The WiCAN PRO schematics are now available on GitHub. In this update, I’ll discuss the hardware and some interesting design features.

USB Switch

WiCAN PRO can act as a USB device (USB to serial via the CH342F chip), making it versatile as a USB to OBD adapter or a USB to CAN interface for users who prefer wired connections, such as in car racing and Realdash application. It can also be used for development and debugging. When a USB device like the ESPNetLink or other peripherals are connected to the WiCAN USB-C OTG port, the USB power output will turn on, sourcing current. The ESP32 will then toggle the USB switch to connect to the ESP32 USB pins, enabling the use of the WiCAN PRO as a USB host.

SD-CARD Logging

WiCAN PRO’s SD card operates in 4-bit mode with the ESP32-S3 SDIO controller, offering excellent performance. It also features an RTC (Real-Time Clock) to ensure accurate timestamps, supported by small capacitors that maintain power for a few minutes even when the battery is disconnected or the device is unplugged from the OBD port. This logging feature is particularly useful for users who prefer to log data to an SD card instead of relying on LTE connectivity. Once they return home, the data can be uploaded to Home Assistant automatically.

LED Controller

WiCAN PRO features an RGB LED controlled via I2C. This small but useful feature is valuable for debugging connectivity and status. Additionally, the LED can function as a breathing light when the device is in deep sleep mode, without drawing much extra current.