• Status: Review
• Tabletop CubeSat ADCS test platform controlled by an ESP32-DevKitC (ESP32-WROOM-32 class, 38-pin).
• Scope is a complete professional electrical schematic only; PCB layout is excluded.

• Laboratory/tabletop ADCS algorithm and fault-injection prototype.
• Not flight hardware and not a certified mains product.

• Read LSM303AGR and MPU-6050 inertial sensors over one 3.3 V I2C bus.
• Receive GPS data over UART2 and provide Bluetooth telemetry using the ESP32 internal radio.
• Independently command three bidirectional 3 V brushed DC gear motors using PWM plus direction.
• Read three manual analog potentiometers and eight active-low fault switches.

• ESP32 controller with fixed GPIO map.
• LSM303AGR at 0x19 accelerometer / 0x1E magnetometer.
• MPU-6050 with AD0 high at 0x69.
• Exactly one shared 4.7 kΩ I2C pull-up pair.
• External NEO-6M/GPS 6MV2 connector with GPS_VCC marked TBD 3.3/5 V and 3.3 V-only logic requirement.
• Three protected DRV8838 PH/EN H-bridges, one per motor.
• Eight non-destructive active-low software fault inputs.

Text
AC mains -> external DZ30LE-32C10 RCBO/fuse-breaker -> external isolated JC-24-12 PSU -> 12 V / 2 A
  -> low-voltage protection -> +12V_PROTECTED
     -> 3.3 V buck -> ESP32 + sensors + GPS
     -> 3.0 V buck -> three motor H-bridges -> motors
ESP32 <-> I2C sensors; ESP32 <-> GPS UART; ESP32 -> motor PWM/DIR; pots/DIP -> ESP32 inputs

• Mains / isolated PSU: External devices represented only by interface connectors because exact JC-24-12 terminal pinout is unverified.
• 12 V entry: PTC, reverse-polarity ideal-diode controller stage, TVS, ceramic and bulk filtering.
• Regulators: Two LMR33630BDDAR synchronous bucks at 400 kHz.
• Controller: ESP32-DevKitC 38-pin compatible development-board symbol.
• Sensors: Bare LSM303AGR and datasheet-derived schematic-only MPU-6050 symbol.
• Motor drive: Three DRV8838 single H-bridges with default-low nSLEEP bias.

• I2C SDA GPIO21, SCL GPIO22.
• GPS UART2: GPIO16 RX from GPS_TX; GPIO17 TX to GPS_RX.
• Motors: M1 GPIO25/26; M2 GPIO27/14; M3 GPIO13/4 (PWM/DIR).
• Pots: GPIO34, GPIO35, GPIO32.
• DIP: GPIO5, 18, 19, 23, 33, 36/VP, 39/VN, 15.

• Source: isolated 12 VDC, 2 A nominal.
• No runtime target; mains-powered tabletop use.
• Source adequacy is TBD until all three motor stall currents are measured.

• Professional schematic with real library parts and datasheet-backed support networks.
• Schematic-only custom MPU-6050 part has no PCB footprint because PCB layout is out of scope.
• Mains assembly and wiring require qualified review and enclosure/protection design.

• Fault inputs are active-low and externally pulled high.
• GPIO5 and GPIO15 switches must remain open/HIGH during reset unless boot behavior is verified.
• Motor outputs must stay disabled until firmware intentionally drives each nSLEEP high.
• ADC calibration/attenuation is required for the 0–3.3 V potentiometer range.

• Functional blocks arranged left-to-right with external interfaces at edges.
• SENSOR_GND and MOTOR_GND are separate return domains joined once at the protected-entry star point.

• DRV8838 selected because its PH/EN interface directly matches fixed DIR/PWM GPIOs.
• LMR33630BDDAR selected for both rails to avoid 12-to-3.x V LDO dissipation.
• GPS supply is explicitly selectable/TBD; GPS logic must remain 3.3 V compatible.
• Fault injection is software-only; no DIP switch directly interrupts power or motor wiring.

• ESP32-DEVKITC-32UE 38-terminal library symbol is pin-compatible for the requested ESP32-WROOM-32 DevKitC interface; module antenna suffix must be verified before procurement.
• External DZ30LE-32C10 and JC-24-12 blocks are off-board and exact terminal markings remain TBD.
• Motor nominal and stall currents are unknown.

• Initial schematic architecture and component selections defined from the user brief.