Datasheet check is partly complete: the high-current P-MOSFET reverse-protection part is suitable for the 5A+ path, and the NPN driver part is suitable for GPIO gate/buzzer drive. I’m now selecting the safest electronic switch part for the three special floating A/B filter channels before adding the full schematic.
Created/updated project files for the system architecture, GPIO map, external regulated 5V input, >5A power-path requirement, and external MAIN_POWER_SWITCH connector approach.
Added the main schematic components: ESP32-S3 44-pin DevKit placeholder, high-current P-MOS reverse-polarity MOSFET, 5V/12V screw terminals, servo/OLED/UART/TFT/INA226 connectors, normal MOSFET output hardware, buzzer, flyback diodes, and 3x solid-state MOS-output relay parts for the special filter channels.
Verified key datasheet points for the P-channel MOSFET and 2N3904 driver; the ESP32-S3 DevKit exact N16R8 footprint still must be confirmed before manufacturing.
Current state:
Components have been added, but the schematic is not wired yet.
No PCB layout has been started.
Review/ERC has not been run yet.
Remaining work:
Add passive parts: bulk capacitors, decoupling capacitors, I2C pull-ups, gate/base resistors, LED resistors, LC/RC filter components, and mounting holes.
Wire the 5V input path through reverse-polarity protection and MAIN_POWER_SWITCH, then split into SERVO_5V and LOGIC_5V.
Wire ESP32 GPIOs to servos, TFT, I2C, UART, buzzer, normal MOSFET outputs, and filter relay channels.
Wire the 3 special filter channels exactly per your A/B, C1/C2/R1, L1/L2, and MOSFET relay topology.
Run review/ERC and fix violations.
Confirm the exact ESP32-S3 N16R8 44-pin board footprint/pinout before layout/manufacturing.
Robust ESP32-S3 N16R8 44-pin DevKit/baseboard for 3x MG90S servos, SPI ILI9341 TFT, I2C OLED, 3x INA226 plug-in modules, COM2 UART, active buzzer, normal 12 V MOSFET outputs, and 3x special 12 V two-core LC/RC filter relay channels.
Critical assumptions to verify before manufacturing
Exact ESP32-S3 N16R8 44-pin DevKit pinout and mechanical footprint must be confirmed from the purchased board.
TFT module must accept 3.3 V SPI logic when powered from 5 V.
OLED and INA226 modules must not pull SDA/SCL to 5 V. Preferred board pull-ups are to 3.3 V only.
Special filter relay switching behavior must be bench-tested on one channel: the provided topology is a filtered shunt/bridge between A and B after L1/L2, not a series interruption of one conductor.
Main 5 V source is an external regulated 5 V DC adapter/module supplied by user. No onboard 5 V regulator is used for the main rail.
Main power switching uses an external high-current panel-mount switch wired to a PCB connector labeled MAIN_POWER_SWITCH. Do not use a small low-current PCB slide switch in series with servo current.
5 V input path, switch loop, and servo branch must be sized for at least 5 A, preferably 6 A or more.
Normal MOSFET output count is assumed as 4 channels unless revised; GPIOs planned: GPIO16, GPIO35, GPIO36, GPIO37.
Use 2-layer PCB, 1 oz minimum, 2 oz preferred for servo/load current. Bottom layer is continuous GND plane with antenna copper keepout.
Functional blocks
Power input/protection: external regulated 5 V screw input, P-channel MOSFET reverse-polarity protection, external MAIN_POWER_SWITCH loop, protected/switched 5 V rails.
Servo power: separate high-current 5 V branch with 1000 uF bulk capacitor and local 100 nF capacitors.
Logic/module power: ESP32 VIN/5V, TFT/OLED/INA226/UART/buzzer/MOSFET gate pull-ups, 100 uF and local 10 uF/100 nF decoupling.
ESP32-S3 DevKit interface: 44-pin footprint/header with GPIO silkscreen labels and boot-sensitive pin restrictions.