PCB Design Feedback Request: ESP32, SIM808, and Sensor Integration

[achraffff]

Hello everyone,

I'm working on a 4-layer PCB design and would appreciate any feedback or recommendations you might have. Here are some key details of the design:
- Microcontroller: ESP32-C3FH4 for control and communication
-heavy_check_mark: GPS/GPRS Module: SIM808, with SIM card support
-heavy_check_mark: Sensors:
• MLX90614 for temperature measurement
• MPU-9250 for acceleration sensing
• APDS-9960 for proximity detection
-heavy_check_mark: Power Management: TP4056 module for LiPo battery charging and seamless switching between USB, battery, and external power
-heavy_check_mark: Antenna Connections: Separate GSM and GPS antennas for the SIM808

-heavy_check_mark: Layer Configuration:

-heavy_check_mark: 4-Layer Stack:
• Top Layer: Signal
• Inner Layer 1 : Power
• Inner Layer 2 : Ground
• Bottom Layer : Signal

-heavy_check_mark: Design Goals and Specific Areas for Feedback:

1. Power Supply Stability: I'm particularly concerned about ensuring stable power to the SIM808 module. The power circuit includes components for USB/battery power switching. Any suggestions on component selection, layout, or decoupling for power stability?
2. Power Consumption Optimization: I'm exploring power-saving features such as ESP32 deep sleep. Would love advice on component adjustments or layout techniques to reduce overall consumption.
3. I2C Communication Reliability: This design involves multiple I2C devices connected to the ESP32-C3. Feedback on pull-up resistor values or tips for improving I2C communication stability would be very helpful.
4. Antenna Placement and Routing: Since I have GSM and GPS antennas for the SIM808, I want to ensure optimal placement and minimal interference. Any best practices on antenna layout, ground plane isolation, or signal routing?

I've attached the schematic and PCB layout below. Looking forward to any insights you can provide to help make this design more robust and efficient.

Thanks in advance for your help!   [

[Kean]

As a start, I think your antenna placement and RF traces are a show stopper.
The traces are far too long and need to be both impedance matched and kept away from other signals.
Not sure which WiFi antenna you are using, but is probably not going to work well without more space around it.  Some virtual antennas do use tricks to handle this.
It also looks like you have the GPS antenna center pin going through the SIM808 module (or underneath it which isn't really possible to assemble.
I stopped looking at that point because you'll likely need to change the layout significantly to get the RF stuff sorted.

[PlainName]

This is another spam post - original (on this forum) here: https://www.eevblog.com/forum/projects/requesting-feedback-on-pcb-design-for-esp32-c3-sensors-and-sim808-module

Don't bother replying to it, please.

[Simon]

This is another spam post - original (on this forum) here: https://www.eevblog.com/forum/projects/requesting-feedback-on-pcb-design-for-esp32-c3-sensors-and-sim808-module

Don't bother replying to it, please.

Please clarify where the spam is.

[PlainName]

Did you click the link in my post? It's in the projects forum, and you just commented to that thread!