypad. An in-circuit serial programming (ISP) header is also present for programming the microcontroller. #template #lock #keypad #reusable #module #simple-embedded #microchip #arduino #atmega328 #TPS613222A #ISP #buzzer #sublayout

Connector Header Surface Mount 2 position 0.049" (1.25mm)

Connector Header Surface Mount 2 position 0.049" (1.25mm)

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #attiny2313 #TPS613222A #ISP #buzzer #reusable #module #simple-embedded #microchip #arduino #sublayout

Through hole straight pin header, 1x04, 4 pin, 4-pin, horizontal, angled, 2.54mm pitch, 6mm pin lenght single row

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #arduino #attiny2313 #TPS613222A #ISP #buzzer #referenceDesign #simple-embedded #microchip #template #reference-design

An I2C extension shield with 6 shielded ethernet ports and a TCA9548 breakout board. This board is for the target side, any microcontroller with a standard Arduino header can use it. With proper target side hardware and an SSTP ethernet cable, the board provides robust i2c communication over 10ft(could be longer, haven't tested it yet) with a bitrate of 400kHz under a noisy environment( near motors, power cables, switches, etc). The shield board provides power to the target side and can power the i2c device. The board also supports drdy trigger, which is available on many i2c sensors. The TCA9548 breakout board is for a scenario in which all of your i2c devices have the same address. #Arduino #Uno #Shield #Template #project-template #project

Important Note: You must connect your own SPI/ICSP programming header if you want to burn the Arduino bootloader to the MCU. SMD Manufacturing: Need a hotplate and solderpaste Good to haves: - Oscillator Decoupling Caps Expose UART via connector Programming Button Onboard LED Reset Button You don't have to populate everything! Only these are mandatory: Reset Button Find the reference schematic here: https://www.arduino.cc/en/uploads/Main/ArduinoNano30Schematic.pdf

Connector Header Through Hole 2 position 0.079" (2.00mm) 01x02 JST B2B PH K

System Architecture Overview with PWM Interface, Power Stage, Protections, EMI Filters, Connectors, Hall-Effect Current Monitoring, 4-pin JST-XH Control Header, Isolation & Default-OFF PWM Behavior, Compact Mechanical Layout #hall-sensing #isolated-control #compact-layout

ESP32-DevKitC Minimal 2-Layer Carrier with Edge USB/JTAG, CAN 1x4 Header, Status LEDs, and Bring-Up Pads

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.

Pi Zero 2 W Power HAT – 6 V Input, 5.2 V Buck to Pi 5 V Header via 1.85 A Fuse, Enhanced Input & Pi Rail Protection (TVS + High-Hold PTC + 5 A Schottky)

Ultra-Compact 2-Layer ESP32-C3 Control PCB for BCOTI V2_Beta with USB-C Power, USB-A Data, CV256 Mini2, LZE039, Button Header, and Pot-Based Brightness Control

IR Sensor Header Integration and Modular Sensor System

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

Through Hole straight pin header, 01x07, 2.54mm pitch, single row #connector #pinheader #tht

Simple inline 2 pin header analog filter using common 603 sized components

The Micro is a microcontroller board based on the ATmega32U4 (datasheet), developed in conjunction with Adafruit. It has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a micro USB cable to get started. It has a form factor that enables it to be easily placed on a breadboard. The Micro board is similar to the Arduino Leonardo in that the ATmega32U4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Micro to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.

This is an office productivity hub featuring an STM32F103C8T6 MCU, GC9A01A display driver, voltage regulator, capacitors, resistors, switches, USB-C, and SWD header. #referenceDesign #edge-computing #edgeComputing #stm #template #iot #stm32f1 #reference-design

This module involves the design of a keypad lock system. It utilizes an ATMEGA328P microcontroller, buzzers, LEDs for indicator functions and a 4x3 matrix keypad. An in-circuit serial programming (ISP) header is also present for programming the microcontroller. #template #lock #keypad #reusable #module #simple-embedded #microchip #arduino #atmega328 #TPS613222A #ISP #buzzer #sublayout

This module involves the design of a keypad lock system. It utilizes an ATMEGA328P microcontroller, buzzers, LEDs for indicator functions and a 4x3 matrix keypad. An in-circuit serial programming (ISP) header is also present for programming the microcontroller. #template #lock #keypad #reusable #module #simple-embedded #microchip #arduino #atmega328 #TPS613222A #ISP #buzzer #sublayout

This module involves the design of a keypad lock system. It utilizes an ATMEGA328P microcontroller, buzzers, LEDs for indicator functions and a 4x3 matrix keypad. An in-circuit serial programming (ISP) header is also present for programming the microcontroller. #template #lock #keypad #reusable #module #simple-embedded #microchip #arduino #atmega328 #TPS613222A #ISP #buzzer #sublayout

Elementos necesarios en Proteus 8 Busca estos componentes en la biblioteca (modo "Pick Devices"): Conector J1772 – usa un conector genérico de 4 pines (como HEADER 4 o un DB9 si necesitas algo similar). Resistencias: R1: 150 Ω R2: 330 Ω R3: 150 Ω R4: 2.7 Ω Interruptor SPST o jumper simulando "Punto A", "Punto B" y "GND". Fuente de alimentación de 5V para simular BAT1. Ground (GND) para las conexiones a tierra. Batería (Battery) de 5V (puede ser una batería o una carga equivalente en Proteus). Indicador LED (opcional) si quieres ver visualmente la salida de carga o conexión. 🛠️ Pasos para construir el circuito Sección del conector (lado izquierdo) Coloca un conector de 4 pines y nómbralo "J1772". Conecta el primer pin a una fuente de 5V opcional (simulando señal de control). Añade las resistencias R1 (150Ω) y R2 (330Ω) en serie, con un nodo medio hacia “Punto A”. Conecta el otro lado de R1 a "Punto B". Conecta el otro extremo de R2 a tierra. Agrega interruptores SPST para "Punto A", "Punto B" y "GND" para simular las uniones cuando se conectan al cargador. Sección de carga (lado derecho) Coloca las resistencias R3 (150Ω) y R4 (2.7Ω) tal como en la imagen, entre el conector y la batería. Coloca una batería (BAT1) de 5V, y conecta el negativo a tierra. Asegúrate de cerrar correctamente los interruptores (simulando conexión). 🔄 Simulación Usa "Interactive Simulation" en Proteus. Agrega etiquetas como "PUNTO A", "PUNTO B", etc., si deseas facilitar el seguimiento. Observa cómo el voltaje pasa a través de las resistencias y carga la batería. Puedes usar voltímetros o osciloscopios virtuales para observar los cambios de voltaje y corriente. ✅ Consejos finales Si no encuentras la resistencia exacta de 2.7Ω, puedes colocar una personalizada. Puedes usar Virtual Terminal si quieres simular señales de comunicación en el conector. El conmutador central (como se muestra en la línea de puntos) puede implementarse con switches DPDT o nodos que conectes manualmente en la simulación.

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #attiny2313 #TPS613222A #ISP #buzzer #reusable #module #simple-embedded #microchip #arduino #sublayout