Review Help: Custom ESP32-P4 Controller Design
Posted: Tue Apr 07, 2026 5:49 am
I decided to create my own custom Controller based on a Waveshare ESP32-P4 Module. 
Problem is, this is my first ever electronics project beyond grabbing a WeMos D1 Mini and slapping WLED on it via a website. So I've spent the past month or so reading, and learning, teaching myself electronics design, ripping apart other designs, and how to use KiCad.
High level overview is this is basically a door access controller. The P4 was chosen due to wanting Bluetooth, Wifi, & Ethernet connectivity with the ability to handle multiple USB Camera streams. Ultimately I want to have App control, with the ability to tie into voice assistants(Alexa, Siri, etc.), and home automation software.
As for the board:
There is a circuit that detects if the door is open or not, another to activate a solenoid, and of course a USB-A connector for a camera.
Power can be provided via an external 48V power supply, or if the Ethernet Module is installed it can be powered off POE++.
The board has 3x 4 pin heads that goto seperate DC-DC Buck Converter cards that take the 48v and create the needed +3.3v, +5v, and Solenoid voltage (+12v-36v).
The DSI has been exposed as 2 Lane to a 22 Pin FPC Connector for a local display.
There is an RJ45 connector onboard that is used to connect to a daughter board that expands the number of doors, solenoids, and cameras. The RJ45 passes the +48VDC, the I2C Bus, and the USB Hub's Channel 2. Current design allows for upto 4 Daughterboards in a Daisy-Chain. I don't expect the max run from the main controller to the first daughter board to be over 2m, and possible 10m to the very last one. All daughter boards have a P82B715 on the inbound side of the I2C bus, and their own 4 Channel USB Hub.
For the I2C bus I went with Potentiometers as the pullups in series with a 220ohm resistor. My reasoning for this is that I won't know the end configuration and pots allow some form of tweaking while the 220's give an absolute floor.
I've tried to expose every pin the ESP32-P4 module has for future use, with the exception of the CSI, as due to the distance limitation on that I decided it wasn't work the hassel.
I plan on using the IDC Antenna connector and not the internal antenna.
So, because this was cobbled together from many different datasheets, and schematics, and I don't fully 100% understand (yet) how some of this stuff works, or why certain things were chosen. I'm hoping you all will be willing to help me and just give it a once over to see if there is anything I did wrong, should change, or ways to improve the design.
I've attached the PNG & PDF versions of the schematic, and also, I have rough draft of the PCB done as well.. Tho it's an older revision that dosen't reflect some changes I've made so far.
Problem is, this is my first ever electronics project beyond grabbing a WeMos D1 Mini and slapping WLED on it via a website. So I've spent the past month or so reading, and learning, teaching myself electronics design, ripping apart other designs, and how to use KiCad.
High level overview is this is basically a door access controller. The P4 was chosen due to wanting Bluetooth, Wifi, & Ethernet connectivity with the ability to handle multiple USB Camera streams. Ultimately I want to have App control, with the ability to tie into voice assistants(Alexa, Siri, etc.), and home automation software.
As for the board:
There is a circuit that detects if the door is open or not, another to activate a solenoid, and of course a USB-A connector for a camera.
Power can be provided via an external 48V power supply, or if the Ethernet Module is installed it can be powered off POE++.
The board has 3x 4 pin heads that goto seperate DC-DC Buck Converter cards that take the 48v and create the needed +3.3v, +5v, and Solenoid voltage (+12v-36v).
The DSI has been exposed as 2 Lane to a 22 Pin FPC Connector for a local display.
There is an RJ45 connector onboard that is used to connect to a daughter board that expands the number of doors, solenoids, and cameras. The RJ45 passes the +48VDC, the I2C Bus, and the USB Hub's Channel 2. Current design allows for upto 4 Daughterboards in a Daisy-Chain. I don't expect the max run from the main controller to the first daughter board to be over 2m, and possible 10m to the very last one. All daughter boards have a P82B715 on the inbound side of the I2C bus, and their own 4 Channel USB Hub.
For the I2C bus I went with Potentiometers as the pullups in series with a 220ohm resistor. My reasoning for this is that I won't know the end configuration and pots allow some form of tweaking while the 220's give an absolute floor.
I've tried to expose every pin the ESP32-P4 module has for future use, with the exception of the CSI, as due to the distance limitation on that I decided it wasn't work the hassel.
I plan on using the IDC Antenna connector and not the internal antenna.
So, because this was cobbled together from many different datasheets, and schematics, and I don't fully 100% understand (yet) how some of this stuff works, or why certain things were chosen. I'm hoping you all will be willing to help me and just give it a once over to see if there is anything I did wrong, should change, or ways to improve the design.
I've attached the PNG & PDF versions of the schematic, and also, I have rough draft of the PCB done as well.. Tho it's an older revision that dosen't reflect some changes I've made so far.