Modular PCB Design for Smart PBR
reviewed connectivity and routing status
0:36
fixed obvious power and output nets
3:20
- Connected U1:FB to ^REG5_FB
- Connected Q2:S to ^GND
- Connected J2:2, J4:2 to ^VIN_12V
- Set Layout's traceWidth to "0.20mm"
- Set Layout's keepOut to "0.20mm"
- Set Layout's boardInsetMargin to "0.50mm"
Execution stopped due to insufficient credits.
1:26
Started implementing a plan
#Goal
- Complete the remaining schematic connections and PCB routing of the ESP32 PBR Controller so that the design becomes prototype-ready.
#Implementation plan
1. Complete Schematic Connectivity
1. Review the power/output sections and connect any remaining components, ensuring proper connections between the power supply, regulators, sensors, and actuators.
2. Verify routing connections to test-points, headers, and connectors for complete signal continuity.
2. Organize PCB Zones
1. Divide the board into distinct areas for power, logic (ESP32 and control circuitry), analog sensing, and high-current outputs.
2. Clearly label each zone and review net assignments to avoid cross-zone interference.
3. PCB Routing
1. Apply layout guidelines specific to each zone, ensuring appropriate trace widths and clearance for power, signal, and high-current paths.
2. Use auto-routing to connect nets within each zone while manually reviewing critical paths, especially in power and high-current outputs.
3. Validate connectivity using design rule checks to ensure no unrouted or conflicting connections remain.
4. Final Review
1. Cross-check the schematic against the PCB layout ensuring all components are correctly routed and connected.
2. Update project documentation with the final schematic and board routing changes.
#Success criteria
- All schematic connectivity issues, especially in the power and output sections, are resolved.
- PCB is fully routed with axes segmented into power, logic, analog, and high-current zones.
- Design rule checks confirm a complete connection with no errors, making the design ready for prototype review.
- 12 V DC input via 2-pin screw terminal
- Reverse-polarity protection on input
- Protected 12 V rail feeds 5 V buck converter
- 5 V rail feeds a 3.3 V LDO for ESP32 and logic peripherals
- ESP32 dev board mounted on dual headers for beginner-friendly replacement
- Connectorized sensor interfaces for pH, dissolved oxygen, oxygen concentration, DS18B20, and MH-Z19B
- Actuator interfaces for two PWM LED channels, 4-channel relay module, pump, and solenoid valve
- I2C peripherals for LCD and DS3231 RTC
- SPI connector for SD card module
- Test points for VIN, 5 V, 3.3 V, GND, I2C, SPI, UART, and PWM signals
- Reverse-polarity protection: series Schottky diode for simple, robust beginner-friendly input protection
- 12 V to 5 V conversion: buck regulator IC/module from Flux library sized with margin for relay module plus peripherals
- 5 V to 3.3 V conversion: LDO regulator for cleaner logic rail and simpler design
- One continuous common ground across analog, digital, and power sections with physical separation rather than split grounds
- Single pair of I2C pull-ups for the bus, configurable by population if external modules already include them
- I2C: ESP32 GPIO21 SDA, GPIO22 SCL
- SPI SD: GPIO18 SCK, GPIO23 MOSI, GPIO19 MISO, GPIO5 CS
- MH-Z19B UART: GPIO16 RX2, GPIO17 TX2
- DS18B20: GPIO4
- PWM LED Red: GPIO25
- PWM LED Blue: GPIO26
- Analog pH: GPIO34
- Analog DO: GPIO35
- Analog O2 concentration: GPIO32
- Relay IN1..IN4: GPIO27, GPIO14, GPIO13, GPIO33
- Power entry and buck section near one board edge
- High-current LED / pump / solenoid / relay connectors grouped away from analog sensor inputs
- ESP32 centered between low-power interfaces and high-power outputs
- Analog sensor connectors routed away from buck switching node and PWM current loops
Project
Architecture Summary
Chosen Defaults
Planned GPIO Mapping
Layout Intent
