This design implements a USB security token powered by an STM32 microcontroller. The device is engineered for compactness and efficient PCB integration while ensuring robust security features. Key elements of the design include: - **Microcontroller Core:** A STM32F103T8U6 serves as the primary processing unit, handling USB communication and security protocols. - **USB Interface:** A USB-A plug provides connectivity to the host. Dedicated net portals ensure proper routing of the VBUS, D+, D–, and ground signals. - **Power Regulation:** A low-dropout regulator supplies a stable 3.3V operating voltage, ensuring low noise and proper current supply to the microcontroller and peripherals. - **Signal Conditioning and EMI Filtering:** An EMI filter is used to maintain signal integrity and reduce interference while preserving the security token’s functionality. - **Synchronous Elements:** A ceramic resonator is incorporated to provide a precise clock source for USB data transfer and microcontroller operations. - **Additional Components:** Surface-mount resistors, capacitors, and LED indicators are deployed to ensure proper conditioning, decoupling, and status feedback. Their compact 0402 packages facilitate a highly integrated design. - **Connectivity and Net Portals:** Custom net portals are used throughout the schematic to streamline connectivity and PCB layout, keeping the design modular and easy to modify. This USB security token is designed with industry-standard components and robust connectivity to ensure secure, reliable operation in portable security applications. #USBToken #STM32 #PCBDesign #SecurityTechnology #PortableSecurity #Microcontrollers #USBInterface #PowerRegulation #EMIProtection #CompactDesign

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

This project is a Signal Generator, designed to output waveforms such as sine, square and triangular waves. It leverages the capabilities of operational amplifiers (op-amps) like the LMV321 in combination with resistors and capacitors to shape the output signals. The design benefits from the op-amps' negative feedback to stabilize and regulate the signal output. #project #LMV321

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

This is a BLE remote control Reference Design. It features a Microchip RN4871U BLE module for communication, various push buttons (Up, Down, Left, Right, OK) for control input, and a piezoelectric buzzer for audio feedback. Power is supplied by a battery and it is regulated to 3.3V for the BLE module. #BLE #IoT #referenceDesign #simple-embedded #microchip #template #reference-design

This is a BLE remote control Reference Design. It features a Microchip RN4871U BLE module for communication, various push buttons (Up, Down, Left, Right, OK) for control input, and a piezoelectric buzzer for audio feedback. Power is supplied by a battery and it is regulated to 3.3V for the BLE module. #BLE #IoT #referenceDesign #simple-embedded #microchip #template #reference-design

A compact battery-powered door/window sensor built around the ESP32-C3-MINI-1-N4 module. The design uses a single non-rechargeable AA cell with a TPS613221A 3.3 V boost regulator, reed switch magnetic contact sensing, low-power wake/report/sleep firmware strategy, RGB status LED for setup feedback, BOOT/EN controls, programming header, and input polarity protection. It is intended for smart-home security and automation applications, supporting WiFi or Bluetooth LE hub reporting with emphasis on low idle current, reliable RF burst power delivery, and field-replaceable battery operation. #ESP32-C3 #BLE #WiFi #DoorSensor #WindowSensor #ReedSwitch #LowPower #BatteryPowered #SmartHome #IoT

FEEDBACK PROJECT - Change History broke the project - Converts the 5v power from microUSB to 3.3v.

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

Arduino-compatible SMC3/SimTools 3-DOF motion controller for three 12 V worm-drive motors, Hall feedback sensors, dual USB-C interfaces, and E-stop safety input.

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This project is a distance detecting sensor circuit build around GP2Y0D805Z0F IC from SHARP/Socle Technology. It includes decoupling capacitors, feedback resistors, and a LED for signal indication, with power being supplied via the J1 connector. #referenceDesign #industrialsensing #sharp #template #reference-design

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This project is a distance detecting sensor circuit build around GP2Y0D805Z0F IC from SHARP/Socle Technology. It includes decoupling capacitors, feedback resistors, and a LED for signal indication, with power being supplied via the J1 connector. #referenceDesign #industrialsensing #sharp #template #reference-design

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

This project is a Bluetooth-controlled smart mirror design. It uses an ESP32-MINI-1 for Bluetooth connectivity, an MPU-6050 IC sensor for gesture control, and a RGB LED for visual feedback. The design also comprises of other components like capacitors, resistors, and a USB-C connector for power. #referenceDesign #edge-computing #edgeComputing #template #reference-design #reusable #module #edge-computing #edgeComputing #sublayout #esp32 #lazer #sensor

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

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

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

NOTICE: This board has a incorrectly sized battery holder. If building this revision, also build the [adaptor board](flux.ai/markwuflux/adaptor-board-for-universal-electronic-derailleur-v1) Cable Index Shifting Electronic Derailleur. The first version just uses a linear actuator because I suck at ME design. I imagine it would be pretty easy to build a reeling one with positional feedback.

This project involves the design and implementation of a motor control circuit using an L298N motor driver IC and a Seeed Studio XIAO ESP32S3-Sense microcontroller. The motor driver operates a single DC motor ($M1$) with control signals provided by the microcontroller. Additionally, the project includes a WS2812B-B addressable RGB LED, enabling visual feedback or status indication. Primary goals: - Control the speed and direction of the DC motor using the ESP32S3 microcontroller. - Provide status indication via the RGB LED.

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This project is a Oscillator Circuits, designed to output waveforms such as sine, square and triangular waves. It leverages the capabilities of operational amplifiers (op-amps) like the LMV321 in combination with resistors and capacitors to shape the output signals. The design benefits from the op-amps' negative feedback to stabilize and regulate the signal output. #project #LMV321 #Oscillator #waveforms

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

The VLV041235L-L20 rectangular, Z-axis LRA can be used for a variety of haptic feedback applications. This LRA is different than most rectangular LRA's which oscillate in the X plane, along the length of the device. Like all LRA's this device is typically connected to a LRA driver IC which produces the AC drive signal for this device.

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

Rigid-flex smart ring for Islamic prayer companion use, with compact BLE SoC, capacitive swipe electrodes, haptic feedback, rechargeable battery power, and body-worn BLE antenna constraints.

Compact no-test-point relayout of the EVAL-LTM4712-A2Z regulator circuit, optimized for small form factor with selectable/replaceable feedback resistor values for 12 V to 13 V output operation.

> ESP32-based multi-channel audio and haptic control system powered by an external 12 V input, engineered to drive 8 vibrotactile outputs and 2 speaker channels. The design includes integrated thermal monitoring and offers optional support for AUX and microSD audio sources, ensuring flexible multimedia and feedback applications in a compact, efficient platform.

300 W universal-input isolated offline SMPS based on a modified ATX-style architecture. Universal 115-230 VAC, 50/60 Hz input via fused IEC C14 inlet. Outputs: +12 V at 20 A, +5 V at 14 A, +3.3 V at 12 A, +5 Vsb at 2.5 A, and -12 V at 0.3 A. Includes primary rectification with GBU806 bridge, bulk capacitors, bleeders, snubbers, main PWM and driver transformer, standby flyback, optocoupler and TL431 feedback, supervisor logic, test points, fan and heatsink provisions, and 2-layer FR-4 PCB layout with 8 mm primary-secondary isolation and heavy copper routing on high-current rails.

4×4 cm USB-C PD & Qi Wireless Power Bank with Li-Po Charging, Power-Path Management, 3.3 V LDO, Full-Bridge Gate Driver, LED Resistors, and Corrected 5 V Output Feedback (Schematic Cleaned: Redundant Net Portals/Passives Removed, Fuel-Gauge LED Channels Verified, ERC/DRC Issues Resolved)

Smart fan sequencer for PCs, servers, AV racks, and 3D printers: staggers 12V PWM fans with RPM feedback via I2C, reducing inrush and noise

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.

ATmega328P Dual Sabertooth Motor Controller Interface with Encoder Feedback and Protected 5V Input (KiCad 9, Compact Design)

Smart Garden Watering System – Overview The Smart Garden Watering System is an automated irrigation controller designed to intelligently water plants based on user-set schedules and real-time water level feedback. It is ideal for home gardens, indoor plants, or small-scale agricultural settings. This system helps conserve water, reduce manual lobar, and ensure healthy plant growth.

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

This project is a distance detecting sensor circuit build around GP2Y0D805Z0F IC from SHARP/Socle Technology. It includes decoupling capacitors, feedback resistors, and a LED for signal indication, with power being supplied via the J1 connector. #referenceDesign #industrialsensing #sharp #template #reference-design

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

Device embedded with sensors and actuators, capable of monitoring stress levels and providing personalized feedback to help users manage stress effectively. The device will be made from smart fabric integrated with sensors to detect physiological signals associated with stress. It will provide real-time feedback through haptic or visual cues to guide users in practicing relaxation techniques

+12V ---- VCC (TL494) GND ---- GND (TL494) |---- RT (10kΩ) |---- CT (0.01uF) CT --| | OSC OUT ---------- DTC ---------- GND (conectar a tierra) FEEDBACK ---|--(Divisor Resistor o Capacitor) | |--------------(Entrada de Audio) OUT_A ------------- GATE Q1 (IRF540N) OUT_B ------------- GATE Q2 (IRF540N) Q1 (D) --- L ------------------- Speaker Q2 (D) --- GND Capacitor de acoplamiento y desacoplamiento

This is a smart blind control system reference design designed to automate the operation of window blinds. It utilizes an ESP32 microcontroller for managing control signals and an A4988 stepper motor driver to control blinds' movement. It also includes USB interfacing and LED feedback. #referenceDesign #edge-computing #edgeComputing #espressif #template #blind #DC #motor #servo #esp32 #reference-design

Arduino Uno shield used to monitor chimney smoke and provide feedback to stove. This shield powers the Arduino using TEGs and a battery. This shield provides power to an LED, fans, and a light sensor used to detect light intensity.

This project is a Oscillator Circuits, designed to output waveforms such as sine, square and triangular waves. It leverages the capabilities of operational amplifiers (op-amps) like the LMV321 in combination with resistors and capacitors to shape the output signals. The design benefits from the op-amps' negative feedback to stabilize and regulate the signal output. #project #LMV321 #Oscillator #waveforms

Cable Index Shifting Electronic Derailleur. The first version just uses a linear actuator because I suck at ME design. I imagine it would be pretty easy to build a reeling one with positional feedback.