Custom ESP32-S3 Baseboard Design
Worked for 4 mins 20 sec
Progress made:
- Renamed the project and updated the description.
- Created/updated project files for the system architecture, GPIO map, external regulated 5V input, >5A power-path requirement, and external
MAIN_POWER_SWITCHconnector 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 intoSERVO_5VandLOGIC_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.
Wire power tree
Use Option A
Add capacitors
Run ERC
Add mounting holes
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ESP32-S3 Servo Load Controller - Project Specification
Scope
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.
- Peripherals: SPI TFT, I2C OLED + 3x INA226, COM2 UART, buzzer driver.
- Outputs: normal low-side MOSFET channels with inverted NPN gate drive and status LEDs.
- Special filter relay channels: 3 identical LC/RC channels with A/B screw terminals, 2x 100 uH inductors >=2 A, 100 nF/50 V, 1 uF/50 V, 100 kOhm, MOSFET relay element, status LED.
GPIO allocation
Table
| Function | GPIO |
|---|---|
| Servo 1 PWM | GPIO4 |
| Servo 2 PWM | GPIO5 |
| Servo 3 external PWM | GPIO6 |
| TFT MOSI | GPIO11 |
| TFT SCLK | GPIO12 |
| TFT CS | GPIO10 |
| TFT DC | GPIO9 |
| TFT RST | GPIO8 |
| I2C SDA | GPIO21 |
| I2C SCL | GPIO47 |
| COM2 TX | GPIO17 |
| COM2 RX | GPIO18 |
| Buzzer | GPIO3 |
| Filter relay CH1 | GPIO13 |
| Filter relay CH2 | GPIO14 |
| Filter relay CH3 | GPIO15 |
| Normal MOSFET OUT1 | GPIO16 |
| Normal MOSFET OUT2 | GPIO35 |
| Normal MOSFET OUT3 | GPIO36 |
| Normal MOSFET OUT4 | GPIO37 |
Layout rules to enforce later
- ESP32 antenna at board edge with no copper/traces under antenna region on any layer.
- Servo/high-current returns route back to power entry, not through ESP32/TFT/I2C/INA226 areas.
- SPI SCLK short and away from MOSFET drains, filter channels, servo PWM, and high-current loops.
- I2C and INA226 sense wiring away from 12 V switching/filter loops.
- Servo +5 V traces/copper: preferred >=2 mm, absolute minimum 1.5 mm.
- Logic 5 V traces >=0.5 mm; signals >=0.25 mm.
- 12 V/load/filter/sense traces sized for real current; use copper pours where needed.
Scope
Critical assumptions to verify before manufacturing
Functional blocks
GPIO allocation
Layout rules to enforce later
