Project Brainstorming Guide

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0:59

Below is the updated schematic plan that incorporates all the necessary parts. You can click “Apply changes” in Flux to update your project with these components and wiring instructions:
Updated Schematic Plan
  1. ESP32 Module & I²C Expanders:
    • ESP32 Module:
      • U1: Use your existing ESP32-WROOM-32D.
      • Verify that its power pins are connected to the 5V rail and its ground is tied to the common ground.
    • MCP23017 Expanders:
      • Add four additional SMD MCP23017-E/SP chips, so you have a total of five.
      • Set their address pins (A0, A1, A2) to assign unique I²C addresses (e.g., 0x20–0x24).
      • Place a 0.1 µF decoupling capacitor between VDD and GND for each expander.
  2. USB Programming & microSD Interfaces:
    • USB Interface:
      • Include an SMD USB-to-UART bridge (such as CP2102 or CH340) with its necessary support circuitry.
      • Route its TX/RX lines to the ESP32’s RX/TX pins.
      • Connect the DTR/RTS lines of the bridge to the ESP32’s EN (reset) and IO0 (boot) pins so that auto-program mode is supported.
      • Add a mini-USB or micro-USB connector on the PCB labeled “USB PROG”.
    • MicroSD Interface:
      • Confirm that the existing J2 (TF-015) microSD card connector is wired correctly to the ESP32’s SPI interface (MOSI, MISO, SCLK, and a dedicated chip select pin), with proper pull-ups and bypass capacitors as needed.
  3. Power Input, Voltage Conversion, and Protection:
    • 12V Input & Protection:
      • Add a dedicated connector labeled “12V IN” to receive power from your benchtop 12V supply.
      • Immediately after the 12V IN, include a high-quality resettable PTC fuse and a TVS diode (with an appropriate clamping voltage) to protect against over-current and voltage surges.
      • Branch the 12V rail to a connector labeled “12V OUT” for fans or other 12V peripherals.
    • Buck Converters:
      • Add a quality buck converter to step 12V down to 5V. Route the 5V output to a dedicated connector labeled “5V OUT”.
      • Add a second buck converter to step 12V down to 3.3V, with its output connected to a dedicated connector labeled “3.3V OUT”.
  4. Sensor Board Interface:
    • Headers for Sensors:
      • Add SMD headers or quick-connect connectors to interface with 72 microswitch inputs.
      • Route these sensor signals to the appropriate inputs on the MCP23017 expanders.
  5. User Interface: Remote Start & Toggle Switch:
    • Remote Start:
      • Add a dedicated header for a remote pushbutton. This header will allow you to connect an external, vibration-resistant start switch to a designated ESP32 GPIO.
    • Toggle Switch:
      • Integrate an SMD on/off toggle switch into the power circuitry (ideally on the 5V rail) so that the circuit can be safely turned off.
  6. Thermal Management & Fan Control:
    • Fan Connector:
      • Add a connector labeled “FAN 12V OUT” that provides 12V to a cooling fan.
      • Include a MOSFET switching circuit (with a flyback diode across the fan) controlled by the ESP32 (using one of its GPIOs) for automated fan control.
    • Optional Temperature Sensor:
      • Optionally, add an SMD temperature sensor (such as an SMD LM35 or a digital sensor) near the regulators to monitor temperature for dynamic fan control.
Next Steps
  1. Apply Changes:
    Use the “Apply changes” function in Flux to update your project with these schematic modifications.
  2. Wire the Schematic:
    Connect all the components following the wiring plan above. Ensure that each net is clearly labeled (power rails, I²C bus, SPI for microSD, sensor lines, LED data outputs, etc.) and that proper decoupling is in place.
  3. Run DRC:
    Once wiring is complete, run the Design Rule Check in the REVIEW tab to verify that the schematic meets all design standards. Resolve any flagged issues.
  4. Proceed to PCB Layout:
    After the schematic is complete and error-free, transition to the PCB layout stage where you place the footprints and route the board.
This updated plan adds all the required parts and their interconnections. Let me know if you need step-by-step guidance on wiring specific sections or any further assistance before finalizing your schematic.
Apply changes and wire the schematic
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F1
U11
U2
U3
SW1
J2
C1
Capacitance
0.1uF
C2
Capacitance
0.1uF
LED1
U6
C3
Capacitance
0.1uF
U5
C4
Capacitance
0.1uF
U4
Q1
J1
  • Generic Inductor
    Generic Inductor
    A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
    jharwinbarrozo
    16.1k
  • Generic Capacitor
    Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Resistor
    Generic Resistor
    A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Ground
    Ground
    A common return path for electric current. Commonly known as ground.
    jharwinbarrozo
    20.5M
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
    natarius
  • Net Portal
    Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
    jharwinbarrozo
    43.0M
  • RMCF0805JT47K0
    RMCF0805JT47K0
    General Purpose Thick Film Standard Power and High-Power Chip Resistor 47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film Features: - RMCF – standard power ratings - RMCP – high power ratings - Nickel barrier terminations standard - Power derating from 100% at 70ºC to zero at +155ºC - RoHS compliant, REACH compliant, and halogen free - AEC-Q200 compliant
    jharwinbarrozo
    1.2M
  • 875105359001
    875105359001
    10 µF 16 V Aluminum - Polymer Capacitors Radial, Can - SMD 30mOhm 2000 Hrs @ 105°C #commonpartslibrary #capacitor #aluminumpolymer #radialcan
    jharwinbarrozo
    1.2M
  • CTL1206FYW1T
    CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric)
    jharwinbarrozo
    1.1M
  • 1070TR
    1070TR
    Battery Holder (Open) Coin, 20.0mm 1 Cell SMD (SMT) Tab bate or batt #forLedBlink
    jharwinbarrozo
    700.5k

HRG 1

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